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Araceae
Dieffenbachia beachiana Croat & Grayum
SUMMARY
Slender herb, 40-100 cm tall; stems briefly creeping at base; internodes 2-6 cm long, 1.5-3.5 cm diam., medium green to olive-green, sometimes streaked with cream, semiglossy and obscurely roughened. LEAVES clustered near stem apex, erect-arching; petioles 17-46 cm long (averaging 26.5 cm long), sheathed 25Wo-83Wo of petiole (averaging 54%); sheath 10-22 cm long (averaging 14.2 cm), decurrent at apex; unsheathed portion (2.5)10-30 c m long, broadly C-shaped in cross section, dark green to brownish, flattened with acute, erect margins or sharply to bluntly sulcate adaxially, surface pale green-mottled, matte, usually minutely roughened and with scattered scales, whitish raphide c e11s visible, drying with scattered clusters of pustular raised areas with granular-puberulent protrusions; Blades narrowly elliptic to lanceolate, rarely narrowly ovate, inequilateral, one side 1-2 cm wider than the other side, thinly coriaceous to subcoriaceous, drying papyraceous, weakly bicolorous, ± equilaterally acuminate at apex (the acumen to 5 mm long), slightly inequilateral and acute, rounded or truncate (rarely subcordate in Panama) at base, 16-41 cm long, 6.5-15 cm wide (averaging 28 x 10.7 cm), 1.8-5.3 times longer than wide (averaging 2.6), 0.7-1.9 times longer than petioles (averaging 1.12 times longer than petioles); margins crisped-undulate; upper surface dark green (in Panama sometimes mottled with white or cream), semiglossy (rarely matte), lower surface semiglossy to weakly glossy or matte, slightly paler; midrib flatraised above, often striate, usually concolorous above, convex to thicker than broad below, puberulent with thick, whitish trichomes below; primary lateral veins 23 to 30(36) per side, departing midrib at a 70°-110° (to 45° toward apex and sometimes at base) angle, arising acutely then straight to weakly curved to the margins (then sweeping prominently toward apex), usually quilted-sunken above, convex, puberulent with thick, whitish trichomes, sometimes with adjacent veins alternating ascending and descending below; interprimary veins usually present, scarcely less visible than primary lateral veins; minor veins moderately distinct and weakly raised below. INFLORESCENCES 1 to 3 per axil; peduncle 9-13 cm x 5-7 mm, drying 3- 4 mm diam.; spathe 10-19 cm long, gradually constricted at middle, green throughout, gradually long-tapered to apex; spathe blade to 3 cm diam. when flattened; spathe tube 1-2 cm diam.; spadix 13-15 cm long; pistillate portion 4.5-6 cm long, drying 7 mm diam. throughout; fertile staminate portion 5-6.5 cm long, drying 4 mm diam. through- out; intermediate mostly sterile portion usually 2- 3.5 cm long, 2 mm diam., sometimes with pistillate and staminate portions almost contiguous; pistils 46 to 66(100), 2 to 4 situated across the width of the spadix, ovary oblong-ellipsoid, 1.5-2 x 1-1.6 mm; stigmas subgloloular, about as broad as the ovary; staminodia narrowly clavate, usually not at all fused at base, ca. twice as long as pistil; synandria 1.8- 2.6 mm diam., margins irregularly subrounded drying smooth and light brown at apex. INFRUC'I'ESCENCE, with spathe (10)14-16 cm long, somewhat flattened, yellow-green mottled green and white with darker flecking, maturing to orange; spadix 6-10 m long; berries orange, subglobose, 6-8 mm diam.