Arum dioscoridis Sm.

Tuberous herb sprouting in early autumn from a discoid, vertically orientated tuber 5-10 cm across, 2.5-3 cm thick. Petiole terete, 13-50 cm long, 4-7 mm wide, mid-green, sometimes longitudinally striped with whitish green, more rarely stained with purple. Leaf-blade oblong-hastate to narrowly sagittate-hastate, apex acute, 13-45 cm long, 9-27 cm wide, mid-green, the main and secondary lateral veins sometimes conspicuously paler. INFLORESCENCE smelling strongly of donkey dung and carrion, rarely odourless. Peduncle usually much shorter than the leaves, rarely almost equalling the petioles, terete, 3.5-10(-42) cm long, 4-10 mm wide, mid-green, rarely stained with purple. Spathe 11-40 cm long; spathe-tube oblong-cylindric, 3-8 cm long, 2-3.5 cm wide, moderately constricted apically, exterior pale to mid-green, sometimes suffused with purple above and along the margin, interior greenish white, the apical portion sometimes stained with purple; spathe-limb lanceolate to lanceolate-elliptic, erect, acute to acuminate, 8-37 cm long, (2-) 4-11 cm wide, externally pale to mid-green, occasionally stained with purple, especially towards the margin, internally greenish white to mid-green, variously blotched and stained with deep purple-maroon to black-purple, sometimes ± unspotted (var. syriacum) or ± uniformly purple (var. philistaeum). Spadix ½ as long to just exceeding the spathe-limb, 12-28 cm in total length; appendix stout-cylindric, fusiform cylindric or slender-cylindric, almost lacking a stipe to rather long-stipitate, 6-32 cm long, 3-12 mm wide, sooty purple to maroon-purple, very rarely dull yellow, stipe occasionally paler. Staminodes in 2 or 3 whorls forming a zone 1.5-8 mm long; bristles subulate to subulate-filiform, stiff, 2.5-9 mm long, cream to dull purple; bases bulbiform, verrucate, cream, sometimes stained with purple. Interstices: upper 0-5 mm long, longitudinally ridged, cream to dull yellow; lower 0-3 mm long, divided into ± diamond-shaped areas, cream to dull yellow. Staminate flowers in an oblong zone 2.5-8.5 mm long, 4.5-6 mm wide, anthers cream to cream with purple tips , connectives cream or purple. Pistillodes in (1-)2-5 whorls forming a zone 2.5-10 mm long; bristles subulate to subulate-filiform, stiff, 2-7 mm long, cream, to dull purple; bases compressed-bulbiform, verrucate, cream, sometimes stained with purple. Pistillate flowers in an oblong-cylindric cluster 8-30 mm long; ovaries oblong, somewhat truncate apically, pale green to pale yellow, stained with dark purple around the stigma; stigma pale lilac to dirty white. Fruiting spike stout-cylindric, 4-9 cm long, 2-3 cm wide; berries oblong-pyriform, 5-11 mm long, 4-6 mm wide. Germination epigeal.