ONAGRACE.E. (EVENING PRIMROSE FAMILY.) 143 



6. CIRC.2EA, Tourn. 



Calyx-tube slightly produced beyond the ovary, the limb 2-cleft, deciduous. 

 Petals 2, obcordate. Stamens 2. Style filiform. Capsule obovate, 1 - 2-celled, 

 1 - 2-seeded, bristly with hooked hairs. Perennial herbs, with opposite petioled 

 leaves, and small white or rose-colored flowers in loose terminal racemes. 



1. C. Lutetiana, L. Minutely pubescent ; leaves ovate, acuminate, slight- 

 ly toothed, usually longer than the petioles; bracts none; capsule hispid. 

 Damp shades along the mountains, Georgia and northward. July. Stem 

 l-2 high, tumid at the joints. Fruit reflexed. Flowers reddish-white. 



2. C. alpina, L. Smooth; stem low (3' -8'); leaves cordate, coarsely 

 toothed, as long as the petioles ; pedicels minutely bracted ; capsule hairy. 

 With the preceding. 



7. PROSERPINACA, L. 



Calyx-tube 3-sided, 3-lobed. Petals none. Stamens 3. Stigmas 3. Fruit 

 bony, 3-angled, 3-celled, 3-seeded. Herbs with pinnately dissected leaves, and 

 minute axillary greenish flowers. 



1. P. palustris, L. Leaves lanceolate, sharply serrate, the submerged 

 ones pectinate. Ponds and ditches, Florida to Mississippi, and northward. 

 June -August. Stem 1- l long, ascending or floating. 



2. P. pectinacea, Lam. Leaves all pectinate, the divisions filiform; 

 fruit rugose. With the preceding. Stem 3'- 12' long. 



8. MYBIOPHYLLUM, Vail. WATER-MILFOIL. 



Flowers monoecious or polygamous. Calyx 4-parted in the sterile flowers, 4- 

 toothed in the fertile ones. Petals 4 or none. Stamens 4 or 8. Stigmas 4, 

 recurved. Fruit bony, 4-celled, 4-lobed, indehiscent. Aquatic perennial herbs, 

 with the submerged leaves pinnately divided into filiform or capillary segments, 

 and commonly whorled. Flowers minute in the axils of the upper leaves ; the 

 uppermost sterile. 



* Stamens 8 : fruit even or warty. 



1. M. laxum, Shuttl. Stem long, slender ; leaves 4 in a whorl ; the floral 

 ones reduced to minute nearly entire spatulate bracts, shorter than the flowers, 

 which thus form an interrupted almost naked spike ; fruit roughened with mi- 

 nute warts, with the lobes obtuse. Ponds and lakes, Middle and West Florida. 

 July. 



2. M. verticillatum, L. Leaves in whorls of 3-4, the floral ones linear, 

 pectinately toothed, much longer than the flowers ; fruit smooth. Still water, 

 Florida, and northward. July. Stem 2 - 4 long, stouter than the last. 



* * Stamens 4 : fruit ridged and roughened. 



3. M. heterophyllum, Michx. Stem thick; leaves 4-6 in a whorl, 

 the floral ones crowded, ovate or lanceolate, finely and sharply serrate ; the lower 



