228 ARACEAE 
4. PISTIA L. 
Free-floating herbs, with fibrous roots. Stems jointed. Leaves clustered at the nodes : 
blades broadened upward, simple, entire. Spathes axillary, sessile or nearly so, tubular 
below, spreading above. Spadix adnate to the spathe. Flowers few, monoecious : pistil- 
late solitary on lower part of spadix : staminate above, subtended by a cup-like involucre. 
Perianth wanting. Anthers 3-8-celled : sacs opening transversely. Ovary 1-celled. 
Ovules several, ascending, orthotropous. 
1. Pistia Stratidtes L. Foliage nearly glabrous. Roots furnished with numerous 
hair-like rootlets : stems elongating : leaves clustered ; blades cuneate or obovate-cuneate, 
4-13 cm. long, rounded or notched at the apex, prominently nerved beneath : spathes 
white, or partially so, about 1.5 em. long, short-peduncled, villous, the lower part convo- 
lute, the upper part flat, ovate : spadix adnate to the spathe : pistil solitary. 
In still water, Florida to Texas. Also throughout the tropics. WATER LETTUCE. 
5. SPATHYEMA Raf. 
Swamp-inhabiting stinking herbs. Leaves basal: blades ample, cordate, leathery. 
Scapes erect, partly underground, very thick. Spathe shell-like, leathery, often varie- 
gated, slightly twisted at the apex. Spadix oblong or globose, completely enclosed in the 
spathe, short-stalked. Flowers perfect, covering the spadix. Perianth of 4 hooded mem- 
bers. Stamens 4: anthers 2-celled ; sacs opening lengthwise, extrorse. Ovary sunken in the 
spadix, l-celled: style pyramidal, 4-sided: stigma minute. Ovule solitary, anatropous, 
suspended. Fruits immersed in the spadix, adnate to the accrescent fleshy perianth. 
Seed solitary, irregular. Endosperm wanting. [Symplocarpus Salisb. ] 
1. Spathyema foétida (L.) Raf. Foliage glabrous. Herbage garlic-scented : leaf- 
blades ample, 2-9 dm. long, oblong to ovate, obtuse, undulate, thick, truncate or subcor- 
date at the base: petioles stout, shorter than the blades: scapes erect, mostly subterranean : 
spathe preceding the leaves, 8-15 cm. long, ovoid, with a more or less curved beak, green- 
ish or yellowish, mottled with purple: spadix subglobose, 2-2.5 em. becoming 10-15 cm. 
in diameter at maturity : fruits spheroidal or globose, green: seeds subglobose, 9-15 mm. 
thick. [Symplocarpus foetidus (L.) Nutt.] 
In swamps or low grounds, Nova Scotia to Minnesota, Florida and Missouri. Winter or early 
spring. SKUNK CABBAGE. MIDAS’ EARS. 
6. ORONTIUM L. 
Aquatic or swamp-inhabiting herbs, with deeply buried rootstocks. Leaves basal : 
blades flat. Scapes terete below, enlarged under the spadix. Spathe enclosing the spadix 
when young, persisting as a sheath-like bract at its base or deciduous. Spadix golden 
yellow, terminal, naked. Flowers perfect, covering the spadix.  Perianth of 4-6 (6 be- 
low, 4 above), scale-like imbricated sepals. Filaments broader than the anthers, abruptly 
contracted above. Anther-sacs 2, spreading, opening by oblique valves. Ovary 1-celled, 
depressed, sunken in the spadix-axis. Ovule solitary, half-anatropous.  Utricle green. 
Seed solitary. Endosperm wanting. 
1. Orontium aquàticum L. Rootstock thick, uneven : leaf-blades thickish, oblong 
or elliptie, 1-3 dm. long, acute or apiculate, entire, gradually or abruptly narrowed 
at the base, sometimes lustrous, often inequilateral, petioled : scapes solitary or clustered, 
terete, or flattened below the spadix, 2-6 dm. long, or elongating and reclining at maturity : 
spathe bract-like, 4-10 cm. long, 2-keeled on the back, early falling away : spadix yellow, 
tapering upward, 2-6 cm. long: utricles spheroidal. about 1 em. thick, few developing. 
In swamps and shallow ponds, central Massachusetts to Florida and Louisiana. Spring. GOLDEN- 
CLUB. Boc TORCHES. 
7. ACORUS L. 
Swamp-inhabiting herbs, with elongated aromatic pungent rootstocks. Leaves basal: 
blades linear, sheathing each other and the base of the scape. Scapes erect, 3-angled, 
keeled on the back, channeled on the front, rather leaf-like. Spathe sword-like, ap- 
parently a prolongation of the scape. Spadix conic-cylindric, laterally attached, naked. 
Flowers perfect, crowded on the surface of the spadix-axis. Perianth of 6 concave 
membranous members. Filaments flattened. Anthers reniform or sagittate : sacs 2, con- 
