मलवासिए

 12. MALVACEAE

Distribution: The family comprises 197 genera and about 2865 species spread over tropical and subtropical regions of the world. Some 22 general and 110 species are found in India. Common forms in the country are Hibiscus, Malva, Althaea, Gossypium, Abutilon, Sida, Malachra, Malvastrum etc. Hibiscus (300 species) and Sida (200 species) are some large genera. Salient feature: Protandrous flowers; leaves with alternate arrangement; flowers are hypogynous with epicalyx; androecium shows monoadelphous condition; placentation is axile. Description: Vegetative characters of the family shows thatplants are mainly herbs rarely shrubs (Hibiscus) or woody trees (Kydia and Thespesia). Stem is erect, jointed, cylindrical, branched, solid and hairy. Flowers are mostly protandrous and insect pollinated. Seeds are dispersed by air (gossypium), animals (abutilon) or water. Leaves: Leaves are alternate, stipulate simple with multicostate reticulate venation. Stipules are free and often caducous. Inflorescence:Flowers may be solitary axillary (Hibiscus) or terminal or in some cases set in racemose or cymose inflorescence. Flowers:Bracteate, bracteolate, pedicellate, complete, hermaphrodite, actinomorphic hypogynous and pentamerous. Epicalyx may be present 3-8 in number or absent (Sida). Calyx: Consists of 5, free or connate sepals with valvate aestivation. Corolla: Corolla consists of 5 petals, often large and showy, free or basically with staminal column and with twisted or imbricate aestivation. Androecium: Consists of numerous stamens, monoadelphous, all of them being United below into a tube and the upper parts of the filaments remaining distinct. Anthers are transversally attached to the filaments, monothecous, reniform, extrorse and dehiscing by longitudinal slits. Pollen grains are characteristically spiny. Gynoecium: Consists of 5 to many fused carpels (syncarpous). ovaryis superior , multilocular, with axile presentation. Style is connate below or throughout its length and passes through the staminal tube but branches terminally. Stigmas are free and their number corresponds to the number of carpels often velvety. Although the number of carpels in most genera is 5, these are only 1 or 2 in Plagianthus, while 8 to 10 in Malvastrum, 15 to 20 in Malwa and numerous in Malope trifida. In M. trifida, carpels are arranged vertically on an elongated thalamus. Numbers of Style branches are double the number of carpels in Urena, Pavonia and Malachra.

11Fruit: fruits show variation, e.g. Loculicidal capsule in Hibiscus and Gossipium, schizocarpic

in Malva or fleshy berry in Malvaviscus. Carpels commonly separate into mericarps.

Seeds:Seeds are usually with endosperm and folded cotyledons and reniform or ovovoid.

Floral formula: Br

Epi 3-8K (5)C5A(∞)G (5)

Hibiscus sp.

Floral diagram:

Malvaspp.

Economic Importance

1. Abelmoschus esculentus (lady's finger) is cultivated in India for its fruits used as

vegetables.

2. A Cotton fibre of Commerce is obtained from the epidermal hairs of seeds of

Gossypium species. G. herbaceum and G. arboreum are commonly called old world

cotton (diploid plants) while Gossypium hirsutum and G. barbadense are new world

cotton (tetraploid plants).

3. The family yields most important and valuable fibres for textile industries.

4. Hibiscus cannabinus (patsan) is grown as a fibre crop in India to procure bast fibre used

for ropes, cordages, ropes sacking etc.

5. Inferior quality of fibre is also obtained from Abutilon indicum,A. polyamdrum, Urena

lobata, Sida acuta, S. cordifolia, Kydia calycina, Malachra capitata etc.

Oil obtained from the seeds of Gossypiumis used in the manufacture of soaps and

lubricants.

6. The oil cake is an excellent protein rich cattle feed.

127. Seeds of Hibiscus cannabinus yields fatty oil used as lubricant and in the manufacture of linoleum paints and varnishes.

8. Seeds and bark of Urena lobata (bachital) are used to cure hydrophobia. 9. Roots of Malwa verticillataare used against whooping cough and ash of dried leaves in scabies. Roots of Pavonia odorataare used in Indian perfume industry particularly in Heena perfume.

10. Roots of Malachra capitataare used in rheumatism and lumbago. 11. Large number of plants are grown for their ornamental values example Hibiscus rosasinensis (Shoe Flower) for showy large red flowers; H. sabdariffa for yellow showy flowers ; H. mutabilis (cotton rose) double flowers white ,pink or red; Malvaviscus arboreus for pendulous Scarlet flowers; Althea rosea (hollyhock) for sessile brightly coloured red, pink or white flowers; Malva sylvestris for purple-rose flowers etc.

12. Trees grown in Gardens belong to Malvaceae such as Thespesia populnea (Indian Tulip tree).