Crotalaria verrucosa commonly known as blue rattlepod is a species of flowering plant in the legume family, Fabaceae. This shrub belongs to the sub family Faboideae. The plant is native to Bangladesh, China, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, and Vietnam; Australasia and Africa & Americas regions. Sweet Pea, Warty Crotalaria, Tooth-Leaved Rattlepod, Blue-Flowered Rattlepod, Blue Rattlepod, Blue Rattlesnake, Warty Rattlebox, Blue Rattleweed, blue-flowered crotalaria, purple popbush, shack-shack, tooth-leaf rattlepod, Blue Andana, Purple Rattlebox, Warted Crotalaria, Blue Rattle-box and Cascavelle á Fleurs Bleues are few of the popular common names of the plant.
Plant Description
Blue rattlepod is an erect or spreading, much-branched, annual, sub-woody plant that grows about 50 to 100 cm in height. The plant is found growing in fallow fields, marshy ground, along rivers, roads, Grassland, sparse forests, edges, open places in dry evergreen and deciduous forests. Stem is 4-angled, sulcate, shortly appressed or spreading pubescent. Twigs are 3 or 4 winged. Stipules are foliaceous, falcate, about 12-38 mm long and 13-31 mm wide, apex acuminate. Leaf blades are about 6.5-15 cm long and 3.5-5.5 cm wide, petioles are about 0.4-1 cm long, upper and lower surfaces are clothed in short white hairs. Lateral veins are about 7-13 on each side of the midrib.
Flowers
Flowers are subtended by narrow lanceolate, about 9 mm long, bracts, apex inflated and hooked. Flowers about 16-18 x 23 mm. Calyx tube is about 3-4 mm long, lobes about 6 mm long. Stamens ten, filaments fused into a tube about 6-7 mm long, open on one side. Petals: standard about 16 x 12 mm, wings about 12-15 mm long, keel about 12-15 mm long. Stamens dimorphic, the longer filaments with small anthers about 0.8 x 0.8 mm and the shorter filaments with longer anthers about 4 x 1 mm. Ovary densely clothed in white hairs. Style about 8-9 mm, hairy towards the apex. Flowering normally takes place from November.
Fruit
Fertile flowers are followed by cylindrical pods, about 50-80 mm long and 10-16 mm wide, hairy, grooved on one side. Seeds are about 28-32 per fruit. Outer surface of the seeds and the inner surface of the pod are oily. Radicle is adjacent to the cotyledons.
