Herbs perennial, aquatic, with linear, spongy, cellular leaves, sheathing at base. Flowers monoecious or dioecious, in a dense head. Perianth 2 to 6-parted or wanting. Stamens 6, some of them generally abortive. Anthers mostly 1-celled, in-trorse. Ovary 2 or 3-celled, cells 1-seeded. Seeds pendulous.
Genera 9, species 200, chiefly tropical. They are of no known use.
* Stamens (4 or 6) twice as many as the petals. (Scape 7 to 12-ribbed).......
* Stamens 3, as many as the petals. (Scape 5-ribbed, puberulent)......................................
* Stamens 3, and no petals. Scape 5-ribbed, short, hairy...................................................
1. ERIOCAU'LON, L. Pipewort. (Gr. wool, stem.) Flowers 8 , collected into an imbricated bead; involucre of many bracts;
in the disk (rarely mixed); perianth double; sepals 3, subregular; petals united to near the summit; stamens twice as many as the petals;
in the margin; perianth double; sepals 3, petals 2 or 3, distinct; stamens 0; ovary sessile or stipitate; style 1, stigmas 2 or 3; capsule 2 or 3-seeded. - Acaulescent. Lvs. grass-like, flat, tufted at the base of the slender, simple, one-headed, fluted scape. (Fls. 4-parted in one species.)
1 E. decangulare L. Scape tall, slender, marked with 10 ribs and furrows; lvs. linear-ensiform, suberect, half as long as the scape; bracts of the depressed involucre acute; chaff acuminate and tipped with a white fringe as well as the perianth. - Ponds, in pine barrens, S. States, common. Scape 1 to 3f high, very strict, clustered. Lvs. 6 to 16' high, 3 to 4" wide. Head 5" broad, very white with the fringes, the corollas tipped with black. Jl, Aug.
2 E. gnaphaloides Mx. Scape tall, slender, marked with 10 ribs and furrows; lvs. ensiform, subulate, many times shorter than the scape, spreading; invol. depressed; bracts obtusish; chaff acute, white fringed as well as the perianth. - Swampy pine barrens, N. J. to Fla., common. Scape mostly single, If to 30' high. Lvs. 2 to 4' long, 3 to 5" wide, gradually tapering to an acute or setaceous point. Head similar to No. 1. Jn. - Aug.
3 E. septangulare Withering. Scape slender, 7-furrowed, short or tall, and weak according to the depth of the water; lvs. linear-setaceous, pellucid, 5-reined, very short; head small, globular; bracts of the invol. obtuse. - In shallow water. Can. to N. J. and Mich. Sts. clustered, 3' to 3f, filiform, reaching the surface of the water. Lvs. in a small tuft, submersed. Head 2 to 3" diam., white with the fringes of the compact flowers. Jl, Aug.
2. PaePALANTHUS, Mart. (Gr. dust or powder, Flowers 3-parted; stamens in the sterile flowers 3; stigmas in the fertile flowers 3; capsule 3-secded. - Otherwise nearly as in Eriocaulon, from which the genus was separated.
P. flavidulus Kunth. Acaulescent, turfy; scapes numerous, filiform, 5-ribbed and furrowed, finely puberulent; lvs. linear-setaceous, many times shorter than the scapes; head globular; bracts of the involucre oblong, obtuse, straw-colored, dry; fls. not fringed. - Wet, sandy barrens, Va. to Fla. Sts. 6 to 9' high, lvs. 1 to 2'. Heads 3" diam. with a straw-colored in vol. and silvery white periantha Apr. - Jn. (Eriocaulon Mx.)
3. LACHNOCAU'LON, Kunth. (Gr. wool, .stem.)
Flowers and inflorescence as in Eriocaulon; calyx 3-sepaled; corolla 0; stamens 3; anthers 1-celled, filament united below; calyx 3-sepaled; corolla reduced to a tuft of hairs surrounding the 3-seeded ovary. - Habit of Eriocaulon.
L. Michauxii Kunth. Wet, sandy plains, Va. to Fla. Scapes 1 to 5' high, numerous, 5-ribbed, filiform, clothed with thin, spreading, woolly hairs. Lvs. linear-subulate, about 1' long, tufted. Head very small (L" diam.), globular, greenish-white. Apr., May. (Eriocaulon villosum Mx.)
FIG. 746-784. 1. Cyperus diandrus. 2 Spike-let magn. 3. A glume. 4. A flower. 5. Tri-chelostylis autumnalis. 6. Spike let. 7. Ovary with triple style. 8. Flower of T. capiilaris. 9. Ovary of T. stenophylla. 10. Rhynchos-pora alba. 11. Spikelet. 12. Ovary, seta?, etc. 13. Carex rosea. 14. Glume. 15. Peritryniuin. 16. C. flava. 17. Glume. 16. Perigyniuin.
Class IV. GLUMIFERae.
Plants of the endogenous structure, having the flowers invested with an imbricated perianth of alternate glumes instead of sepals and petals, and collected into spikelets, spikes or heads. The Class is equivalent to the
Cohort 7. GRAMINOIDEae.