Endogene. 95 
Potamogeton. Pond weed. 
* Upper leaves floating. 
1522, Potamogeton natans, Linn. Pond-weed. July—Aug. 
1to4f. 2%. Ponds and lakes, O. Ky. 
1523. P. fluitans, Linn. River-weed. July—-Aug. 1 to4. Y. 
Running streams. Ohio. 
1524. P. | aa ea Various-leaved pond-weed. Aug. 
2to3f. Y%. pl. A pond 6 miles east from Cin. O. 
** Teaves all submersed. 
1525. P. perfoliatum, Linn. Perfoliate pond-weed. July. %. 
pl. Louisville. M’Murt. 
1526. P. lucens, Linn. Shining pond-weed. Aug. Long and 
large. &. pl. Streams, &c. Ky. St. 
1527. P. compressum, Linn. Flat-stem pond-weed. July—Aug. 
Small, branched; leaves 2i. 2%. In water. Ky. St 
Old Riner, Hamilton, O. 
1528. P. pectinatum, Linn. Fennel-leaved pond-weed. June. 
1to2f. x. pl. Rivers. Ohio. 
1529. P. pauciflorum, Pursh. P. gramineum, Michz. Grass- 
leaved pond-weed. July-Aug. 8tol8i. Y%. pl. &c. 
O. Ky. 
1930. P. acutifolium, Link. Sharp-leaved pond-weed. July. 
y. pl. Ky. St. Leaves linear, acuminate, 3-nerved; 
spike oval, compact, equal in length to the peduncle. 
Hook. Brit. Fl. 74. 
CCLIX. JUNCA GINEE.—Tue ARROW-GRASS TRIBE. 
_ 1831. Triglochin maritimum, Linn. Arrow-grass. July. g 
18 i. %. Salt marshes usually. West to Mich. Bk 

CCLX. PISTIACEZ.—Tue puckweEeEp TRIBE. 
1532, Lemna trisulca, Linn. Duck’s meat. Ivy-leaved duck- 
weed. nite Floating and submersed, detached. 
6 lines. . pl. Ky. Sé. Miami country. 
1533. L. ee Linn. Duckweed. June-July. Float- 
ing, detached. 3to4 lines. ©.pl. Mich. Eat. O. 
4934. L. minor, Linn. Lesser duckweed. Water flax-seed. 
June-July. Floating, detached. 1 to2lines. ©. 
pl. O. Ky. 
