Classification of Ebenales: 2 Families| Dicotyledonae

In this article we will discuss about the classification of Ebenales. According to Hutchinson, Ebenales consists of two families:- 1. Sapotaceae 2. Ebenaceae.

Family # 1. Sapotaceae:

Sapotaceae are trees or shrubs with milky latex; younger parts tomentose. Leaves are simple, alter­nate or opposite, entire, coriaceous, usually exstipulate. Inflorescence an axillary or extra-axillary cyme, often in false umbel or flowers solitary.

Flowers are small, regular, bisexual and hypogynous. Sepals 4-12 in one or 2 whorls, free or united at base, persis­tent, imbricate. Petals as many as sepals, in one or 2 whorls, united to form a rotate or urceolate or more or less funnel-shaped corolla, imbricate or contorted, often with d6rsal appendages.

Stamens in 2-3 whorls of 4-5 in each, the inner whorl fertile, the outer whorls usually reduced to staminodes, or only one whorl of fertile stamens with­out the whorls of staminodes, epipetalous; anthers 2-locular, introrse, dehiscing longi­tudinally.

Carpels 4-5, syncarpous forming a superior 4-5-celled ovary; style one, with a small capitate stigma; ovule one in each cell of ovary, anatropous, ascending with a downward micro Pyle, and with one integument. Fruit a berry or rarely 1-seeded and drupe-like; seed with a hard shining testa and broad hilum; endosperm oily or absent.

Floral formula is represented as:

In this family there is much difference in the number of perianth segments, in Madhuca sepals are 4 in 2 whorls, in Sarcosperma and Pouteria there are 5 sepals in one whorl. Sideroxylon flower is also pentamerous where as in Palaquium and Manilkara it is 3-merous.

Corolla is caducous in many genera, e.g. Madhuca, Mimusops, etc. The petals in Mimusops have a pair of appendages and the corolla appears to be 2-seriate with altogether 18-24 lobes.

The family contains about 600 species under 40 genera found in the tropical coun­tries of the world. The family is represented in India by several species in the plains, the common species are Mimusops elengi Linn. Sideroxylon tomentosum Roxb. Madhuca indica Gemel. etc. Manilkara achras (Mill) Fosb. is much cultivated for the edible fruits.

The family is divided into 2 tribes:

I. Palaquieae:

Corolla-lobes without appendage.

II. Mimusopeae:

Corolla-lobes with a dorsal appendage. Sapotaceae is closely allied to Ebenaceae and these 2 families are included in the same order by almost all workers. It is also related to Styracaceae, Symplocaceae and Lissocarpaceae although according Hutchinson these 3 families are not at all close to Sapotaceae and Ebenaceae.

Hallier placed the family Sapotaceae in a monotypic order Sapotales while Ebenaceae was included by him in Santalales. However he considered Sapotales and Santalales originated from the same ancestral stock, i.e. Linaceae and therefore the families included in these 2 orders were related to each other to some extent.

Many plants of this family are important being useful in different ways. Manilkara achras (Mill.) Fosb. is famous for the Sapodilla-fruits, original of Mexico is now culti­vated in almost all tropical countries.

This tree is also the source of chewing gum obtained from the milky juice. Vittelaria mammosa Radlk f. and Chrysophyllum cainito Linn also produce edible fruits. Madhuca butyracea (Roxb) Macbride yields vegetable butter from the kernel of the seeds.

Madhuca indica Gmel is the Mohua tree the seeds of which also yield edible oil. Gutta-percha of commerce is obtained from the Malayan trtt Palaquium gutta (Hk. f.) Baill. Mimusops elengi Linn, is tta Bakul tree an avenue tree with flagrant flowers.

Family # 2. Ebenaceae:

Ebenaceae are trees or shrubs, usually evergreen. Leaves are simple, alternate, or rarely opposite or whorled, entire, exstipulate, coriaceous. Inflorescence cymose, axillary, or flowers solitary, bracteate; pedicels absent or short and articulate.

Flowers are unisexual and usually dioecious, actinomorphic, rarely bisexual and polygamous, hypogynous, 3-7-merous. Calyx of 3-7-united sepals, usually accrescent; lobes valvate, imbricate or contorted. Petals as many as sepals united to form a tubular, campanulate, urceolate or more or less funnel-shaped corolla, lobes usually contorted.

Stamens in male and hermaphrodite flowers in one or more whorls, as many as petals in each whorl, epi­petalous; filaments short, free from each other or variously connate below; anthers bilocular, longer than filaments, introrse, dehiscing longitudinally or rarely by apical slits; connective often apiculate, rudimentary ovary rarely present in male flowers.

In female flowers staminodes often present. Carpels 2-8, united to form a 2-16-celled superior ovary in a female or hermaphrodite flower; development of false septa usually occurs, septa often incomplete above and the ovary is imperfectly septate; styles 2-8, free or united below; stigmas lobed or not; ovules 1-2 in each cell of ovary, anatropous and with 2 integuments, pendulous.

Fruit a berry with a few seeds often with a coriaceous epicarp. Seeds pendulous, usually oblong, with a thin testa and with 2-3 longi­tudinal furrows; embryo straight; endosperm copious, cartilaginous or ruminate.

Formula for a bisexual flower may be represented as:

The family comprises about 325 species in 5 genera which are restricted to the tropical region of the Old World. In India the family is represented by-several species of Diospyros and a few species of Maba. D. peregrina (Gaertn) Gurke, D. cordifolia Roxb., D. tomentosa Roxb. etc. are quite common.

The family is closey related to Sapotaceae from which it can be distinguished by the unisexual flowers and septate ovary. The 2 families are placed in the same order by most taxonomists. Hutchinson includes Sarcospermaceae, Ebenaceae and Sapotaceae in Ebenales while others favour the inclusion of Symplocaceae and Styracaceae also in Ebenales. Eben­aceae is allied to these 2 families in some respects.

The family includes several good timber trees, the most important of which is the Ebony—Diospyros ebenum Koen. the natural colour of the wood of which is black and takes high polish. D. tamentosa Roxb. and D. melanoxylon Roxb. also yield good timber similar to ebony.

The tender leaves of D. melanoxylon are used as wrapping paper for country-made cigarettes (bidi) in India. D. kaki Linn. f. is the persimmon and is available in eastern India, China and Japan. D. virginiana Linn, also yields good fruit which is known as American persimmon.

D. discolor Wild of the Philippines also produce sweet delicious fruits. D. peregrina (Gaertn.) Gurke common in the plains of India yields a hard dur­able timber and mucilaginous fruits which are used for caulking boats and waterproofing the threads for preparing fishermen’s net.