5. Orontium. Spadix narrow, naked, terminating the terete scape.
6. Acorus. Spadix cylindrical, borne on the side of a leaf-like scape.
1. ARISÆ̀MA, Martius. Indian Turnip. Dragon Arum.
Spathe convolute below and mostly arched above. Flowers monœcious or by abortion diœcious, covering only the base of the spadix, which is elongated and naked above. Floral envelopes none. Sterile flowers above the fertile, each of a cluster of almost sessile 2–4-celled anthers, opening by pores or chinks at the top. Fertile flowers consisting each of a 1-celled ovary, tipped with a depressed stigma, and containing 5 or 6 orthotropous ovules erect from the base of the cell; in fruit a 1–few-seeded scarlet berry. Embryo in the axis of albumen.—Low perennial herbs, with a tuberous rootstock or corm, sending up a simple scape sheathed with the petioles of the simple or compound veiny leaves. (Name from ἀρίς, a kind of arum, and αἷμα, blood, from the spotted leaves of some species.)
1. A. triphýllum, Torr. (Indian Turnip.) Leaves mostly 2, divided into 3 elliptical-ovate pointed leaflets; spadix mostly diœcious, club-shaped, obtuse, much shorter than the spathe, which is flattened and incurved-hooded at the ovate-lanceolate, pointed summit.—Rich woods, N. Scotia to Fla., west to Minn. and E. Kan. May.—Corm turnip-shaped, wrinkled, farinaceous, with an intensely acrid juice; spathe with the petioles and sheaths green, or often variegated with dark purple and whitish stripes or spots.
2. A. Dracóntium, Schott. (Green Dragon. Dragon-root.) Leaf usually solitary, pedately divided into 7–11 oblong-lanceolate pointed leaflets; spadix often androgynous, tapering to a long and slender point beyond the oblong and convolute pointed greenish spathe.—Low grounds, N. Eng. to Fla., west to Minn., E. Kan., and Tex. June.—Corms clustered; petiole 1–2° long, much longer than the peduncle.
2. PELTÁNDRA, Raf. Arrow Arum.
Spathe elongated, convolute throughout or with a dilated blade above. Flowers monœcious, thickly covering the long and tapering spadix throughout (or only its apex naked). Floral envelopes none. Anthers sessile, naked, covering all the upper part of the spadix, each of 5 or 6 cells imbedded in the margin of a thick and shield-shaped connective, opening by a terminal pore. Ovaries at the base of the spadix, each surrounded by 4–5 staminodia connate into a cup, 1-celled, bearing 1–few amphitropous or nearly orthotropous ovules at the base; stigma almost sessile. Fruit a leathery or fleshy berry, 1–3-seeded. Seed obovate, surrounded by a tenacious jelly, the base empty, the upper part filled with a large and fleshy spherical embryo; no albumen.—Stemless herbs, with arrow-shaped leaves and simple scapes from a thick-fibrous or subtuberous root. Fruit in a globose cluster, enclosed by the persistent fleshy base of the spathe. (Name from πέλτη, a target, and ἀνήρ, for stamen, from the shape of the latter.)
1. P. undulàta, Raf. Root of thick tufted fibres; scape 1–1½° high, about equalling the leaves; basal lobes of the leaves rather long and often acutish; spathe convolute throughout, wavy on the margin, mostly green, 4–7´ long; sterile portion of the spadix several times longer than the pistillate; ovules several; fruit green; seeds 1–3. (P. Virginica, Kunth, and most authors.)—Shallow water, New Eng. to Fla., west to Mich. and Ind. June.
2. P. álba, Raf. Rootstock tuberous, covered with thick-fleshy roots and propagating by offshoots; lobes of the leaves mostly short and broad, obtuse; spathe 3–4´ long, the blade broader, acuminate, somewhat expanded, white; sterile part of the spadix scarcely longer than the pistillate; ovules and seeds solitary; berry scarlet, 5–6´´ long. (P. Virginica, Schott. Xanthosoma sagittifolia, Chapm., not Schott. Caladium glaucum, Ell. Arum Virginicum, L., in part?)—Marshes, S. Va.(?) and N. C. to Fla.