sterculiaceaed

 13. STERCULIACEAE

Distribution: The family is represented by 50 genera and 750 species distributed mainly in tropical parts of the world. In India, some 18 genera and over 90 species are found in tropical parts and Himalayas. Common Indian examples are Heritiera littoralis (Sundari, the Sundarban is named after this tree), Ptetospermum acerifolium, Guazuma ulmifolia, Helicteres isora, Dombeya mastersii etc. Salient feature: Pollination and dispersal Flowers show entomophily and seeds show anemochory (winged seeds) or Zoochory. Description:Vegetative characters such as, plants are usually softwood trees or shrubs rarely herbs (Pentapetes) or climbers (Buettneria species). Young parts are often stellate - tomentose. Flowers unisexual or bisexual; calyx colored in Sterculia; staminodes present; placentation is axile. Leaves: Leaves are alternate, simple, entire or palmately lobed or Digitate (e.g Sterculia). Stipules are present and caducous. Inflorescence: Flowers are found arranged in axillary complex cymes. Sometimes cauliflowery is met, as in Theobroma. Flowers:Flowers are bracteate, hermaphrodite, actinomorphic and zygomorphic pentamerous and hypogynous. Flowers are unisexual in Sterculia. Calyx: Consist of five sepals, somewhat basally connate with valvate aestivation. Sepals are often colored in Sterculia. Corolla: Comprises five petals, often minute and deciduous, occasionally absent as in Sterculia. Petals are free or adnate to the base of staminal tube. In Dombeya, petals are persistent. Androecium: Consists of few to many stamens, free or often connate into a tube and antisepalous. In Melochia, 5 stamens is it the petals and connate below, are found and inPentapetes and Pterospermum, there are 20 stamens 15 fertile in five groups of three each alternating with 5 antipetalous staminodes. In Sterculia, numerous stamens with sessile anthers on a staminal column are found while in Melhania, 10 stamens connate below to form a short tube, are found. Staminodes are often present alternating with the fertile stamens and are antipetalous. In Guazuma, stamens and staminodes connate together in a monoadelphous cup. Anthers are dithecous, parallel or divergent. Gynoecium:qConsists of 2-5 carpels. Ovary is syncarpous and superior. Number of locules corresponds to the number of carpels rarely 10 to 12 locules are found. Ovary is sessile,

14sometimes androgynophore may be found. Placentation is axile with few to many anatropous

ovules. Style is simple or lobed or rarely divided upto the base, the number being equal to the

number of carpels.

Fruit: Fruit is indehiscent or dehiscent capsule,sometimes separating into cocci. Capsule is

woody in Pterospermum.

Seeds:Endospermic or non endospermic. Sometimes, seeds are winged (as in Pterospermum)

or arillate (Sterculia).

Floral formula: Br Brl K 5 C 5 A∞G(2-5)

Guazuma tomentosa

Economic Importance

1. Several species are grown as in ornamentals e.g. Dombeya spectabilis, Pentapetes

phoenicea (Dopharia), Guazuma ulmifolia, Pterospermum acerifolium (The

Muchkundo Champa), and many species of Sterculia.

2. Fruit extracts of Helicteres isora (Marorphali) are used in diabetes and seed decoction

H. littoralis is given for the treatment of diarrhoea and dysentry.

3. Roasted seeds of Guazuma ulmifolia are stringent and are used in stomach disorders.

Fruits of Sterculia balanghas are laxative.

4. Several species of Pterospermum, Sterculia, Pterygota and Heritiera yield

useful timber for furniture, cabinet and construction work.

5. Bark of Abroma augusta, Pterygota alata and several species of Sterculia (S.

balanghas, S. gutta) producers good course fibres used for cordages.Seeds of

Theobroma cacao (cocoa tree) after roasting and cocoa powder (a nutritious beverage

and chocolate) used as food world over.

156. It is now commercially cultivated in South India. Seeds of Cola acuminata (kola nut) contain caffeine and Theobromine and are used as soft drinks or beverages. 7. Sterculia urens is the source of Karaya gum used in textile industry.