Classification of Geraniales: 14 Families | Dicotyledonae

In this article we will discuss about the classification of Geraniales. According to Engler, Geraniales consists of fourteen families:- 1. Geraniaceae 2. Oxalidaceae 3. Tropaeolaceae 4. Balsaminaceae 5. Linaceae 6. Zygophyllaceae 7. Rutaceae 8. Simarubaceae 9. Burseraceae 10. Mieliaceae 11. Malpighiaceae 12. Polygalaceae 13. Euphorbiacea 14. Buxaceae.

Family # 1. Geraniaceae:

Annual herbs or undershrub’s, rarely shrubs. Leaves simple, palmately lobed or incised or compound, stipulate, alternate or rarely opposite. The inflorescence is a few- flowered scorpioid cyme or many-flowered cymes clustered in the form of an umbel J or flowers may be solitary.

Flowers bisexual, actinomorphic, rarely zygomorphic, hypo­gynous. Sepals 5, rarely 4 or 8, free or rarely connate, more or less imbricate; in zygo­morphic flowers the posterior sepal is spurred.

Petals as many as sepals, imbricate, rarely twisted; nectar glands alternating with petals. Stamens 10 in 2 whorls, obdi­plostemonous, often 15, rarely less than 10, 9 or 7 or even only 2; filaments united at base, rarely completely free, rarely few stamens are reduced to staminodes; anthers pendulous, bithecal, with small connectives.

Carpels 2-5, rarely 8; ovary syncarpous with as many cells as there are carpels, superior; style one with as many stigmatic branches as there are cells in the ovary; stigmas ligulate; ovules 2 in each cell, pendu­lous, superposed, campylotropous, with upwardly directed micropyle and ventral raphe, rarely ovules many or solitary in each cell; placentation axile.

Fruit a capsule, dehiscing into as many parts as there are carpels and roll up or become spirally twisted along the beak-like style, i.e. divided into mericarps. Seed without or with scanty endosperm and a curved embryo; the cotyledons folded.

In some cases there is a rhizome at the base or the base is tuber-like. Dirachma socotrana Balf. f. is a shrub. The small leaves in Sarcocaulon are metamorphosed into spines. Geranium Wallichianum D. Don and Pelargonium zonale L’Her. have large stipules.

The leaves in this family are glandular hairy, the glands containing fragrant Volatile oil. The stomata are ranunculaceous type. The flowers of Vivania have 4 sepals and the fruit dehisces loculicidally. In Biebersteinia the 5 carpels are free below united above in a single style; fruits are 5 small nuts.

The typical floral formula is as given here:

The peculiar anatomical feature is the continuous ring-like pericycle of schleienchymatous cells, several layers thick. The vascular bundles are in alternating smaller and larger groups. Perforations are simple or often scalariform, and interyascular pitting is alternate. In secondary xylem secondary rays are lacking. In some Geranium species the pericycle lies above phloem.

The family with about 750 species under 11 genera is distributed in the temperate and tropical countries while a few are alpine. Some are xerophytes and occur in the steppes. Sarcocaulon is found in S. African deserts.

Several species of Geranium are found in the Himalayas and hills of E. India. Pelargonium zomle L. and a few other species of the genera are cultivated in the cooler parts of the country for the beautiful flowers. An essence known as Geranium-oil is obtained not from any species of Geranium but from Pelargonium graveolens L. Her., P. odoratissimus Ait., P. capitatum Ait. and P. rodule L. Her.

Geraniaceae is closely related to Oxalidaceae and Tropaeolaceae. The floral characters as well as the wood anatomy in the 3 families are very similar. Cytological evidence also proves that they are close to each other. Older workers like De Candole, Bentham and Hooker, did not distinguish Oxalidaceae and Tropaeolaceae from Geraniaceae.

Engler splitted the large family into 4 distinct families e.g. Geraniaceae, Oxalidaceae, Tropaeolaceae and Balsaminaceae. The first three be placed in the order Geraniales while Balsaminaceae was placed by him in the order Sapindales.

Later workers recognising the closer affinity of Balsaminaceae to the other 3 families transferred Balsaminaceae to, Geraniales from which many other families included in that by Engler have been removed by them. According to Cronquist Geraniales with these 4 families and Limnanthaceae has been derived from Sapindales.

Family # 2. Oxalidaceae:

Perennial herbs with underground rhizomes, bulbs or corms, rarely short trees Leaves radical or cauline, whorled or alternate, pinnately or palmately compound, rarely simple, exstipulate or stipulate. Flowers in cymes or cymose umbels, or solitary, axillary or terminal, regular, bisexual, hypogynous, pentamerous. Sepals 5, imbricate, rarely twisted; petals 5, twisted.

Stamens 10 in 2 whorls, obdiplostemonous, i.e. the outer antipetalous, inner antisepalous, often stamens 15 in 3 whorls, united at the base; anthers bithecal, dehiscing longitudinally, connective small.

Ovary superior, 5-locular and 5-lobed, styles 5, stigmas capitate; ovules 1-many in each cell; rarely ovary 3-locular and 3-lobed with only one style. Fruit a loculicidal capsule dehiscing elastically or the fruit is a berry. Seeds with, straight embryo and fleshy endosperm, Sometimes arillate; aril springs off elastically with the seed.

Although predominantly herbaceous the family includes 2 genera of trees, viz. Averrhoa and Connaropsis. The leaves of most species show sleep movement and in Biophytum these are sensitive to touch.

Calcium oxalate crystals are present in the cells of the green tissues. The petiole is modified into a flat phyllode in some case… In Lepidobotrys and Hypseocharis the ovary is tricarpellary and 3-locular with a single style. Fruits of Averrhoa are berries.

The vascular anatomy shows that the vessel., are arranged in 4 or more cells; intravascular pitting is alternate and large; perforations are simple. Fibres are septate with simple pits. The pericycle is a continuous ring and is made up of sclerenchymatous cells, several layers thick.

The family consists of about 900 species in 8 genera of which Oxalis alone has about 800 species. The plants of the family are distributed in the tropical and temperate regions, the majority occurring in S. America. In India we have Oxalis corniculata Linn., Averrhoa carambola Linn., Biophytum sensitivum DC. etc.

The plants are not of much econo­mic importance. The berries of Averrhoa carambola (Kamrak or Kamranga). is acidic with a pleasant flavour and is eaten raw or cooked. A few species of Oxalis are cultivated for the small beautiful flowers and a few have medicinal value. O. tetraphylla Cav. as well as a few others have tuberous roots which are edible.

Oxalidaceae is closely allied to Geraniaceae in which it was formerly included and later treated as a distinct family by Engler. The structure of the-flower, the fruit and the vascular anatomy are more or less similar in, both the families.

The 2 families are placed side by side in the same order by all workers of Angiosperem taxonomy. The 2 genera of trees, viz. Averrhoa and Connaropis are now placed by some in a distinct family Averrhoaceae.

Family # 3. Tropaeolaceae:

Herbs usually with soft prostrate stem, often climbing with the help of long petioles. Leaves alternate, simple more or less lobed, peltate, exstipulate.

Flowers solitary, axillary, bisexual, zygomorphic, hypogynous. Sepals 5, usually coloured, the posterior is prolonged into a spur. Petals 5, free, clawed, the posterior pair near the mouth of the spur are slightly smaller and situated a little above the anterior three which are larger and fringed on the margin.

Stamens 8 in 2 whorls. Carpels 3; ovary syncarpous, 3- locular, 3-lobed, superior; ovule anatropous, 1 in each cell, pendulous; style solitary with 3-fid stigma. Fruit a 3-seeded schizocarp separating into 3 one-seeded drupelets. Seeds without endosperm and thick cotyledons which are often slightly coalescent; embryo straight.

Floral formula:

The family consists of about 90 species in 2 genera occurring in the hilly areas of America. Tropaeolum majus Linn, is much cultivated for the large beautiful flowers. The plants have an acrid taste like that of a Nasturtium plant (Cruciferae), that is why it is called Garden-Nasturtium.

The leaves of this plant are used to make sandwiches; T- tuberosum Linn, a Peruvian plant has edible tuberous roots. The family is closely allied to Geraniaceae. Oxalidaceae and Balsaminaceae, the four being formerly included in a single family Geraniaceae by earlier workers.

Family # 4. Balsaminaceae:

Herbaceous annuals with brittle translucent stems with watery juice and swollen nodes. Leaves simple, alternate, opposite or whorled, exstipulate, often with stipulary glands at the base of the petioles. Flowers solitary and axillary or in lax axillary cymes or panicles with slender peduncles and pedicels, bisexual, strongly zygomorphic, hypo­gynous and pentamerous.

Sepals petaloid, imbricate; the posterior the largest and prolonged into a nectariferous spur; the 2 anterior ones much smaller and sometimes altogether suppressed and the lateral sepals come to anterior position. Of the 5 petals the posterior petals are united to the laterals, so that apparently there are 3 petals; the anterior one is the largest and cover the other petals in bud.

Stamens 5, filaments short and broad, anthers bilocular, introrse, both filaments and anthers unite to form a hood over the gynoecium; ultimately the anthers break at the base and are carried up by the growing gynoecum. Disc absent.

Ovary superior, of 5 united carpels, 5-celled, with a 5-toothed sessile stigma; ovules many, pendulous on axile placentation and one seriate in each cell, or ovules 2-3 in each cell.

Fruit a loculicidal capsule, bursting on maturity to a slight touch or pressure ejecting the seeds to a considerable distance while a central column of the capsule persists, or the fruit is a drupe with a bony 5-celled stone. Seeds with a straight embryo and without endosperm.

The family consists of only 2-genera of which Impatiens has over 500 species. Hydrocera is a monotypic genus occurring in Bengal.

Impatient has most of the species growing in tropical mountains of Asia and Africa, and a few in N. Asia, Europe, N. America and S. Africa. Species of Impatiens grow in damp situations while Hydrocera is an aquatic with floating stems. I. nolitangere Hook, and I. parviflora Royle are found in Europe. I. balsamina Linn, is cultivated in almost all countries. I. fulva Nutt. an American plant has been naturalised in many parts of Europe. In India about 230 species are found to grow wild in the hills at lower elevations.

Raphides occur in almost all cells and hydathodes are present on the leaf margin of Impatiens. The stem of Hydrocera is fistular. In this genus the stamens are syngeneseous and the petals are free. The fruit of Impatient is a capsule while it is a drupe in Hydrocera with only 5 seeds.

Floral formula:

Balsaminaceae is closely allied to Tropaeolaceae, having a spur on the sepal and similar pollens. It is therefore placed in Geraniales by most authors with Geraniaceae Oxalidaceae and Tropacolaceae, which are predominantly herbaceous and have capsular fruits. Cytological evidence also supports this.

Engler included Balsaminaceae in Sapin- dales as the ovules have dorsal. Further in Balsaminaceae the spur is an outgrowth of the sepal whereas in Geraniaceae and Tropaerapheolaceae receptacular tissues are also involved in the spur formation.

Family # 5. Linaceae:

Annual or perennial herbs, under-shrubs or shrubs, rarely climbing, very rarely trees. Leaves simple, sessile, alternate or opposite, ex-stipulate or with small stipules, which are often caducous.

Inflorescence is a dichasial cyme, or a raceme or spike, often a cymose umbel, or flowers slolitary. Flowers actinomorphic, bisexual, hypogynous. Sepals 5, free or more or less connate, imbricate or valvate, usually persistent, rarely caducous. Petals 5, twisted in bud, clawed, with pocket-like slits or ligulate.

Stamens as many as petals or twice, thrice or 4-times as many; filaments broader near the base, united in a tube below, with nectar-glands outside; anthers bithecal, introrse, dehiscing by lateral slits; connective acute at apex; rarely some stamens are reduced to staminodes; often an extra or inter-staminal disc is present, free or adnate to the staminal tube.

Carpels 5 or 3, united to form a 5 -or 3-ceiled ovary, or the cells double that number due to a partition formed by the intrusion of the ovary wall; the partition is often incomplete, ovary superior; styles free, as many as carpels; ovules 2 in each cell or one if the partition wall is complete, anatropous, pendulous; funicle long; raphe ventral; an obturator is often present at the micropyle.

Fruit a septicidal capsule, dehiscing into 2-valved cocci. Seeds often arillate or with an winged appendage; testa shining; endosperm scanty, fleshy; embryo straight or slightly curved.

Stipules are represented by glands in some species of Linum and Hesperolinon. Hugonia and Durandea are climbers, climbing by hooked branchlets and peduncles. Branching is dichotomous in Radiola, the flowers of which are tetramerous. In Hesperolinon congestum Small and in a few species of Linum the calyx is caducous. Carpels are 2 in Nectaropetalum forming an 1-celled ovary with only 1 ovule.

The anatomical feature is more or less similar to Geraniaceae. The pericycle is a continuous ring of schlerenchyma often having fibres which are long and pointed. The xylem vessels are solitary, large, with simple or often scalariform perforations. Bordered pits are found on the walls of the fibres.

Floral formula:

The family with about 300 species in 1-3 genera is found in the tropical countries while a few occur also in the temperate regions. Reinwardtia cicanoba Hara occurs in the hills of India in temperate zone while R. indica Dum grows in the plains as well as in the hills at lower elevations. Linum usitalissimum L. is cultivated in India as well as in other countries for the seeds which yield an oil much used in paints and varnish.

A fine quality of fibre is also obtained from this plant which is woven into the linen cloth. This is a tall variety much cultivated in Russia and other European countries. It is the Tisi or Masina plant of India. Species of African genus Hugonia have edible fruits. Ctenolophon parvifolium Oliv. is a good timber tree. Root of Hugonia mystax Linn, is a cure for snake bite.

Linaceae closely resembles Geraniaceae in floral as well as anatomical characters. It is also allied to Humiriaceae and Erythroxylaceae and the 3 families are placed in a distinct order Linales by Cronquist. It comes closer to Polygalaceae as regards the anatomical structure of the stem is concerned.

It resembles Zygophyllaceae to some extent having regular and hypogynous flowers, obdiplostemonous androecium and anatropous ovules with ventral raphe. Bessey considers that Linaceae is related to Malvaceae as it is to Geraniaceae.

Family # 6. Zygophyllaceae:

Herbs or shrubs, rarely trees; branches often articulate. Leaves pinnate or 2- foliolate, rarely simple, opposite or alternate, leaflets entire; simple leaves entire or multifid; stipulate, stipules often spine scent. Inflorescence is cymose, terminal or axillary, often flowers solitary and axillary.

Flowers hermaphrodite, actinomorphic, rarely zygomorphic, hypogynous, often with a pair of small bracts. Sepals 5 or 4, free or rarely connate below, imbricate, or valvate, rarely open in bud. Petals 5 or 4, free, imbricate or contorted, rarely valuate; rarely petals absent. Disc often present, convex or depressed, rarely annular, eglandular.

Stamens in one, two of- three whorls, 5 or 4 in each, obdiplostemqnous; filaments often unequal, with scaly appendages at base, those of the outer whorl often adnate to the petals; anthers introrse, bilocular, dehiscing by lateral slits.

Carpels 5 or 4, united to form a 5-4-chambered syncarpous ovary; ovary superior, often stipitate, lobed or angled; the locules often partically trans­versely septate; style terminal, often slightly gynobasic, with ridges and furrows, stigmatic on the angles or with simple capitate stigma, or with 5 stigmatic branches; ovules 1-many in each cell, ascending or pendulous from an axile placenta, with ventral raphe.

Fruit a capsule or a schizocarp breaking into 2-10 spiny cocci, very rarely berry-like., Seeds pendulous; endosperm absent or scanty, fleshy or horny; embryo straight or curved.

Guiacum of tropical America and Balanites of W. Asia are trees. The rest are mostly dwarf shrubs. Neoleuderitzia has unisexual flowers. Flowers in Militanthus and Seetzenia are apetalous.

Diverse types of pollens are met with in this family. Kalstroemia has the gynoecium with 8-12 carpels. Peganum has a baccate fruit; Mtraria and Balanites have drupaceous fruits; the rest have capsules or schizocarps. The fruiting carpels of Tri- bulus are septate.

The family consisting of about 25 genera and 200 species is found in the warmer parts of the world especially in arid zone. Balanites aegyptiaca Del. grows in India and extends westwards to North Africa.

It is the Ingudi Briksha or Hingul which yields an oil from the seeds. Peganum harmala Linn, and Tribulus terrestris L. have also the same distribution; the former yields a red dye and the latter called “Gokshur” in Sanskrit is a reputed medicinal plant.

The wood of Guiacum officinale L. is the Lignum—vitae which gives the resin called gum-guiacum reputed to have medicinal value. The wood of G. officinale and G. sanctum Linn, as well as of Bulnesia arborea Eng. and B. sarmientis Lor. is very hard and heavy and the timber is valuable.

The peculier anatomical feature in this family is that the wood elements is in stories which vary from 8-17 per mm. Fusiform parenchymatous cells predominate and tracheids are present. Vessels are solitary with simple perforations. Fibres are bordered pitted.

The family is closely related to Rutaceae. The genus Peganum is intermediate bet­ween the two families and by some it is placed under Rutaceae. Hutchinson includes Zygophyllaceae in Malpighiales which is far removed from Rutales.

The relationship Zygophyllaceae with Malpighiaceae has been recognised also by Takhtajan who inclu­des both these families in Geraniales. Cronquist places Zygophyllaceae in Sapindales wherein he includes Rutaceae. The family Zygphyllaceae resembles Euphorbiaceae to some extent: the fruit is often a schizocarpic capsule in both families.

Family # 7. Rutaceae:

Shrubs or trees, usually armed; rarely herbs. Leaves usually compound, alternate or opposite, exstipulate, pellucid gland-dotted. Inflorescence racemose or cymose, or the flowers solitary. Flowers actinomorphic rarely zygomorphic, bisexual, very rarely unisexual, hypogynous.

Sepals 5 or 4, free or connate, imbricate. Petals 5 or 4, free, rarely connate, imbricate or rarely valvate. Stamens as many as petals or double the number, often many; filaments usually free, obdiplostemonous, often polyadelphous; anthers bilocular introrse. An annular disc or a gynophore is present above the androecium.

Carpels 4-5, united to form a 4-5-locular superior ovary; sometimes the carpels are loosely united or free at the base with a united style; ovary is usually more or less deeply grooved and the style is short often somewhat gynobasic; stigma capitate; carpels often less than 4 and rarely up to 12; ovules 1-2 in each cell with ventral raphe on axile placentation, often ovules more than 2. Fruit a hesperidium or amphisarca, or capsule; seeds with or without endosperm and often polyembryonic.

The armed species have thorns which are metamorphosed branches or have spines which are modified leaves. Simple leaves are found in Calodendron, Diosma, Adenandra etc. Leaves of Citrus are unifolilate compound (it is simple according to some authors). Leaves of Aegle and Triphasia are trifoliate; in Murraya they are pinnate, bipinnate in Ruta and tripinnate in Boenninghousenia.

Flowers are tetramerous in Achronychia, Boenninghousenia and a few other genera, and trimerous flowers are found in Triphasia and Lunasia, while pentamerous flowers are found in most genera. Unisexual flowers occur in Toddalta, Xanthoxylum and Empeleurum. The flowers of Dictamnus, Galipea and Alnicida are zygomorphic. Petals are free but in Correa, Ticorea, Galipea, etc. corolla is gamopetalous.

Stamens are polyadelphous in the family but in some Atalantia stamens are monadelphous. Diplostemonous androecium is met with in Fagara. Teclea and Empleurum have monocarpellai y ovary.

Carpels are entirely free in Xanthoxylum, Choisya, Evodia, Correa, etc. Fruit is capsular or drupaceous or berry-like. In Spathelia it is a winged drupe. In- Chloroxylon the seeds are winged. The fruit of Aegle is an amphisarca while that of Citrus is a hesperidium.

Floral formula is generally expressed as;

The stem anatomy shows the presence of isolated strands of sclerenchymatous fibres in the pericycle which in some cases unite to form a continuous ring. Vessels are in multiples and usually small; perforations simple; xylem parenchyma usually sur­rounding the vessels. Pits are simple or indistinctly bordered.

The family with about 1200 species in 120 genera is distributed in the tropical and subtemperate parts of the world, and quite a few of them are xerophytic.

It is well represented in India by about 70 species, e.g. many species of Citrus, Aegle marmelos Cor. Murraya paniculata Jack and M. Koeningii Spr. Glycosmis arborea (Roxb.) DC., Atalantia monophylla Corn. etc. are common in the plains, while Skimmia lauriola Hook, f., Boen-ninghousenia albiflora Reichb. f., species of Fagara are found in the hills.

Ruta graveoleus Linn, is medicinally important and used as a pot herb. Pilocarpus pennatifolius Lam. vields the oil of Jaborandi. Esenbeckia febrifuga A. Juss. and Tiwria febrifuga St. Hill, both Brazilian, are used as substitutes of Cinchona, Aeagle marmelos Corr. is the Bael tree, famous for its large delicious fruits which also have medicinal properties.

The trifoliate leaves are much wanted in religious ceremonies by the Hindoos, Limonia acidissima Linn, has similar fruit which is acid to taste and is used in chutneis. Chloroxylon swietenia DC. is a good timber tree. Mibrraya Koenigii Spr. is the curry-leaf tree the leaves of which are used to flavour curries. M. paniculata Jack is a garden plant commonly cultivated for its beautiful foliage and white fragrant flowers.

The large Indo-Malayan genus Citrus has several species with edible fruits of which the following are well known:

(i) C. reticulata Blanco, the Santara of Nagpur, the Kamala of E. India, the Mandarin orange or the Loose skinned orange much cultivated for the deli­cious fruits, (2) C. sinensis (L.) Osbeck, the Musambi orange, the Tight-skinned orange, (2) C. paradisi Macf.,—the Grape Fruit, (3) C. maxima (Burm.) Merrill, the Batabi Nimbu of E. India, (4) C. limettioides Tanaka, Mithanimbu or Sherbati nimbu, C. aurantifolia Swingle, the Kagzi and the Pati nimbu, etc.

The juice of these fruits is very tasteful and rich in vitamin contents. The oranges are used to prepare marmalade and the fruit-rind as well as the fruits of some species are used as pickles and chutney.

The family is closely related to Simarubaceae, Burseraceae and Meliaceae, all of them being predominantly woody, having oil glands and a disc between the androecium and gynoecium.

Wettstein considers it also allied to Terebinthaceae and includes it in his Terebinthales along with Simarubaceae, Burseraceae and Meliaceae while Hallier also includes Rutaceae in his order Teribinthenae and considers that the family has been derived from the Ranalian stock probably from Lardizabalaceae through Capparidaceae.

Family # 8. Simarubaceae:

Trees or shrubs with a bitter printiple in the back. Leaves pinnate, alternate, exstipulate; rarely leaves simple. Flowers in raceme or in cymose panicles; regular, usually unisexual in dioecious plants, or rarely bisexual, hypogynous. Sepals 3—5, rarely more, free or united, valvate or imbricate.

Petals as many as sepals, free or united, valvate or imbricate; rarely petals absent. Stamens as many as or double the number of petals in 2 series; filaments with a scale at the base; anthers bilocular, dehiscing laterally.

Carpels usually 4—5, completely united to form a syncarpous ovary or united only by the styles and stigmas, superior; ovule solitary in each carpel on mar­ginal placenta. Fruit a samara or a schizocarp or a capsule, or rarely drupaceous; seed with scanty or no endosperm; cotyledons thick.

The family consists of about 200 species under 30 genera and is distributed in the tropical and subtropical countries of the world while a few are found in temperate regions. It is represented in India by 13 species, common among them are: Ailanthus excels a Roxb., A. integrifolia Lamb., Balanites aegyptiaca (L.) Del. etc.

The family is allied to Rutaceae from which it differs in the absence of oil glands and presence of a scale at the base of a filament, the genus Balanites is segregated as a distinct family Balanitaceae by some authors. A few species belonging to this family are important for their medicinal properties, viz., Quassia amara Linn., Brucea antidysenterica Linn., Picrasma excelsa (PI.) Lindl., Simaruba amara Aubl. and Samadera indica J. Gaertn.

Ailanthus excelsa and a few other species of the genus yield soft and light timber and also have medicinal properties. Balanites aegygtiaca is the Hingul or Ingudi Briksha of Sanskrit literature, the seeds of which yield an oil.

Family # 9. Borseraceae:

Deciduous trees or shrubs. Leaves gland-dotted, exstipulate, alternate, pinnately compound. Inflorescence racemose or paniculate or rarely flowers solitary. Flowers actinomorphic, uni- or bisexual, hypogynous. Sepals 3—5, free or united at base, valvate or imbricate.

Petals 3—5, free, valvate or imbricate, rarely petals absent. A cupular or annular disc is present. Stamens as many as or double the number of petals; anthers bilocular, introrse. Ovary superior, syncarpous, 2—5-locular.; owdes 1 — 2 with ventral raphe, anatropous, on axile placentas. Fruit a drupe with 1— 5 stones, oh a capsule. Seed with a straight or curved embryo and without endosperm.

Schizogenous or lysigenous resin canals are present in the phloem. Mucilage cells occur in the upper surface of epidermis of leaves. A few genera are polygamodioecious. viz., Garuga, Commiphora, Crepidospermum, etc. Corolla is gamopetalous in Hedwigia- Amyris has monocarpellary pistil.

The family consists of 16 genera having about 600 species most of them occurring in tropical America. Common Indian plants of Burseraceae are Boswellia serrata Roxh., Bursera serrata Coleb, Garuga pinnata Roxb. Commiphora wightii (Arn.) Bhandari etc.

Burscraceae is much allied to Rutaceae from which it differs in having resin ducts in the cortex. It is also close to Simarubaceae and Meliaceae and the four families are placed in the same order by most authors. This family resembles Euphorbiaceae to some extent having ovules with ventral raphe.

The family is economically important, many species yielding fragrant resin which is burnt as frank-incense. Boswellia thtmfera Roxb. ex Flem. yields East Indian Olibamzm. Dacryodes hexandra Griseb is the source of elemi while Manila elemi is obtained from Canarium commune Linn.

Commipnora wightii yields guggul— the Indian olibanum. Guggul is also obtained from Boswellia serrata K.oxb— the Saloi tree of Peninsular India. The soft wood of this trees is used as paper pulp of news print. The inner bark of B. papyrifera separates in sheets and is used as paper. The balsam of Mmyn’f toxicofera Xinn. is poisonotis.

Family # 10. Mieliaceae:

Trees or shrubs, deciduous or evergreen. Leaves pinnate, alternate, exstipulatc. Panicles cymose, axillary. Flowers bisexual rarely anisexual, actinomorphic, hypogynous. Calyx of 4-5 free sepals, imbricate, rarely valvate; often sepals connate at base. Petals 4-5, rarely fewer or more, free or united, Imbricate, rarely valvate. Stamens 8-10, monadelphous. rarely free; anthers 2-celled, dehiscir longitudinally.

A disc is usually present between the androecium and gynoeciuni. Carpels 2-5; ovary syncarpous, superior, 2-5-celled; ovules 1-2 in each cell, rarely more, anatropous with ventral raphe, on axile placentation; style short, stigma capiiate, discoid or lobed; Fruit a berry or drupe or a capsule; seeds often winged, with or without endosperm, rarely arillate.

Melia & Toona are deciduous. Most other genera also remain leafless for a very short period. Appanamixis is evergreen. Leaves are pinnate in most genera but twice or thrice pinnate in Melia; leaflets few or many, rarely 3 or only 1. In Appanamixis the flowers are polygamodioecious and the females are in spikes or racemes.

In this genus flowers are 3-merous with 6 monadelphous stamens and 3-locular ovary. Free stamens are found in Toona and in some other genera. In most of the genera ovules are 2 or 1 in each cell of the ovary but in Sojmida, Swietenia and Toona ovules are many and the fruits are many seeded.

Seeds are winged in Toona, Sojmida, Swietenia, Khaya, etc. while Azadirachta, Melia, Carapa ,etc. have wingless seeds. The seeds in Appanamixis are arillate.

Xylocarpus has a very large globose capsule the 4 coriaceous valves of which open opposite the obliteratdd dissepiments. The Californian species Guarea ropalocarpa has leaves which behave like short branches. These are 30-40 cm long and have several leaflets which gradually unfold.

The lowest leaflets remain in the rachis for 2-3 years when apex of the rachis continues to grow. When the uppermost leaflets develop many of the lower leaflets drop off. One leaf thus remains in the tree for 10-12 years.

Stem-anatomy shows that the pericycle is composed of distinct crescent-shaped fibres which are often close to each other forming a continuous ring. Vessels are in multiples of 2-3-and the perforations are simple. There is paratracheal wood paren­chyma.

Meliaceae is a tropical family, with about 800 species under 50 genera. Swietenia a genus of timber yielding species is tropical American. Cedrela is distributed in the Old as well as the New World. In India the family is well represented. Some are suitable for comparatively dry situations while Appanamixis, Walsura etc. prefer more or less humid soil and Xylocarpus is a typically mangrove genus.

The family comprises a good number of excellent timber trees. Swietenia mahagoni Jacq. the true Mahogany and S. macrophylla King—the Honduras Mahogany are American. Khaya se- nigalensis A. Juss is the Africa.. Mahogany and is equally good. Chloroxylon swietenia DC. is thejndian Satin vjood.Chickrassia tabularis A. Juss of E. India and Burma is the Chikrasi, a tall timber tree. Cedrela odorata Linn, a valuable timber tree also yields the cedar-oil used in microscopy.

Azadirachta indica A. Juss. is the Neem tree or Margosa tree the juice of which has antiseptic properties. Margosa oil obtained from the seeds is used for burning as well as in medicine. The pulp of the fruit oi Melia azedarach is poisonous and a decoetion of the leaves is used as an insecticide. Soyrruda febrifuga A. Juss a timber tree is also medicinally important. The flowers of Chickras a yield a red dye.

Meliaceae is related to Rutaceae on one side and to Burseraceae and Simarubaceae on the other. It is included in the Geraniales by Engler for the character of the ovule which has a ventral raphe. Bessey also included it in Geraniales and considered that it originated from the Maivales, due to the presence of monadelphous stamens.

Hallier considered that Meliaceae was derived from Rutaceae and he included Meliaceae in his Terebinthales. Hutchinson places Meliaceae in an order of its own viz. Meliales which he places next to Rutales. Takhtajan includes Meliaceae in Rutales where Burseraceae and Simarubaceae are also included.

In his system of arrangement Rutales is followed by Sapindalcc. Cronquist has Meliaceae in Sapindales where in are included Burseraceae, Simarubaceae, Rutaceae, Zygophyllaceae along with Sapindaceae and other allied families.

Family # 11. Malpighiaceae:

Trees or shrubs, often scandent or lianes, often densely hairy; hairs unicellular and usually branched; in some species stinging hairs are present. Leaves glandular below or on petiole, opposite or alternate, often whorled, simple, stipulate; stipules deciduous, usually small, rarely large and opposite the leaves. Inflorescence is a simple raceme or a panicle.

Flowers bisexual or polygamous, actinomorphic or obliquely zygomorphic, hypogynous or perigynous, pentamerous; torus pyramidal or flat or slightly depressed; pedicels jointed at base and bracteolate. Sepals 5, free or connate at base, imbricate or rarely valvate, persistent, each or at least one is provided with a large gland at the base on the outer side. Petals 5, free, clawed, usually convolute in bud and imbricate.

Disc small; stamens 10 in 2 whorls obdiplostemonous, often some reduced to staminodes; filaments connate at base in a ring or short tube; anthers bilocular, introrse, with a thick connective produced at apex. Carpels 2-5, usually 3, wholly or partly coherent, often keeled; cells as many as carpels; ovary obliquely placed.

Ovule solitary in each chamber, pendulous from a long funicle, with a ventral raphe; pla­centation axile; styles distinct; stigma capitate. Fruit a schizocarp breaking into one- seeded mericarps which are winged or nut-like, rarely fruit is drupaceous. Seeds without endosperm and with a large embryo; cotyledons usually convolute, thick or leaf-like, often unequal; rarely the seed has more than one embryo.

Anomalous secondary growth occurs in most of the climbing genera, with several vascular strands without forming a ring. Vessels are in multiples of 2-3 with alternate intravascular pitting; perforations simple; wood parenchyma paratracheal. Fibres are simple pitted.

Floral formula:

Camarea a Brazilian genus has low growing shrubs with small leaves and large swollen leaves; they are xerophytic. In this genus the florwers have free carpels as are found in Gaudichaudiana, Jamesia, Aspicarpa and Schwannia. In Acmantherea and Pterundra anther loculi are winged.

In Lasiocarpus stigmas are 2-lobed and twisted. In Stigmalophyllon (Stigmaphyllon) stigmas are broad and leaf like. Brathyptens has one cotyledon aborted in the seed.

The family consists of about 800 species under 60 genera the majority being tropical American. Hiptage benghalensis Kurz (Syn, H. madablota Gaertn) is the Madha- bika or Madhabilata planted in gardens for the fragrant flowers.

Aspidopteris rotundifolia A. Juss is found in eastern parts of lndia. Malpighia glabra is much cultivated in garden as an ornamental perennial. The fruits of this species are eaten in West Indies where it is indigenous. The leaves and shoots of Banisteria caapi Spruce yields a hallucinatory drug.

Malpighiaceae has been included in Geraniales by Engler as well as by Rendlt who puts this family and Zygophyllaceae side by side. These 2 families are also placed in one order by Hutchinson, e.g. Malpighiales which according to him is a compara­tively primitive order in Lignosae while Geraniales is an advanced order in the Herbaceae.

According to him Malpighiales has been derived from Tiliales. Takhtajan includes Malpighiaceae in Geraniales where he includes Zygophyllaceae among other families. Cronquist and Heywood include Malpighiaceae in Polygalales and consider it to be associated with Trigoniaceae and Tremandraceae and also close to Humiriaceae and Zygophyllaceae.

That Malpighiaceae and Zygophyllaceae are closely allied is the opinion of most taxonomists. One genus Nitraria is intermediate between the two families and are included by some in Zygophyllaceae while in Malpighiaceae by others while Takhtajan places it in a family of its own, e.g. Nilrariaceae which he places bet­ween Malpighiaceae and Zygophyllaceae in the order Geraniales.

The family Malpighiaceae is subdivided into 2 tribes by Niedenza as noted below:

I Pyramidotorae—Receptacle pyramidal; mericarps winged.

II Planitorae—Receptacle flat or concave, mericarps not winged.

Family # 12. Polygalaceae:

Herbs, shrubs, rarely short-sized trees; few are lianes. Leaves simple, opposite or alternate, or often whorled; exstipulate or often scale-like stipules present or stipules represented by glands or spines. Inflorescence is an axillary or terminal raceme or spike or panicle, rarely flowers solitary. Flowers strongly medianly zygomorphic, bi­sexual and hypogynous, subtended by a bract and a pair of bracteoles.

Sepals 5, free, unequal, imbricate and persistent;- the 2 laterals are much larger and petaloid and usually project on each side like wings; rarely sepals united- Petals 5, usually connate at base; the anterior median petal is largest, boat shaped, lobed, fimbriated or with a crest at the apex and is termed the keel; the 2 lateral petals are often rudimentary or altogether suppressed; the petals are often adnate to the staminal tube; the margin of the petals are usually oblique or irregular.

Stamens 8, all united in a tube split on the back and united to the keel near the base, anthers 1-2-IocuIar opening by apical pores; pollen grains are ellipsoidal with a coarse pitting at the poles and longitudinal bands broken in the middle by an equatorial ring; floral anatomy reveals that originally there were 10 stamens in two 5-merous whorls and the median member of each whorl became suppressed; sometimes the reduction was carried on more in some genera so that there remained only 7, 4 or 3 stamens.

Ovary superior, of 2.united carpels, bilo­cular, with 1 anatropous ovule in each locule, pendulous from axile plancentation; style short, sometimes broadened upwards with an elbow-bend at the apex, rarely with a lateral or apical projection; stigma oblique; sometimes carpels are 3. Fruit usually a capsule, rarely nut, samara or drupe. Seed caranculate, with fleshy endosperm, rarely endosperm absent, the carancle functions as elaiosome; embryo straight.

In this family majority of the plants are shrubs or undershrub’s or herbs. Xanthophyllum has trees while Securidaca is mainly lianes. Some species of Salomonia are parasitic on roots. Epirrhizanthes has 2 species in Malaya which are saprophytes.

The flowers of Carpolobia have 5 united petals and only 5 stamens. In “this genus as well as in Trigoniastrum the ovary is tricarpellary and trilocular. Xanthophyllum has a mono­carpellary unilocular ovary; here of the 8 stamens 2 are free, other six united in a tube.

Floral formula:

Wood anatomy shows the presence of large vessels which are usually isolated; intervascular pitting alternate; perforations simple; wood parenchyma paratracheal; rays uniseriate, heterogenous, and with bordered pitted fibres.

The family consists of about 700 species in 10 genera; the genus Polygala containing more than 500 species of which 23 are Indian. The family is distributed all over the tropical and temperate zones but absent in New Zealand and Polynesia. In addition to 23 Polygala species Salonionia, Securidaca and Xanthophyllum are also found in Eastern India.

The family is not of much economic importance. Polygala senega Linn, an American plant has emetic, purgative and diuretic properties and is a reputed antidote against snake-poison. P. crotalarioides Buch.-Ham. of the Himalayas has the same properties. Xanthophyllum flavescens Roxb. is a good timber tree. Polygala venenosa is a very poisonous plant P. tinctoria and Krameria triandra are used in dyeing.

Polygalaceae has been included in Geraniales by Eugler in the suborder Polygalinae with Tremandaceae. Engler places the genus Krameria in Caesalpinioideae of Legumi­nosae suggesting that Polygalaceae might have been derived from a stock ancestral to Leguminosae. Krameria is placed in a distinct family by Hutchinson who includes Poly­galaceae and Krameriaceae in Polygalales after Violates.

Rendle places Polygalaceae after Sapindales as a family of anomalous affinity. Takhtajan also keeps Krameriaceae as distinct from Polygalaceae and includes both these families in Polygalales along with Trigoniaceae, Vochysiaceae and Tremandraceae and places Polygalales next to Gerani­ales.

According to Cronquist Polygales should include Malpighiaceae also along with Trigonaceae, Vochysiaceae and Tremandaceae and he does not separate Krameria from Polygalaceae. Heywood agrees with Takhtajan in his treatment of the order Polygalales.

Family # 13. Euphorbiaceae:

Herbs, shrubs or trees, rarely climbing or creeping; milky latex often present Leaves usually simple, alternate or opposite, stipulate or not; leaves rarely reduced to scales or spines.

Inflorescence various, a simple raceme or spike, cymose panicle or head like cluster or a cyathium—a special type of inflorescence with one female flower surrounded by many male flowers; bracts and bracteoles often present and often glan­dular.

Flowers unisexual in monoecious and dioecious plants, usually small and in­conspicuous, perianthless or with perianth, actinomorphic or very rarely zygomorphic. Perianth when present usually consisting of calyx only; rarely calyx and corolla both present, usually pentamerous, imbricate or valvate.

Disc present or absent and often represented by glands. Stamens few to very many, free or monadelphous or polyadel­phous, often stamen only one in a male flower; anthers 2-celled opening lengthwise, transversely or by apical pores.

Female flower with a superior ovary; carpels usually 3, syncarpous; ovary sessile or stipitate, usually 3-celled with 1-2 pendulous ovules; ovules anatropous, with ventral raphe, on axile placentation beneath a prominent “obturator” or placental outgrowth; styles as many as carpels, free or united below, each often 2-lobed and then with stigmas double the number of styles.

Fruit a schizocarpic capsule (regma), sometimes berry or drupaceous, or nut-like.

The large family has a wide range of variation in vegetative as well as in floral parts. There are trees, shrubs or herbs but few are climbing. Putranjiva, Bischofia Trewia, Aleurites, etc. are trees. Most of them are evergreen but Trewia is deciduous as are Anlidesma ghaesembilla Gaertn., Croton oblongifolius Roxb. etc. Tragia, Cnesmone, etc. are climbers or twiners. Tragia is hispid with stinging hairs.

Some species of Euphorbia are marked xerophytes and have a Cactus-like appearance. They have fleshly stem, cylindrical or angular, with thick succulent leaves or small scaly leaves of are leafless, thorny or unarmed.

In some species of Phyllanthus the branches are modified into flat leaf-like cladodes and the true leaves are rudimentary. Phyllanthus flutians Muell-Arg. of Brazil is the only submerged aquatic plant belonging to this family. Leaves are simple but species of Hevea and Bischofia jauanica Bl. have trifoliate leaves.

Cyathium is. a special type of inflorescence. This has a calyx-like involucre bearing large glands near the rim. A solitary female flower with only a naked, tricarpellary ovary terminates a slender peduncle surrounded by a number of male flowers.

The male flowers are like the female flower perianthless and each is represented by a single stamen. All the flowers are pedicelled and are subtended by a thin scaly bracteole. The pedicel of the female flower is much longer than those of the males and brings the flower out of the involucral cup.

The glands on the margin of the involucre are nectar- secreting. Rarely perianth is present in the form of minute scales. The involucre is urn-shaped and regular in Euphorbia but irregular and with a posterior appendage in Pedilanthes. In the genus Mono-taxis the cup-shaped involucre is replaced by a whorl of scale-­like bracts and the solitary central pistillate flower is surrounded by staminate flowers.

Perianth is present in both type of flowers, the pistillate flower being sessile while the staminate flowers are long-stalked.

Flowers are always unisexual, and plants are usually monoecious but Excoecaria, Suregada, Trewia, etc. have species which are dioecious. Corolla is usually absent but in Jatropha, Aleurites, Croton, etc. the flowers are dichlamydeous with a distinct corolla. The number of stamens vary from 1 to many.

In Euphorbia, Pedilanthtis, etc. the male flower has a single stamen. In Breynia, Phyllanthus, etc. there are 3 stamens, monadelphous, forming a central column. In Baccauria stamens are free.

In Manihot, Jatropha, Chtozophora, etc. stamens are in more than 1 whorl. In Trewia, Mallotus etc. numerous free stamens are crowded on a flat or convex receptacle. In Homonoia and Ricinus the filaments of stamenis are repeatedly branched.

According to Pijl the so called male flower of Ricinus is in reality an inflorescence, a condensed panicle, consisting of numerous male flowers each of which is reduced to a single stamen only. This view has been supported by Eames.

In most genera carpels are 3; Mercurialis usually has a bicarpellate bilocular ovary while in Antidesma, Drypetes and a few other genera the ovary is unilocular by abortion. Hura has a multicarpellate multilocular ovary, the number of carpels being as many as 15.

In Glochidion the number of carpels vary from 2-15. Styles free or connate near base in most cases but in Endospermum they are completely united forming a flat spreading disc. Fruits are schizocarpic capsule in most cases; in Putranjiva, Emblica, Aleurites and a few other genera they are drupes while in Bischofia the fruit is a berry.

Floral formula for Eupharbiaceae may be expressed as:

Anatomical characters also vary in different genera. In the stem pericycle occurs as isolated strands of fibres or as a continuous mechanical ring. The pericycle fibres occur in groups in some genera and also singly. Vessels have simple or scalariform perforations or both.

Wood parenchyma occur as scattered cells, in uniseriate bands or apotracheal cells. Fibres are thick-walled and simple-pitted and often septate. Intraxylary phloem is present in the stem of some genera. Cambiform tissue occurs as. isolated patches or as continuous sheath. Latex vessels are segmented or un-segmented and branched.

The family consists of about 300 genera and over 6000 species, the genus Euphorbia having about 2000 species. Throughout tropical and temperate zones of both the hemis­pheres the family is distributed. Many are xerophytes and are found in arid regions of Africa, W. Asia and Australia, and almost all the members of the group Stenolobeae are Australian.

Tropical America is very rich in plants of this family and in Brazil is found the only aquatic submerged plant, viz. Phyllanthas flutians Muell-Arg. Excoecaria agallocha Linn, is a halophyte occurring in the littoral forest of India and E. Asia.

In India the family is represented by about 500 species most common of them are: Jatropha curcas Linn., J. gossypifolia Linn., Chrozophora rottleri Juss & Spr., Acalypha indica Linn. Ricinus communis Linn., Targia involucrata Linn. (Stinging Nettle), Putranjiva roxburghii Wall., Trewia nudifora Linn., Euphorbia neriifolia Linn., E. antiquorum Linn., E. pilulifera Linn., E. dracunculoides Lamk., Emblica officinalis Gaertn., Phyllanthus fraternus Web., P. simplex Retz., etc.

The family contains a number of useful plants. The most important is the Para- rubber plant of Brazil Hevea brasiliensis (H. B. K.) Muell-Arg. which is cultivated in India, Ceylon, Malaya and many other countries. Manihot glaziovii Muell-Arg. also indigenous to S. America yields ceara-rubber and is cultivated in many tropical countries.

Manihot escuenta Crantz. yields Cassava or Tapioca starch from the tuberous roots. Ricinus communis Linn, yields castor oil from the seeds used as a lubricating agent, as purgative and also for burning.

Aleurites moluccana Willd. is the source of Tung oil much used in paints and varnish and for manufacture of oil-cloth. Sapium sebiferum Roxb. is the Chinese Tallow tree found wild in many parts of India, yields an oil used in soap-manufacture, and a black or purple dye is obtained from the leaves.

Mallotus philippinensis Muell-Arg. yields a red dye from the gnandular hairs. Oil obtained from the seeds of Jatropha curcas Linn, and Croton tiglium Linn, are strong purgative.

Fruit of Emblica officinalis Gaertn is pickled and is much used in Kabiraji and Unani medi­cine. Species of the African genus Ricinodendron are good timber trees and are known as African Oaks. The latex of many species are poisonous and that of Toxicodendron species of S. Africa are strongly so.

The family was included in Geraniales by Engler particularly on the character of ovule which has a ventral raphe. It resembles Geraniaceae and allied families in the character of the fruit. It has much in common with Sterculiaceae, e.g. the monadelphous or polyadelphous stamens, presence of androphore and gynophore in some cases.

Presence of schizocarpic capsule and carunculate seeds in some members of Sterculiaceae speaks also of the close relation between the two families.

Rendle placed Euphorbiaceae under a small order Tricoccae in between Malvales and Geraniales recognising the affinity of the order with Ma vales and Geraniales-Hutchinson places Euphorbiales with single family Euphorbiaceae nearer to Tiliales, Malvales and Malpighiales in his Lignosae while Geraniales is a much advanced order in Herbaceae.

Takhtajan also recognises the affinity of Euphorbiaceae with Sterculiaceae and in his system of arrange­ment places Euphorbiales just after Malvales in the subclass Dilleniidae while Geraniales is included in subclass Rosidae.

Cronquist considers that Euphorbiales is closer to Sapindales as well as to Geraniales, Linales and Polygalales all having been derived from Rosaceous stock while Malvales has been derived from Dilleniales through Theales and not much close to Euphorbiales.

The family has been divided by Pax in the following manner:

Group A. PLATYLOBAE:

Cotyledons much broader than radicle.

Sub f. I Phyllanthoideae: Ovules 2 in each cell; latex absent.

Tribe 1. Phyllantheae—Calyx of ♂ fl. imbricate.

Tribe 2. Brideleae —Calyx of ♂ fl. valvate.

Sub f. II Euphorbioideae: (Ctotonoideae) Ovule 1 in each cell; latex present.

Tribe 1; Crotoneae—Stamens bent inwards in bud.

Tribe 2.- Acalypheae—Stamens erect in bud; fls. usually apetalous; ♂ calyx val­vate; infl. a raceme, spike or panicle.

Tribe 3. Jatropheae—Stamens erect in bud; petals present, J calyx imbricate; infl. a dichasial thyrsus.

Tribe 4. Adrianeae—Stamens erect in bud; ♂ calyx imbricate; infl. terminal spike or raceme; petals absent.

Tribe 5. Clutieae—Stamens erect in bud; sepals imbricate; petals present in ♂ fls; infl. cymose or fls. in clusters.

Tribe 6. Gelonieae—Stamens erect in bud; petals absent; ♂ sepals imbricate; infl. leaf-opposed.

Tribe 7. Hippomaneae—Stamens erect in bud; petals absent; inflorescence spicate.

Tribe 8. Euphorbieae—Inflorescence a cyatheum.

Group B. STENOLOBAE: Cotyledons as broad as radicle.

Sub f. I Porantheroideae: Ovules 2 per locule; latex absent.

Sub f. II Ricinocarpoideae: Ovule 1 per locule; latex present.

Radcliff-Smith (Heywood’s Fl. PI. of the World) divides the family into following 8 tribes:—Phyllantheae, Bridelieae, Crotoneae, Acalypheae, Ricineae, Jatropheae, Suregadeae and Euphorbieae.

Recent workers are in favour of slightly altering the conscription of the family Euphorbiaceae so that the following genera are now excluded from this family, viz., Androstachys, Anlidesma, Bischofia, Centroplacus, Galcerea, Hymenocardia, Microdesmis, Pera and Upaca.

In the old classification of Bentham and Hooker the family Buxaceae was included in Euphorbiaceae but Engler separated it as distinct on account of the ovules having a dorsal raphe.

Family # 14. Buxaceae:

Evergreen shrubs or trees, very rarely herbaceous (Pachysartdra). Leaves coriaceous, opposite or alternate, simple, exstipulate. Inflorescence spikate, elongated or head-like.

Flowers unisexual, in monoecious or dioecious plants, rarely flowers bisexual; actinomorphic, with or without perianth; female flowers often solitary or in lax racemes. Male flowers with one whorl of calycine perianth; sepals usually 4, connate at base.

Stamens 4 — 6, rarely more; anther bilocular, dehiscing by valves or longitudinal slits. Pistillode often present. Female flowers larger than males with one or two whorls of perianth, or without perianth.

Ovary tricarpellary syncarpous, superior, trilocular, with 2 ovules in each locule; ovules anatropous with dorsal raphe; carpels often 2 or 4; styles as many as carpels, each often bifurcate. Fruit capsular or berry-like. Seeds black and shining, endospermic, usually carunculate; embryo straight.

Buxaceae is a comparatively small family consisting of about 100 species under 6 genera but widely distributed in the tropical parts of both the worlds and extending to temperate region. Buxus wallichiana Bail, and Sarcococca pruniformis Lindl. are Hima­layan species.

Buxaceae is closely allied to Euphorbiaceae where it was formerly included. Engler treated this as a distinct family due to the presence of dorsal raphe and absence of milky sap. He included the new family in Sapindales while Euphorbiaceae was placed by him in Geraniales.

Subsequent authors support Engler in segregating Buxaceae as a distinct family but they recognise the close relationship of Buxaceae with Euphor­biaceae and consequently place the two families in the same order Euphorbiales. Buxus semprevirens Linn, is an ornamental hedge plant. It is a small tree the wood of which is good for engraving and carving. Otherwise, the family is not economically important.