Q.(a) Write the floral characters of Ricinus communis. Draw any one of the floral diagram and write its floral formula. OR

Family Euphorbiaceae supplies economically valuable rubber, oil, food, medicine, and ornamental plants, illustrated by well-known genera such as Hevea, Ricinus, Manihot, Phyllanthus, and Euphorbia/Croton.

Family Euphorbiaceae (the spurge family) is a large dicot family with diverse economically important members:

1. Rubber — Hevea brasiliensis (the Para rubber tree) is the primary commercial source of natural rubber, obtained by tapping the latex from its bark; this rubber is used to manufacture tyres and countless other rubber products.

2. Oil — Ricinus communis (castor) seeds yield castor oil, an important non-edible oil used in medicine (as a laxative), as a lubricant, and in the manufacture of soaps, paints, and cosmetics.

3. Food — Manihot esculenta (tapioca/cassava) produces starchy tuberous roots that are an important staple food/carbohydrate source in many tropical regions, and are processed into tapioca pearls/starch.

4. Medicine — Phyllanthus emblica (amla/Indian gooseberry) produces a fruit rich in Vitamin C, widely used in traditional (Ayurvedic) medicine and in food preparations/preserves.

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Ricinus communis (castor), of family Euphorbiaceae, is a monoecious plant bearing separate, petal-less male and female flowers on the same raceme, with the male flowers having numerous branched stamens and the female flowers a tricarpellary, trilocular superior ovary.

Floral characters of Ricinus communis (Castor, family Euphorbiaceae):

• Habit and inflorescence: Ricinus is monoecious (male and female flowers borne separately but on the same plant), with both flower types unisexual, arranged together on a raceme (often appearing as a panicle), with male flowers positioned toward the base and female flowers toward the top of the inflorescence axis.
• Symmetry: flowers are actinomorphic (radially symmetric).
• Perianth: the calyx has 3 to 5 sepals, valvate in aestivation; a corolla (petals) is absent in both male and female flowers.
• Male flower: androecium consists of numerous stamens (polyandrous) with branched filaments, bearing many anthers — an adaptation that produces abundant pollen for wind pollination; the gynoecium is absent (since the flower is unisexual/male).
• Female flower: androecium is absent; the gynoecium is tricarpellary, syncarpous (carpels fused), with a superior ovary that is trilocular (three chambers), each locule containing a single ovule attached by axile placentation. The ovary surface is often covered with soft spines. The style is short, and it divides into three, each further bifid (so appearing 6-branched), bright-red, feathery stigmas that catch airborne pollen.
• Fruit: a spiny, three-lobed capsule (regma) that splits explosively at maturity to disperse the three seeds, each rich in castor oil. …