.- 



PONTEDERIACE.*. (PICKEREL-WEF.D FAMILY.) 483 



*- - Head single (or sometimes 2 or 3) : leaves channelled above : stamens 6. 



15. J. Stygius, L. Stem slender, erect (6' -10' high), 1 -3-leaved below, 

 naked above ; leaves thread-like ; heads 3 - 4-flowered, about the length of the 

 sheathing scarious awl-pointed bract; sepals oblong and lanceolate, scarcely- 

 more than half the length of the oblong acute pod; seeds oblong, with a very- 

 loose coat prolonged at both ends. Peat-bog bordering Perch Lake, Jefferson 

 County, New York. (Eu.) 



16. J. trifidUS, L. Stems densely tufted from matted creeping rootstocks, 

 erect (5'- 10' high), wiry and thread-like, sheathed at the base, leajless below, about 

 3-leaved at the summit ; the upper thread-like leaves subtending the sessile head 

 of 2 -4 flowers; sepals ovate or oblong, acute, rather than the globose-ovate 

 beak-pointed (brown) pod; seeds roundish, angled. Alpine summits of the 

 mountains of N. New England and N. New York, and high northward. (Eu.) 

 * H- -t- flowers ci/mose-panicled, separate (not clustered in heads) : leaves channelled 



or involute, or else thread-form, or almost setaceous : stamens 6. 



17. J*. tennis, Willd. Stems slender, wiry (9'- 18' high), simple, leafy 

 only near the base ; cyme shorter than the involucral leaves, small, the flowers 

 mostly one-sided, almost sessile, green and shining ; sepals lanceolate, very acute, 

 one third longer than the globose-ovoid obtuse pod. Low grounds and fields ; very 

 common. 



18. J. Greeiiii, Oakes & Tuckerm. Stems rigid (l-2high), simple, 

 naked, 1 - 2-leaved at the base ; cyme much shorter than the principal erect involucral 

 leaf, dense, the numerous crowded flowers one-sided ; sepals lanceolate, acute, 

 greenish, shorter than the ovoid-oblong obtuse pod. Sandy coast of Long Island 

 and New England, and occasionally on river-banks in the interior. 



19. J. bulbostlS, L. (BLACK GRASS.) Stems simple, somewhat flattened, 

 slender, but rigid (1 2 high), leafy below ; panicle somewhat cymose, rather 

 crowded, usually shorter than the bracteal leaf; sepals oval-oblong, obtuse, incurved, 

 chestnut-color and greenish, mostly rather shorter than the oblong-oval and 

 somewhat triangular obtuse mucronate pod. (J. cornpressus, Jaeq. : a name 

 with which some supersede the Linncean, because the stem is really not bulbous 

 at the base.) Var. GERARDI (J. Gerardi, T^oisel., and J. Bothuicus, Wald.) is 

 the more common form in this country, with the panicle usually exceeding the 

 bract, and the calyx as long as the pod. Salt marshes; common along the 

 coast from New Jersey northward. (Eu.) 



20. J. bufoilillS, L. Annual; stems low and slender (3' -9' high), leafy, 

 often branched at the base ; panicle forking, spreading ; the flowers remote, greenish ; 

 sepals lanceolate, awl-pointed, much longer than the oblong obtuse pod. Low 

 grounds and road-sides, everywhere. (Eu.) 



ORDER 129. PONTEDERIACEJE. (PICKEREL-WEED FAM.) 



Aquatic herbs, with perfect more or less irregular flowers from a spathe ; 

 the petal-lllce (i-uierou.i perianth free from the. 3-ccllcd oraru : the 3 or G most' 

 /,/ unequal or tKxsiwitfw st(tm':ns inserted in tin throat. Perianth with the 6 



