Achyranthes aspera (common names: chaff-flower, prickly chaff flower, devil's horsewhip, Sanskrit: अपामार्ग apāmārga) is a species of plant in the family Amaranthaceae. It is distributed throughout the tropical world. It can be found in many places growing as an introduced species and a common weed. It is an invasive species in some areas, including many Pacific Islands environments.
Description
Habit: a wild, perennial, erect herb.
Stem: herbaceous but woody below, erect, branched, cylindrical, solid, angular, hairy, longitudinally striated, nodes and internodes are prominent, green but violet or pink at nodes.
Leaves: ramal and cauline, simple, exstipulate, opposite decussate, petiolate, ovate or obovate, entire, acute or acuminate, hairy all over, unicostate reticulate.
Inflorescence: a spike with reflexed flowers arranged on long peduncle.
Flowers: bracteate, bracteolate, bracteoles two, shorter than perianth, dry, membranous and persistent, sessile, complete, hermaphrodite, actinomorphic, pentamerous, hypogynous, small, spinescent, green.
Bracts: ovate, persistent, awned.
Perianth: made up of 5 tepals, polyphyllous, imbricate or quincuncial, green, ovate to oblong, persistent.
Androecium: made up of 10 stamens, out of which 5 are fertile and 5 are scale-like, fimbriated, sterile staminodes, both alternating with each other, fertile stamens are antiphyllous, monadelphous, filaments slightly fused at the base, dithecous, dorsifixed or versatile, introrse.
Gynoecium: it is bicarpellary, syncarpous, superior, unilocular, ovule one, basal placentation, style single and filiform, stigma capitate.
Fruits: oblong utricle
Seeds: endospermic with curved embryo, 2 mm long, oblong black.
Flowering and Fruiting time: September to April
Uses
The juice of this plant is a potent ingredient for a mixture of wall plaster, according to the Samarāṅgaṇa Sūtradhāra, which is a Sanskrit treatise dealing with Śilpaśāstra (Hindu precepts of art and construction).
