English: Verticillaster.
Names: Thumbai; Thumba.
Region: India; Philippines, Mauritius, Java.
Habitat: dry, open, sandy soil; areas with waste.
Source: Ayurveda, Bhavaprakasha, Chopra.
Culture: used in witchcraft.
Use: medicine; agriculture; herb for fragrance to food; insecticide.
BotanyAnnual herb, undershrub; 15 to 60 cm tall.
Roots: contain epidermal cells, very narrow, closely packed together; cell walls are very thin, flattened, straight; parenchyma in the cortex contains thick walls, cells are polygonally shaped and contain a large amount of starch grains; cambium separates the phloem and xylem, which are globose to subglobose.
Stem: quadrangular; much branched; hispid or scabrid; with a wide stele; epidermis covered with a thick waxy cuticle; contains few traversed stomata; xylem tissue is radially organized and the parenchymatous phloem tissue is very narrow; phloem tissue widens with age.
Leaves: opposite, subsessile or short petioled; linear or narrowly oblong, lanceolate; entire or distantly crenate, obtuse, narrowed at the base; up to 8 cm long, 1.25 cm broad; petioles 2 to 6 mm long; epidermis is covered with a thick waxy cuticle and is traversed with stomata.
Inflorescence: auxiliary whorls or dense terminals.
Flowers: white; small; bisexual, irregular, zygomorphic, hypogynous; without a peduncle or stalk; with 6 mm long bracts equaling the calyx, bristle-tipped, linear, acute, ciliate, with long slender hairs.
Calyx: sepals 5, gomosepalous, 10 nerved, tubular, curved, 6 to 10 toothed, contracted at the mouth, glabrous below, ribbed and scabrid above, mouth oblique, produced on the upper side; teeth short, triangular;
Corolla: petals 5, gamopetalous, bilabiate, densely white-woolly tube annulate, lower lip 3 fid, spreading, mid lobe large; upper lip 2 fid, erect, concave, villous outside, white; 1 cm long, 5 mm long length.
Androecium: stamens 4, epipetalous, didynamous, ascending, the upper pair shorter; anthers connivent, cells divericate, ultimately confluent.
Gynoecium: carpels 2, syncarpous, ovary superior, 2 celled but at maturity four celled due to the formation of septum, axile placentation, 1 ovule in each chamber; style gynobasic, long; stigma bifid subulate, upper lobe minute or obsolete.
Fruit: brown, smooth, oblong nutlets; ± 3 mm long; outer portion is rounded while the inner portion is angular.