ALISMACEiE. 377 



sule 2 — 3-celled. Seeds often twin ; albumen fleshy. — Herba- 

 ceous plants, with flat narrow mostly sheathing leaves. 



1. COMMELYNA. Lmn.—Dsiy Flower. 



(In honor of two Dutch botanists, John and Gaspar Commelyn.) 



Perianth in 2 rows ; outer one 3.-leaved,' calycine ; inner 3- 



leaved, petaloid. Stamens 6, 3 — 4 sterile and furnished with 



cruciform glands. Capsule 3-celled, 3-valved ; one of the valves 



often abortive. 



1. C. nngustifolia Mich.: assurgent, slender, weak, somewhat smooth; 

 leaves linear-lanceolate, very acute, flat, smooth ; sheaths subciliate ; inner 

 segments of the perianth unequal, one very minute ; bracts peduncled, 

 broad-cordate. C. ereda Willd. 



Borders of swamps. N. Y. to Car. June. %. — Stem a foot high, somewhat 

 branching from the base. Flowers blue. Fertile stamens 2. 



Narrow-leaved Day-flower. 



2. C. Virginica Linn. : stem stiffly erect, pubescent ; leaves long-lance- 

 olate, somewhat petiolate, the sheaths bearded at the throaty inner seg- 

 ments of the perianth nearly equal ; bracts subsessile. C. longifolia Mich. 



Woods. Penn. Muhl. S. to Car. July. %..-^St€m 2 feet high. Flowers 

 blue, clustered at the top of the stem. Fertile stamens 3. 



Broad-leaved Day-flower. 



2. TRADESCANTIA. Z,z?m.— Spiderwort. 

 (In honor of John Tradescant, gardener to Charles I. Torr.) 



Perianth in 2 rows ; the outer one 3 -leaved, calycine ; inner 

 one 3-leaved, petaloid. Stamens 6, all fertile. Filaments villous. 

 Stigma obtuse. Capsule 2 — 3-celled, 3-valved, few-seeded. 



1. T. Virginica Linn. : stem erect, sometimes branching, smooth ; leaves 

 long, lanceolate, smooth ; flowers in an imperfect umbel, sessile ; calyx 

 pubescent. T. cristata Walt. 



Shady woods. N. Y. to Geor. W. to Miss. May. %— Stems about a foot 

 high, often several from tlie same root. Flowers purple, in a terminal cluster or 

 umbel, with a large 2-leaved involucre at base. Virginian Spiderwort. 



2. T. rosea Mich. : erect, simple ; leaves linear, long, smooth ; peduncles 

 elongated ; calyx smooth. T. Virginica Walt. 



Moist woods. Penn. to Geor. May. %. — Stem 8 — 12 inches high. Flowers 

 smaller than in the preceding, with the inner segments rose-colored, and three 

 times as long as the outer ones. Rose-colored Spiderwort. 



Order CXL. ALISMACE^.— Alismads. 



Perianth 6 -leaved, in two rows ; outer row herbaceous, inner 

 petaloid. Stamens definite or indefinite. Ovaries several, 1- 

 celled ; styles and stigmas as many as the ovaries. Fruit not 



