140 ONAGRACEJE. (EVENING PRIMROSE FAMILY.) 
* Stamens 8: petals deciduous: carpels even : leaves whorled in threes. 
X. Iff. spicatum, L. Leaves all pinnately parted and capil¬ 
lary, except the floral ones or bracts , which are ovate and entire or 
toothed , chiefly shorter than the flowers , which thus appear to form an 
interrupted leafless spike.—Deep water, common. July, Aug.— 
Stems long, slender. 
2. IH. verticillatum, L. Lower leaves as in No. 1; the 
floral ones much longer than the flowers , pectinate-pinnatifid. Ponds, 
New York and westward. Stouter than the last. 
* * Stamens 4 : petals rather persistent : carpels 1-2 -ridged and rough¬ 
ened on the back: leaves whorled in fours and fives , the lower w 
very slender capillary divisions. 
3. HI. lieteropliyllum, Michx. Stem rather stout; flora 
leaves ovate and lanceolate , thick, crowded, sharply serrate, the low 
est pinnatifid ; fruit obscurely roughened. — N. New York and west 
ward along the Great Lakes. — Stouter than the foregoing. 
4. HI. scabratum, Michx. Stem rather slender; lower leaves 
pinnately parted with few capillary divisions ; floral leaves linear 
(rarely scattered) pectinate-toothed or cut-serrate ; carpels strong y ' 
ridged and roughened on the back. — Shallow ponds, Ohio and sout l 
ward. Block Island, Rhode Island, Robbins. 
* * * Stamens 4 : petals rather persistent: carpels even on the back. 
leaves chiefly scattered or wanting. 
5. HI. aillbiglllllll, Nutt. Immersed leaves pinnately parte 
into about 10 very delicate capillary divisions; the emerging ones pec 
tinate , or the upper floral linear and sparingly toothed or entire , flow 
ers mostly perfect; fruit (minute) smooth. — Var. 1. nAtans . stems 
floating, prolonged. Var. 2. capillaceum : stems floating, long an 
very slender; leaves all immersed and capillary. Var. 3. limoscm . 
small, rooting in the mud; leaves all linear, incised, toothed, or en 
tire. — Ponds and ditches, Massachusetts to New Jersey and I enn., 
near the coast. 
6. M. tenellum, Bigelow. Stems nearly leafless and scape 
like, tufted and rooting at the base, upright, simple; bracts small, en 
tire ; flowers alternate, monoecious ; fruit smooth. — Border of pon s > 
Maine to New York, chiefly near the coast. July. — A pecu iar 
plant, 4' - KF high, with shorter sterile shoots. 
8. HIPPLBIS, L. MareVtail. 
Calyx entire. Petals none. Stamen 1, inserted on the edge 
of the calyx. Style single, thread-shaped, stigmatic down one 
side, received in the groove between the lobes of the anther. 
Fruit nut-like, 1-celled, I-seeded. — Perennial aquatics, with sim 
