14. J. ténuis, Willd. Stem wiry (9–18´ high); leaves flat or channelled; panicle shorter than the involucral leaves, loose, or rarely crowded; flowers green (2´´ long or more); sepals lanceolate, very acute, spreading in fruit, longer than the ovoid retuse scarcely pointed green capsule; anthers nearly equal to the filaments; style very short; seeds small (about ¼´´ long), delicately ribbed and cross-lined.—Fields and roadsides, very common. (Eu.)—Var. secúndus, Engelm.; flowers smaller, secund along the incurved branches. N. Eng. to Penn. and Del.—Var. congéstus, Engelm.; branches contracted into a head and the flowers darker-colored. Minn. and westward.
15. J. dichótomus, Ell. Stems rigid (1½–2° high) from a tumid base; leaves filiform, nearly terete, slightly grooved on the inner side; panicle loose, often with 1-sided forked branches, mostly longer than the involucral leaf; flowers greenish (2´´ long or more); sepals lanceolate, sharp-pointed, spreading in fruit, as long as the globular beaked light mahogany-colored capsule; anthers nearly as long as the filaments; style short; seeds small ({1/5}–¼´´ long), coarsely cross-lined.—Low sandy grounds, N. J. to Fla.
16. J. Gerárdi, Loisel. (Black-Grass.) Stems scarcely flattened, rigid (1–2° high); panicle contracted, usually longer than the bracteal leaf; flowers chestnut-brown with green (1¾´´ long); sepals oval-oblong, obtuse, incurved, as long as the oval obtuse and mucronate capsule; anthers much longer than the short filaments; style as long as the ovary; seeds (nearly {1/3}´´ long) obovate, delicately ribbed and cross-lined.—Salt marshes; common along the coast and in W. New York; rare about the Great Lakes. (Eu.)
[+][+] Stems branched, diffuse, leafy; root annual, fibrous.
17. J. bufònius, L. Stems low and slender (3–9´ high), leafy, often branched from the base; panicle spreading, mostly with one-sided dichotomous branches; flowers remote, greenish (2–3½´´ long); sepals linear-lanceolate, awl-pointed, the 3 outer much exceeding the inner and the oblong obtuse capsule; stamens short; filaments scarcely longer than the anthers, seeds elliptical, obtuse ({1/5}–{1/6}´´ long).—Low grounds, by roadsides; common. (Eu.)
§ 3. Stems leafy; leaves terete or laterally flattened, more or less distinctly knotted by internal transverse partitions; panicle terminal, with flowers chiefly in heads.—Knotty-leaved Junci.
[*] Seeds barely pointed, not caudate.
[+] Flowers solitary or 2 together, panicled; stamens 6.
18. J. pelocárpus, E. Meyer. Stems slender and erect from a slender running rootstock (6–18´ high), bearing few thread-like slightly knotted leaves, branching above into a compound spreading panicle, bearing the flowers in the forks and along one side of the branches; often with the flowers or in place of them are tufts of leaves; flowers small (1–1¼´´ long), greenish with red; sepals oblong, obtuse, the 3 inner ones longer, but shorter than the oblong taper-beaked, 1-celled capsule; anthers much longer than the filaments; style slender; seeds (¼´´ long) obovate, short-pointed.—Sandy, wet or swampy places, Newf. to Fla., west along the Great Lakes to Minn. The proliferous plants are usually sterile and much larger, with larger diffuse panicles.—Var. súbtilis, Engelm. Creeping or floating, with a single pair of flowers at the end of the short stems.—Somerset Co., Maine (C. E. Smith); Canada.
[+][+] Heads numerous, of 3–12-flowers (rarely more); in early summer.