onagkacejE. (evening primrose family.) 143 



6. CIRC-ffiA, 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. IiUtetiana, 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. PBOSEBPINACA, L. 



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

 bony, 3-angled, 3-cellcd, 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 ° - 1 J° long, ascending or floating. 



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

 fruit rugose. — With the preceding. — Stem 3' - 1 2' long. 



8. MYEIOPHYLLUM, Vail. Water-Milfoil. 



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

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

 recurved. Fruit bony, 4-celIed, 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 waHtj. 



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

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

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

 nute w^arts, with the lobes obtuse. — Ponds and lakes. Middle and West Florida. 

 — July. 



2. M. vertieillatum, 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 



