Herbs perennial or annual. Leaves in a rosette, grasslike, linear, occasionally thinly filiform, often thin and transparent, fenestrate, base sheathing. Inflorescences capitate, globose to ovoid; scapes thin, twisted, angled, base surrounded by a bladeless, tubular sheath. Flowers 2- or 3-merous, bracteate, with both sexes usually in same head. Male flowers: sepals 2 or 3, connate or free; petals 2 or 3, often inconspicuous; stamens 6. Female flowers: sepals 2 or 3, free or connate; petals absent to 4, free; ovary (1--)3-loculed; ovules 1 per locule, basal; style 1, 1--3-branched. Fruit a capsule, thin, loculicidal. Seeds small; testa usually reticulate and prickly; endosperm with abundant starch grains.
Herbs, annual or perennial, cespitose or solitary, rosulate, rarely caulescent, mostly scapose, glabrous or variously pubescent with simple or compound hairs. Rootstocks rhizomes or stems, thickened, short to variously elongate; roots fibrous, spongy, or spongy-septate (diaphragmatic). Stems erect to repent or prostrate, axis sympodial or monopodial, sometimes branching. Leaves mostly many ranked in rosettes, sometimes in loose spirals, mostly grasslike; blade linear to linear-triangular, lingulate, tapering, base mostly clasping; veins parallel. Inflorescences terminal and/or axillary, simple [compound], involucrate [proliferative], buttonlike or short-cylindric; scape sheaths spathelike, tubular, enclosing scape base, distally open; scapes 1--many, simple [compound], terete, usually twisted, mostly multiribbed; involucral bracts spirally imbricate series, usually chaffy or scarious, grading inward to receptacular bracts or these absent; receptacle glabrous or variously hairy. Flowers (florets) unisexual, staminate and pistillate on same [rarely different] plants, radially or bilaterally symmetric; sepals 2--3, distinct or variously connate, diverging from stipelike base or merely part of lobeless column; petals 0 or 2--3, diverging from short to elongate stipe (part of androphore or gynophore) or merely part of lobeless column; stamens 2--4(--6), often unequal; filaments arising from floral axis, rarely epipetalous; anthers mostly black, 1--2-locular, 2--4-sporangiate, versatile or basifixed, dehiscence longitudinal; pollen 1-grooved, 3-nucleate; appendages present in some flowers, glandlike or peglike, rarely bladelike, sometimes fringed or variously cleft; pistil compound, 2--3-carpellate; ovary superior, raised on gynophore, 1 locule per carpel; ovules 1 per locule, adaxial-apical, pendulous, orthotropous, bitegmic; style terminal, appendaged or unappendaged, 2--3-branched, branches simple or apex rebranched. Fruits capsules, thin-walled, loculicidal. Seeds translucent, ovoid, ellipsoid, or broadly fusiform, mostly 1 mm or shorter, variously ribbed or sculptured; endosperm copious, mealy-starchy, with compound starch grains; embryo apical.
Fruit a membranous loculicidal capsule; seeds relatively large, testa generally scabrid or papillose; endosperm copious
Ovary 2-3-locular, ovules solitary, pendulous in each loculus; style usually distinct, divided above into 2-3 elongate, simple (or occasionally bifid) stigmas, sometimes with alternating appendages
Stamens equal in number to, or twice as many as the inner perianth segments; anthers 2-thecous, or less often 1-thecous, introrse
Inflorescence an involucrate capitulum comprising numerous small, densely crowded flowers often subtended by floral bracts; peduncle leafless, unbranched, usually arising from a well-developed basal sheath; flowers unisexual, the males and females mixed in the same capitulum, or the males in the middle and the females around, or rarely males and females in separate capitula; perianth membranous or scarious, the segments usually in 2 distinct series, the outer segments ("sepals") generally free in female flowers, often connate in male, the inner ("petals") free or rarely connate in female flowers, connate and often very reduced in male flowers
Annuals or perennials; stems often very short, occasionally elongate; leaves narrow, often crowded or rosulate, frequently with large, conspicuous cells
Annual or perennial herbs usually under 1 m. high, often much smaller; stem usually abbreviated to a basal disc, infrequently elongate
Fruit a thin-walled, loculicidally dehiscent capsule, each locule containing a single seed
Female flowers with a superior 2–3-locular ovary; style simple, tipped with 2, 3 or 6 elongate stigmas
Male flowers with stamens as many or twice as many as the sepals; inner whorl epipetalous; a vestigial gynoecium usually present
Leaves narrow, lanceolate to filiform, spirally arranged, crowded into a basal rosette or rarely dispersed on elongate stems, opaque to translucent, sometimes fenestrate
Inflorescence capitate, single or in umbels, on leafless ribbed scapes
Capitula composed of many small (often tiny) unisexual flowers on a central receptacle surrounded by 1–several whorls of involucral bracts, monoecious, each flower often subtended by a floral bract
Flowers trimerous or less often dimerous, subactinomorphic to strongly zygomorphic
Perianth usually composed of two distinct whorls, sometimes reduced or absent; calyx of free, partially or almost completely connate sepals, sometimes spathe-like especially in the male flowers; petals free or partially connate, spathulate to filiform, frequently hairy, often with a subapical black gland; male petals often fused with the floral axis to form an infundibular structure topped by very small free lobes
Kral, R. 1966. Eriocaulaceae of continental North America north of Mexico. Sida 2: 285--332. Kral, R. 1989. The genera of Eriocaulaceae in the southeastern United States. J. Arnold Arbor. 70: 131--142. Moldenke, H. N. 1937. Eriocaulaceae. In: N. L. Britton et al., eds. 1905+. North American Flora.... 47+ vols. New York. Vol. 19, pp. 17--50. Tomlinson, P. B. 1969. Eriocaulaceae. In: C. R. Metcalfe, ed. 1960+. Anatomy of the Monocotyledons. 8+ vols. Oxford. Vol. 3, pp. 146--192.