Potamogeton.| CYPERACEAE. 459 
drupe -like, more or less compressed. Seeds curved or cochleate, the thick 
radicular end of the embryo pointing downward. — Fresh-water weeds 
with jointed rooting stems and 2-ranked pellucid leaves which are alternate 
or rarely oppos osite, the “uppe r ones sometimes dilated, of a firmer texture, 
i t 
leaf. Spikes sheathed by the stipules in the bud, raised on a peduncle 
Leaves broad Poet Z : i z : : : : : - P. flui 
Leaves riarrow linear 2, P. ati ee 
1. P, fluitans, Roth, Tent. FL Germ. : 79, ~ ane nae. Floating leaves 
oes or lanceolate-oblong, s obtuse, tapering at the base, charta- 
ceous, with a prominent rib and 5-7 obscure parallel nerves on each side, 
2—31/2/ & 7—14”, on petioles of 11/2—3'/2‘, which are convex above. 
Submersed leaves alternate, lanceolate or linear, thin pellucid. Stipules 
connate, free from the petiole, lanceolate-acute, tess than 1‘. Peduncles 
l'/2—21/2’, terete, thicker than the stem, the spike 6—9“, cylindrical. 
Nutlets laterally compressed, with somewhat acute margins. — P. Owar- 
“shh Cham. in Linnaea, II, 228. — P. natans, var. angustatus, Kunth, 
. > 128. 
In «taro»-ponds and watercourses of Nuuanu! and elsewhere. “i species is widely 
knead’ over Europe, Asia, Africa, and N. America with the W. Indie 
2. P, pauciflorus, rey EL I, 121. — Kunth, Enum. Pl. IIL 136. — Stem 
slender, thread-like, flattish, forking from the base. Leaves all alike and 
submersed, alternate, sessile, narrow-linear, grass-like, 3- or 1-nerved, 
| ree iene and 1/;—1“ broad. Stipules connate, free from the leaf, 
clasping the stem, 3—5” long. Peduncles 3—5“, compressed, thicke ag 
above, reversed after flowering. Spikes very short, subglobose, 1/3—*/s' 
in diameter, 4—6-flowered. Nutlets semilunar, compressed, distinctly 
crested with 1 or 3 keels on the broad convex back, the short style 
oblique, almost incl Seed curved. — Cham. in Linnaea, II, 176, tab. 4, 
Heat Honolulu! in ponds and «taro»-patches. A North American species. 
H. — gree also P. Ga magebondt Cham., which is bse g be P. lucens, L., 
by Kun . p. 132, but a refere to his quotation (Linnaea 99) s! canted that 
Mahone Ss Bieat was collected on oe island of Guam or r Guajan ze ra Ladron 
Orper XCIV. CYPERACEAE. 
Flowers hermaphrodite or unisexual, in re consisting of several 
seale-like bracts called glumes, distichous or imbri e all round, with one 
flower in the axil of each, or the lower ones sole Perianth either 
wanting or replaced by bristles or scales. Stamens usually 3, but some- 
times more (4—6) or fewer. Ovary 1-celled, with a single erect anatropous 
ovule, in fruit forming an achenium. Style 3-cleft when the achene is 
