POND WEED FAMILY 73 



13. P. compressus L. Eel-geass Pondweed. Stem very much flattened; 

 foliage brisjht green and shining; leaves fascicled at summit of the branches, 

 with numerous fine nerves, 2 to 6 inches long, I14 to 2 lines wide, abruptly 

 acute, mucronate. sessile; stipules scarious, soon perishing; spikes 14 to 1 inch 

 long, on peduncles 1 to 4 inches long ; nutlet nearly or quite 2 lines long, 

 3-keeled on back. 



Honey Lake Valley, Lassen Co., Davy 3356; Oregon to British roluinbia and 

 east to New Jersey and New Brunswick. Eiu'ope. 



Eefs. — POTAMOGETOX coMPREssus L. Sp. PI. 127 (17.'5?.); Hegi, 111. Fl. Mittel-Europa, 1: 

 132, fig. 60 (1906). P. zosteraefoVms Sebum. Enum. PI. Saell. 1: .50 (1801); Morong, Mem. 

 Torr. Club, 3=: 37, pi. 4.5 (1893). 



14. P. pectinatus L. Fennel Pondweed. Stems % or 2 to 6 or 8 feet long, 

 from a running rootstock, repeatedly forking above, then very leafy and form- 

 ing broom-like clusters ; leaves very slender, setaceous, 1 to 3 inches long 

 exclusive of the sheaths which are ^4 to % inch long or on the lower leaves 

 even 2 inches long ; scarious margin of the sheaths very narrow ; spikes i/o to 

 li/o inches long, the flowers in distinctly separated whorls; peduncles 1 to 3 or 

 more inches long ; nutlet li <> to 2 lines long, with an obscure ridge on each side 

 of the back. 



The most common species throughout the state from sea-level to 7000 feet 

 altitude. Beyond our borders of world-wide distribution. The rootstocks 

 imbedded in the mud of ponds bear tubers about the size of a pea. The deep- 

 diving ducks, such as the Canvas-back and Broad-bill, feed upon these sweet 

 nutritious tubers, pulling loose at the same time more or less of the tender 

 rootstocks and the attached stems which float to the surface and are shared 

 with the surface-feeding species like the Teal and Mallard. It is to this plant 

 that the Canvas-back, while living in the salt-marshes, owes the succulent and 

 nutty flavor of its flesh, making it in the eyes of sportsman and epicure superior 

 to every other kind of Californian wild-fowl. 



Eefs. — POTAMOGETON PECTINATUS L. Sp. PI. 127 (1753); "Wats. Bot. Cal. 2: 198 (1880); 

 Morong, Mem. Torr. Club, 3=: 51. pi. 58 (1893); Hegi, 111. Fl. Mittel-Europa, 1: 137, fig. 67 

 (1906); .lepson, Fl. W. Mid. Cal. 2a ed. 29 (1911). 



15. P. latifolius Jlorong. Near the preceding ; stems stoutish, white, branch- 

 ing; leaves numerous, fascicled terminally, i^ to ly^ lines broad; adnate por- 

 tion of stipule 1/4 to 1 inch long, broad on the uppermost leaves, scarious- 

 margined, the free portion shorter. 



Brackish water: Honey Lake Valley, Lassen Co., Davy 3357; Goose Lake, 

 Mrs. R. M. Austin, ace. Morong; also apparently at Gilroy. Northwestern 

 Nevada. 



Eefs. — POTAMOGETON LATIFOLIUS Morong, Mem. Torr. Club, 3': 52, pi. 59 (1893); Jepson, 

 Fl. W. Mid. Cal. 2d ed. 29 (1911). P. pectinatus var. (?) latifolius Bobbins, U. 8. Expl. 40th 

 Par. 5: 338 (1871), type loc. Humboldt River below Humboldt Lake, Nev.; Wats. Bot. Cal. 

 2: 198 (1880). 



16. P. robbinsii Oakes. Stems stout ; rootstocks running, sometimes nearly 

 1 foot long; leaves crowded in 2 ranks, liA to 4 inches long, li/o to 2 lines wide, 

 obtuse, mucronate, auriculate at jimction of free portion of stipule; adnate 

 portion of .stipules about % inch long, the free portion as long or longer. 



Honey Lake Valley, Lassen Co., Davy. Oregon to British Columbia, east to 

 Delaware and New Brunswick. 



Refs. — POTAMOGETON ROBBINSII Oakes, in Hovey, Mag. Hort. 7: 180 (1841); Morong, Mem. 

 Torr. Club, 3=: 54, pi. 61 (1893). 



