Ambrosina bassii L.

HABIT: very small herbs, seasonally dormant, stem a rhizomatous tuber. LEAVES : 2-4. PETIOLE : sheath short, subequal to blade. BLADE : ovate or ovate-elliptic, obtuse, often spotted; primary lateral veins 2-3 on each side, mostly arising at petiole insertion, arcuate, running into apex, higher order venation reticulate. INFLORESCENCE : Solitary, lying horizontally on ground. PEDUNCLE : short, hypogeal, elongating in fruit. SPATHE : ellipsoid, boat-shaped, not constricted, basally convolute, gaping above, interior surfaces bearing hair-like processes, stellate hairs occurring on inner and outer surfaces of ventral (pistillate) chamber, apex forming curved beak. SPADIX : enclosed by the spathe, shortly appendiculate, adnate to internal wall of spathe by septum-like lateral dilations thus forming two longitudinal chambers separating male flowers from female; ventral chamber (held uppermost) containing single female flower, dorsal chamber (held lowermost) containing usually 16 thecae arranged in two parallel rows of 8 each. FLOWERS : unisexual, perigone absent. MALE FLOWER : each row of 8 thecae represents 4 sessile stamens (see note), thecae oriented transversely, opening by longitudinal slit. POLLEN : extruded in irregular masses, inaperturate, ellipsoid-oblong, medium-sized (44 µm.), exine striate-reticulate, with narrow undulate striae in “football” pattern, breaking up into verrucae at ends. FEMALE FLOWER : ovary 1-locular, ovules many, orthotropous, funicles rather long, placenta discoid, basal, style long, attenuate, curved towards spadix axis, stigma discoid, flattened, held parallel to spadix axis. INFRUCTESCENCE: BERRY: depressed-globose, many-seeded, style and old stigma persistent, whitish with reddish tinge. SEED : subglobose to ellipsoid, testa costate with weak reticulation, brown, hard, with large, white, conical strophiole (aril), embryo straight, elongate, endosperm copious.