Araceae
Aridarum rostratum Bogner & A.Hay
SUMMARY
Herb 20-35 cm tall. Stem condensed, 4-5 cm long, 0.5-0.7 cm diam., with tough roots emerging through the leaf bases. Leaves 8-10 together; petiole 5-20 cm long, 1.2-2 mm diam., adaxially canaliculate, sheathing at the extreme base with the wings extended into a sublinear ligular apically rounded portion 4.5-8 cm long; blade narrowly elliptic to narrowly obovate, coriaceous, adaxially dark green, paler abaxially, 6-18 cm long × 2-5.5 cm wide, the base cuneate, the apex cuspidate and apiculate for 1-3 mm, the margin slightly undulate (collector’s note); midrib abaxially prominent, adaxially more or less flush with the lamina, with 5-7 weak primary lateral veins on each side, alternating with faint interprimaries and diverging at 35-40°, running to a marginal vein; secondary venation abaxially and adaxially very faint; tertiary venation obscure. Inflorescence solitary; peduncle slender, exceeding the petioles, 15-22 cm long, 1.2-2 mm diam. Spathe 6-8 cm long, more than twice the length of the spadix, broadly lanceolate, the upper part extended into a long straight beak c. 0.9 cm long, dark green at the base, the remainder white and probably caducous. Spadix subcylindric-spindle-shaped, 2.5-3 cm long; female zone c. 0.8 cm long, thinner than the remainder, narrowly obconic, c. 3 mm diam., adnate to the spathe in the lower ½; pistils crowded; ovary subglobose, c. 1 mm diam.; stigma sessile, discoid, contiguous with neighbouring stigmas, drying dark brown, rather coarsely papillate; placentation basal; interpistillar staminodes absent; sterile interstice slightly obconic, 2 mm long, distally 5 mm diam., 2-4 irregular whorls of sterile stamens from c. 0.5 mm (basal ones) to 0.9 mm diam. (distal ones), these triangular-cordate from above, aligned with the points facing the spadix apex, truncate, verruculate on the surface; male zone c. 1 cm long, 0.5 cm diam., yellow; stamens large, spirally arranged, truncate, circular-rhomboid from above, apically verruculose, 1.2-1.4 mm diam.; thecae together on the proximal (with respect to the spadix axis) side of the anther, with conspicuous 0.8-1.2 mm long upturned horns each ending in a very narrow pore; appendix c. 1 cm long, c. 0.5 cm diam., slightly tapering, obtuse; staminodes of appendix resembling stamens without thecae. Fruit unknown.