36 
notch of the face; style short, apical; embryo circle complete, the 
apex nearly touching the base a little inside of its end. 
A rare species growing in the shallow water of ponds. Round 
Pond, York, Me. (Fernald) ; Franconia Notch, N. H. and a small 
pond on Mt. Willey, 3,000 feet alt. (Faxon); Uxbridge, Mass. 
(Robbins, Morong); New York (Torrey); common іп N. J.; Great 
Lake, Carbon Co., Pa. (Porter). (Plate XLII.) 
19. POTAMOGETON CURTISSII, Morong, Bull. Torr. Bot. Club, xiii. 
145 (1886). 
Stems simple or branched, capillary, a foot or more in height, 
the internodes long and naked. Leaves 6-17 lines long, almost 
setaceous, many of them less than М of a line and none % a line 
broad, tapering to a long, hair-like point, the midrib with 2 deli- 
cate nerves or a loosely-reticulated space on each side of it. 
Stipules hyaline, obtuse, 3 or 4 lines long, deciduous. Peduncles 
3-6 lines long, somewhat clavate, erect, axillary and racemosely 
disposed, 5 or more of them at intervals of one or two inches 
along the upper part of the stem. Spikes capitate, 2 or 3 lines 
long, 3-6-flowered. Fruit not seen. 
Collected by Mr. A. H. Curtiss in Blackwater River, and a 
“tidal creek” in Northwest Florida, May and June, 1886, the only 
known locality for it. (Plate XLIII. A magnified leaf is figured 
on the right.) 
20. POTAMOGETON CRISPUS, L. Sp. Pl. 126 (1753). 
Stems branching, compressed. Leaves 2-ranked, linear-oblong 
or linear-oblanceolate, sloping at base, sessile or semi-amplexicaul, 
obtuse, serrulate, crisp, 34—4 inches long and 3-7 lines wide, 3-7- 
nerved, the midrib often compound and the outer nerves very near 
the margin. Stipules small, scarious, obtuse, early perishing. 
Peduncles 1-2 lines long, frequently recurved when in fruit and 
sometimes very numerous. Spikes about half an inch long, and 
looking very bristly with the long-beaked drupes when in fruit. 
Fruit ovate, about 114 lines long and 1 line or a little more in 
width, having 3 rounded keels on the back, the middle one with a 
small projecting tooth near the base, a slightly curved face, and a 
curved facial style nearly as long as the drupe ; the shell thick and 
corky, containing a small embryo, the apex of which points 
directly towards the end of the radicle. 
