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In this article we will discuss about the classification of Caryophyllidae:- 1. Chenopodiaceae 2. Polygonaceae 3. Cactaceae.
Family # 1. Chenopodiaceae:
Salient Features of Chenopodiaceae:
Animal or perennial herbs and shrubs of xerophytic and halophytic habitats, stem jointed, flowers small, green, usually inconspicuous, corolla absent, fruit indehiseent nutlet, embryo curved, betalins present, importants plants are Beet, Spinach and Russian thisle etc.
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Chenopodiaceae is a family of flowering plants with 102 genera and 1400 species widely recognized in most plant classifications (Cronquist also). The APG System 1998, 2003 included it in Amaranthaceae on the basis of evidence from molecular phylogenies.
Some Classifications now treat this family as Amaranthaceae subfamily Chenopodioideae, with the exception of a smaller number of genera which are now included in subfamilies Salicornioideae and Salsoloideae.
Vegetative Characters of Chenopodiaceae:
Generally herbs or some shrubs but rarely trees or lianas. Salicornia Shows cactus like habit.
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Stem generally succulent or non-succulent. Annual, biennial or perennial with basal aggregation of leaves or neither basal or terminal aggregation of leaves. Erect, few are climbing.
Leaves:
Minute to large may be well developed or much reduced, even absent. Alternate or opposite, when alternate they are spiral or distichous, herbaceous or fleshy.
Sometimes membranous, petiolate or sessile, when opposite they may form connate cupules at the internodes of succulent stems. Sheathing or non-sheathing base, epulvinate, exstipulate, Lamina entire or dissected, unicostate reticulate leaf shape may be hastate, sagittate. Base is attenuate or cuneate.
Floral Characters of Chenopodiaceae:
Plants generally hermaphrodite, sometimes monoecious or andromonoecious, rarely gynomonoecious or dioecious or polygamomonoecious.
Inflorescence:
Solitary, axillary or aggregated as cyme, sometimes paired. In Sarcobatus two male inflorescences are catkin.
Flower:
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Minute or small, regular cyclic, bisexual Bi or tricyclic, free hypanthium present (the stamen is inserted on a disc on calyx) or absent, Hypogynous.
Perianth:
5 sepaline or vestigial or absent, imbricate, fleshy or non-fleshy, persistent, accrescent or non-accrescent, gamophyllous. In Salsola polyphyllous. Commonly becoming appeandaged with spines, wings or tubercles.
Androecium:
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3-5 free or adnate to perianth lobes, antiphyllous, anthers bent inwards in bud, dehiscing longitudinally.
Gynoecium:
2-5 carpels, Pistil one celled, Syncarpous, Superior rarely partly inferior. Pendulous ovule on basal placentation.
Endosperm haustoria may be present.
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Fruit:
Non-fleshy nut or utricle enclosed in fleshy hypanthium.
Seed:
Non-endospermic, Perisperm present rarly absent. Cotyledons two, embryo chlorophyllous, curved achlorophyllous embryo in Atriplex, Chenopodium.
Economic Importance of Chenopodiaceae:
Food:
1. Beta Vulgaris: Beet root, beet sugar is obtained form it. It is a good medicine in anaemia also.
2. Spinacia oleracea: (Spinach, Palak) The leaves are rich is Vitamin B and iron etc.
3. Chenopodium album: (Bathua): Green herb is eaten.
4. Basella rubra: (Khatta patta): Leaves used as vegetable and for pakora.
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Medicine:
1. Chenopodium anthelminticum: Seed oil as verunifuge.
2. Kochia indica: Cardiac stimulant
3. Arthrocnemum indicum: Antidote for Scorpion sting.
4. Spinacea oleracea: Leaves laxative.
Forage:
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Many members are non-poisonous forage and fodder
Kochia indica (Bui) — forage.
Salsola baryosma (Loonuk) — Fodder Atriplex (Chalwat): fodder.
Chenopodium murale (Khartua)—Fodder.
Sueda fruiticosa (Lunak)-Fodder
Other uses:
Kochia scoparia: Ornemental
Kochia trichophyla: Ornemental
Salsola foetida: Dye is obtained
Classification:
Kingdom: Plantae
Unranked: Angiosperm
Unranked: Eudicots
Unranked: Core eudicots
Order: Caryophyllales
Family: Chenopodiaceae (Amaranthaceae).
Sarcobatus has long been acknowledged as an anomalous member by Bentham and Hooker in 1880. He has put it as a monogeneric tribe. Behnke (1997) Proposes reaising it to family rank, because sieve element plastid form supports recent chloroplast DNA sequencing studies in portraying it nearer to Phytlolaccaceae than Chenopodiaceae.
He provides no organized comparative descriptive data, merely a short Latin diagnosis of the new family, on the basis of which Sarcobatus is incompletely separable morphologically from the description of Chenopodiaceae.
Family # 2. Polygonaceae:
Salient Features of Polygonaceae:
It is a family of flowering plants also known as knotweed family or Smartweed family. The name was given on the genus name Polygonum (knotweed). The family is named for the many swollen node joints that some species have poly=many, goni- knee or joint. The Other important plants of this family are Fagopyrum (buckwheat), Rumax (Sorrel), Rheum (Rhubarb) etc.
The family consists of 43 genera and 1100 species, among which some important genera are:
Polygonum (200 species)
Rumex (200 species)
Cocoloba (120 species)
Eriogonum (250 species)
Calligonum (80 species)
The members are distributed in tropical and temperate countries. In India, Antigonon leptopus (climber), Calligonum polygonoides. (wild in Punjab), Cocolaba uvifera (garden plant), Fagopyrum (Himalaya), Muehlenbeckia (xerophytic, phylloclade, ornamenta), Polygonum (everywhere), Rheum (Himalaya), Rumex (wild) are found.
Vegetative Characters of Polygonaceae:
The stem is aerial, erect or prostrate (Polygonum plebejum), flat (Cocoloba platyclada or Muehlanbeckia platyclada), angular, cylindrical, branched, swollen nodes.
Leaves:
Simple, alternate opposite in Pterostegia, exstipulate in Exogoneae sheathing stipules known as ochreate, Radicle (young Rurnax), Cauline and Ramal, petiolate, size may be minute or large, absent in Muehlenbeckia, glossy red veined in Cocoloba uvifera.
Floral Characters of Polygonaceae:
Inflorescence:
Flowers solitary axillary, often in fascicles, Raceme (Antigonon), dense raceme (Cocolaba uvifera), spike (Polygonum), cyme, (Chorizantha), umbel (Eriogonum), solitary axillary (Polygonum plebejum), Capitate cyme (Fagopyrum) with or without involucral bracts often conspicuously ochreate. Anemophily or Entemophily.
Flower:
Small, regular, 2, 3 or 5 merous, cyclic to partially acyclic, free hypanthium present or absent, hypogynous, Bracteate, Ebracteate, pedicillate, Bisexual or unisexual (Rumex, Muchlenbeckia), flowers inconspicuous (Rumex) or showy and distinct (Antigonon).
Perianth:
Ambiguously with distinct calyx and corolla, or sepaline or petaline, 2-6 free or jointed, 1-2 whorl (spiral) when biseriate, similar in two whorls, or different in two whorls, fleshy or non-fleshy, persistent, 3+3 homochlamydous e.g.,
Rumex:
Outer lobes small & reflexed, inner lobes winged, surrounds the fruit, free or connate at the base.
Antigonon:
5 coloured perianth lobes in 2 series.
Muehlenbeckia:
Outer 3 lobes out of 5 are thick and succulent.
Oxyria:
2 perianth lobes.
Koenigia:
3 lobes.
Polygonum:
5 lobes, 3 outer whorl and 2 in inner whorl. Anterior inner perianth lobe is suppressed, outer 3 are persistent and form wings enveloping the fruit.
Polygonum tinctorium:
4 lobes, 2+2
Androecium:
6 stamen, 8 in Fagopyrum, Antigonon, Muehlenbeckia, Cocoloba, 3-9 in Polygonum, 9 in Rheum, Erigonum, free, antitepalous, Oxyria (2), Rumex (6) in 3 pairs. In Polygonum stamen of outer series are double and in Rumex stamen of inner series are suppressed (usually 3+3). Anthers dorsifixed or basifixed, versatile, introse or extorse, dehiscing by longitudinal slits.
Gynoecium:
2-4 syncarpous, superior, ovary unilocular, 2 in Polygonum orientale, 3 in Rumex, basal placentation, style 2-4,
Fruit:
Trigonous achene, nut enclosed in fleshy hypanthium.
Seed:
Endospermic, endosperm ruminate (Cocoloba) or non-ruminate, perisperm present or absent,
Economic Importance of Polygonaceae:
1. Calligonum: Flower rich is protein.
2. Antigonon leptopus (Coral creeper): Woody ornamental climber.
3. Cocoloba uvifera: Flower astringent.
4. Rheum emodi: Laxative roots.
5. Oxyria digyna (Ambu): Medicinal plant as cooling substance.
6. Rumex crispus (Chukkah): Leaves vegetable.
7. Rumex hastatus (Bhilmora): Leaves condiments.
8. Fagopynum cymosum (Buckwheat): Leaves vegetable.
9. Fagopyrum tataricum (Paphra): Grains as food.
10. Polygonum chinense (Ameta): Ornamental.
11. Polygonum plebejum (Raniphul): Roots medicinal.
12. Polygonum fagopyrum (Kutu) Buckwheat: Grains as food.
13. Polygonum alpinum: Ornamental.
14. Cocolaba platyclada: Ornamental.
15. Muehlenbeckia: Ornamental.
16. Polygonum glabrum: Ornamental.
17. Polygonum orientale: Ornamental.
Systematics:
The family is well defined and is universally recognized, but its position has been less clear. The family is related to Chenopodiaceae, Amaranthaceae and Nyctaginaceae in vegetative and floral characters. It differs in possessing ochreate stipules and trigonous ovary. It recembles Urticaceae is possessing single orthotropus ovule.
In Cronquist system it was given its own order i.e., Polygonales, but in APG system it was a part of Caryophyllales. Previously Polygonaceae was divided into 3 subfamilies.
Subfamily 1. Rumocoideae:
Cyclic flowers, non-ruminate endosperm.
Tribe 1. Eriogoneae: Ochreate stipule absent e.g., Eriogounm.
Tribe 2. Rumiceae: Ochreate stipules present e.g. Rumex.
Subfamily 2. Polygonoideae:
Flowers acyclic, endosperm nonruminate.
Tribe 3. Atroplexideae: Shrubs – Calligonum.
Tribe 4. Polygonae: Herbs – Polygonum.
Subfamily 3. Cocoloboideae: Ruminate endospen.
Tribe 5. Cocoloboidae: Bisexual flower – Cocoloba.
Tribe 6. Triplaridae: Unisexual flower – Triplaris.
According to new system Polygonaceae is divided into two subfamilies.
1. Polygonoideae:
With 28 genera and 800 species characterized by lack of involucre and presence of ocreae. e.g., Polygonum, Rumex, Calligonum.
2. Eriogonoideae:
With 15 genera, 330 species, exclusive to New world, cymose inflorescence and lack of ocreae. e.g. Eriogonum.
Classification:
According to Cronquist
Subclass: Caryophyllidae.
Order: Polygonales
Family: Polygonaceae.
According APG III Systems:
Unranked: Core angiosperm
Unranked: Core Eudicots
Super order: Caryophyllanae
Order: Caryophyllales
Family: Polygonaceae.
Family # 3. Cactaceae:
Salient Features of Cactaceae:
Cactus is a member of the family Cactaceae, native of America except Rhipsalis bacccifera which is native of old world. These are ornamental plants. Some plants are crop plants for fodder, fora, fruits, cochineal and other uses. Numerous species have been used since ancient time by indigenous people for their psychedelic effects. Cacti are part of the order caryophyllales.
Cacti are unusual and distinctive plants, adapted to extremely arid or semi- arid hot environments, as well as tropical environment as epiphytes or hemi epiphytes. They show a wide range of anatomical or physiological features which conserve water. The stem is adapted to become photosynthetic and succulent while the leaves have become the spines for which cacti are well known.
Tallest cactus is Pachycereus pringlei with 19.2m height and smallest is Blossfeldia liliputiana only 1 cm diameter at malurity. Flowers of Cactus are large and like the spines and branches arise from areoles. The life of a cactus is as long as 300 years and as short as 25 years.
Saguaro cactus (Carnegiea gigantea) grows upto 15 meter—17.67 cm in height but in its first ten years, it grows only 10 cm. The “mother in law’s cushion” (Echinocactus grusonii) reaches a height of 2.5 m. and a diameter of lm. and flower once in 6 years. The diameter of flower ranges from 5 to 30 cm, and colours are conspicuous and spectacular.
Vegetative Characters of Cactaceae:
Cacti are perennial and grow as trees, shrubs or vines. Mostly they are terrestrial, but some are epiphytic e.g., some members of Rhipsalideae and Hylocereeae. Plants are fleshy, herbaceous or woody with single stem.
Many forms are branched tree like except in leafy genera like Pereskia. The function ofcarbon assimitation is carried out by the simple or branched flattend columar stem, the phylloclade. Photosynthetic surface is increased by the development of tubercles.
One of the interesting features is the presence of clusters of spines which are borne upon the tubercle and show a great variety in size and form. The spine bearing area is called areole. The spines of an areole are often radiating with the central porrect (i.e. standing perpendicular to the surface of flattened stem).
There have been various interpretatios regarding the morphology of tubercle and spine. However, the developmental study shows that the lateral shoot originates soon after on the leaf base. Then the leaf base and axillary shoot together form a tubercle. Spines correspond to the leaves and are borne dorsiventrally at the growing points of the lateral shoots.
The presence of transitional structure between leaf and spine is found in Opuntia and Echinops etc., indicate the leafy nature of spines. Slender bristles are also present in Opuntia in addition to the spines called Glochidia, which are homologous to spines. In Mammillaria, Cerus etc. Nector secreting glands are present among the spines.
They are considered to be metamorphosed spines. The function of spines is protection. It reduces the rate of transpiration and also acts as a screen protecting the underlined tissue from sunlight. Pereskia has alternate simple broad and fleshy leaves. In Opuntia narrow fleshy leaves are also present. Some times on early stages in other genera the leaves are very small scale like and not well developed.
The anatomy also shows xerophytic characters. Epidermis has a thick cuticle, sunken stomata followed by collenchymatous hypodermis below this the photosynthetic region with chlorenchyma is present.
The cortex and pith are well developed, consisting of long pitted water storage cells often centaining mucilage. Since the tissues of cacti retain capacity for growth for a long time, plant can be reproduced vegitalively and can be grafted on the stem of other species.
Adaptations for xeric conditions:
The plants inhabit the xeric condition, as they may be succulent, with thick or reduced succulant leaves, (Except Pereskia). Some cacti develop ephemeral ordeciduous leaves (Opuntia ficus-indica or prickly pear). The leaves modify into spines to reduce transpiration and defend themselves from water seeking animals.
Pereskia is determined to be ancestral genus of all cacti. Their enlarged stems carry out photosynthesis and store water. Unlike many other succulents, the stem is the only part of a true cactus where it takes place. The have waxy coatings also.
The bodies of many cacti have become thickened during the course of evolution, and form water retentive tissue and in many cases assume the optimal shape of a sphere or cylinder.
By reducing its surface area, the body of the plant is also protected against excessive sunlight. Most cacti have a short growing season and long dormancy. A fully grown Saguaro cactus can absorb upto 3000 liter of water in ten days. This is helped by the ability to form new roots quickly.
Two hours after rain following a relatively long drought, root formation begins in response to the moisture. An extensively ramified root system is formed spreading out immediately beneath the surface. The salt concentration in the root cells is relatively high so that water can be absorbed immediately in largest possible quantity.
The cacti have very shallow roots that can spread widely close to the surface of the ground to collect water. A young saguaro only 12 cm tall has a root system covering on area of 2 meter in diameter but with no roots more than 10 cm deep. The plants show CAM photosynthesis.
Floral Characters of Cactaceae:
Inflorescence:
Flowers are produced during or at the end of the rainy season. The majority of the genera have solitary flowers arising from the areoles. In Rhipsalis sp. several flowers develop successively from the aerole. In Pereskia the flowers are borne on terminal panicles arising in the axils of upper leaves. Pollination entomophilous.
Flower:
Actinomorphic or Zygomorphic by curving of perianth, stamen and pistil. An extreme is seem in Epiphyllum where flowers are bilipped, bisexual rarely unisexual and epigynous. Partially acyclic. Free hypanthium is present.
Perianth:
Sequentially intergrading from sepals to petals or petaline, 20- 100- indefinite, free or connate basally, green or white or cream, yellow, orange, red, pink or purple.
Androecium:
15- many stamen, branched or unbranched, maturing centrifugally, free or adnate to perianth tube, polyandrous or coherent, sometimes fascicled, Anther dithecous introrse, dehiscing longitudinally.
Gynoecium:
3- many, unilocular, syncarpous, inferior, in Pereskia 2-15 syncarpous and superior, unilocular, no. of locules may increase due to false septa. Parietal placentation, style one, ovule amatropous or campylotropous. Bitegmic and Crassinucellate.
Fruit:
Fleshy or non-fleshy, capsule or berry (mostly).
Seed:
Non-endospermic, perisperm present or absent. Seeds winged or wingless.
Economic Importance of Cactaceae:
Cacti are cultivated by people worldwide, as potted plants, house plants or in ornamental garden in warmer climate. They are glass house plants.
Opuntia dillini:
(Nagphani) fruits edible and medicinal also, fruits used in gonorrhoea, stem in whooping cough, Latex as purgative, plant is antidote in snakebite.
Cereus grandiflorus:
Tall ornamental cactus, flowers open in night. Stem is given in dropsy and cardiac affection.
Pereskia aculeata:
Woody vine with edible fruits.
Nopalea cochinellifera:
Scarlet dye called cochineal, prepared from the cochineal insects which feed upon this plant.
Systematics:
Tyagi 1954, 58, 65 studied the floral anatomy of a number of members of this family on the basis of anatomical evidence he has shown that the inferior ovary in the family is resulted from an investigation of the stalk of receptacle followed by fusion of overy wall within the receptacular cup. The affinity of this family is very doubtful.
Engler placed it in opuntiales. Considered it to have been derived from parietales. Berry, Hutchinsan placed it near Cucurbitacae on the basis of evidence from embryology, floral morphology and anatomy. Wettstein, Martin, Maheshwari etc. suggested its position near or within Centrospermae.
Classification:
According to APG II System:
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Kingdom: Plantae
Unranked: Angiosperm
Unranked: Eudicots
Unranked: Core eudicots
Order: Caryophyllales
Family: Cactaceae
According to APG III System:
Unranked: Core angiospenm
Unranked: Core eudicots
Superorder: Caryophyllanae.
Order: Caryophyllales
According to Cronquist:
Subclass: Caryophyllidae
Oder: Caryophyllales
Family: Cactaceae.
