458 
ment bearing a2 to 4-celled anther; the fertile of 2 to 5 sessile pistils 
(in a cup-shaped involucre) forming obliquely oblong nutlets which are 
beaked with the short style, and a disk-like or 2-lobed stigma. 
1, Z. palustris L. Stems leafy: leaves 2 to 7 em, long: style at least half as long 
as fruit: fruit flattish, somewhat incurved, even or occasionally more or less toothed 
on the back, nearly sessile.—Slow-running streams and stagnant waters of western 
rT 
Texas. 
4.NAIAS L. (NAIAD.) 
Slender branching herbs, with opposite linear spinulose-toothed 
sessile leaves (dilated at base), very small solitary dicecious or monce- 
cious flowers sessile in the axils; the sterile consisting of a single 
stamen inclosed in a little membranaceous spathe (filament at first 
short); the fertile consisting of a single ovary tapering into a short 
style, 2 to 4 subulate stigmas, and the fruit a little seed-like nutlet 
inclosed in a loose separable membranaceous epicarp. 
1. N. flexilis Rostk. & Schmidt. Stems usually very slender: leaves very nar- 
rowly linear (1.5 to 2.5 em. long), very minutely serrulate : fruit3 mm. long, narrowly 
oblong: seeds lance-oval, smooth and shining.—Ponds and slow waters, western 
Texas. Var. ROBUSTA Morong has a stout few-leayed sparsely branching elongated 
stem and flat abruptly acute leaves. 
ERIOCAULER. (PIPE-wort FAMILY.) 
Aquatic or marsh herbs (stemless or short-stemmed), with a tuft of 
fibrous roots, a cluster of linear loosely cellular grass-like leaves, naked 
(sheathed at base) scapes bearing dense heads of moncecious (rarely 
diweious) small 2 or 3-merous flowers each in the axil of a scarious 
bract, chaffy double perianth (in ours), introrse anthers, and a 2 or 
3-celled 2 or 3-seeded pod. 
1. BRIOCAULON L. (Pire-worrt.) 
Acaulescent, with mostly smooth pellucid flat or concave (above) 
leaves, scapes or peduncles terminated by an involucrate single head 
of monecious and androgynous white-bearded or woolly flowers; the 
sterile with a calyx of 2 or 3-keeled or boat-shaped sepals, tubular 2 or 
3-lobed corolla (each lobe with a black gland or spot), twice as many 
stamens; the fertile with often remote calyx, 2 or 3 separate narrow 
petals, 2 or 3-lobed ovary, 1 style, 2 or 3 slender stigmas, and a mem- 
branaceous loculicidal pod. 
* Receptacle smooth. 
1. BE. articulatum Morong. Leaves short (2 to 7cm, long), acuminate, fenestrate, 
usually equaling the sheath: scapes weak, 4 to 7-striate, smooth, 5 to 15 em. high 
(or when submersed becoming 3 to 20 dm. high): heads 4 to 6 mm. broad: involu- 
eral seales obtuse: bracts cuneate or obovate, abruptly pointed, white-bearded: 
flowers densely bearded, the fertile about half as large as the sterile. (4. seplangulare 
With.)—Still waters and ponds throughout Texas. 
