304 SYSTEMATIC BOTANY. 



1. Arum. Flowers mostly monoecious, situated at the base of a 

 spadix, which is naked above. Fertile flowers below. Barren above, 

 inclosed in a cucullate spathe. Perianth none. Berries distinct, i- 

 celled, several-seeded. K 



A. TRIPHYLLUM (Indian Turnip}. Acaulescent ; leaves mostly 2, on 

 long petioles, sheathing at base, ternate ; leaflets ovate or oval, acuminate, 

 sessile ; spadix shorter than, and included within the ovate, acuminate 

 spathe, which is flattened and bent over the top of the spadix, and is fre- 

 quently marked with dark purple or whitish spots or stripes, otherwise of a 

 dark, shining green. Common in rich, rocky woods. May. 



2. Peltandra. Flowers monoecious, covering the long spadix. 

 Spathe elongated, convolute. Perianth none. Anthers on the upper 

 part of the spadix, sessile, peltate. Ovaries at the base of the spadix. 

 Berries distinct, i-celled, i-3-seeded. -4 



P. VIRGINICA (Arrow Arum). Acaulescent ; leaves oblong-sagittate, 

 acute at apex, with obtuse lobes, on long petioles, dark, shining green, of 

 large size ; spathe elongated, curved at apex, dark green, enveloping the 

 slender spadix ; ovaries sessile, becoming a bunch of green berries. A 

 water-plant, io'-i8' high. June-July. 



3. Calla. Spathe ovate, spreading, persistent. Spadix covered 

 with flowers, the lower perfect, the upper often entirely staminate. 

 Perianth none. Berries distinct, several-seeded. 



C. PALUSTRIS (Water Arum}. Acaulescent; leaves cordate, on long, 

 sheathing petioles, shining green, large and smooth. Herb in cold bogs with 

 creeping root-stock. 



4. Acorus. Spathe none ; spadix lateral, sessile, densely flowered. 

 Flowers perfect. Sepals 6. Stamens 6. Anthers reniform. Stig- 

 mas sessile, minute. Ovaries 2-3-celled, becoming dry and few- 

 seeded, y. 



A. CALAMUS (Sweet Flag). Rhizoma creeping ; leaves long, light 

 green ; scape long, resembling the leaves, bearing the sessile spadix on its 

 edge, just above the middle ; spadix covered with yellowish-green flowers. 

 Common in wet grounds. June- July. 



5. Symplocarpus. Spathe with an incurved point, fleshy. Spa- 

 dix pedunculate, oval, entirely covered with the perfect flowers. Se- 

 pals 4, persistent. Stamens 4. Style 4-angled. Stigma minute. 

 Seeds large, globular, imbedded in the enlarged, spongy spadix. 



S. FCETIDUS (Skunk Cabbage). Acaulescent ; leaves ovate, cordate at 

 base, acute, on short petioles, at length very large ; spadix preceding tha 

 leaves, enveloped in a spathe, striped with purplish brown ; flowers crowded 

 on the spadix, dull-purple. Common in swamps and wet meadows, with 

 offensive odors, resembling that of a skunk. March-April. 



