Flora of North America species comparison

erect to repent or prostrate, axis sympodial or monopodial, sometimes branching.

linear-attenuate, 5–30 cm, apex subulate.

mostly many ranked in rosettes, sometimes in loose spirals, mostly grasslike;

blade linear to linear-triangular, lingulate, tapering, base mostly clasping;

veins parallel.

scape sheaths mostly longer than principal leaves, loose;

scapes linear, 1–3 mm wide, multiribbed (ribs lacunar);

heads chalk white except for dark gray or near black exserted tips of receptacular bracts, anthers, hemispheric to subglobose, 10–20 mm wide, soft, much flattened when pressed;

receptacle pilose;

involucral bracts frequently squarrose, later obscured by mature bracteoles and flowers, gray, broadly ovate to oblong or elliptic, 2–3 mm, margins entire, apex rounded or obtuse, glabrous;

inner bracts, receptacular bracteoles dark gray, spatulate-linear to oblong, 2–3 mm, margins entire, apex acute with white, club-shaped hairs.

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.

(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.

sepals 2, pale or with dark apex, linear or linear-spatulate, 2–4 mm, apex acute to blunt with mealy white, club-shaped hairs;

androphore broadly club-shaped;

petals 2, pale, oblong, conspicuously unequal, larger lobe apically fringed with pale, club-shaped hairs, smaller lobe glabrous or with a few hairs at apex;

stamens 3–4(–6);

anthers black.

sepals 2, dark at apex, oblong-spatulate, 2.5–3 mm, abaxially with mealy white, club-shaped hairs, adaxially with translucent hairs;

petals 2, pale, oblong-spatulate, apex acute, abaxially with mealy white, club-shaped hairs, adaxially with translucent hairs;

pistil 2-carpellate.

capsules, thin-walled, loculicidal.

dark lustrous brown, broadly ovoid to near round but asymmetric, 0.5 mm, mostly minutely spiny-papillate.

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.

rhizomes or stems, thickened, short to variously elongate;

roots fibrous, spongy, or spongy-septate (diaphragmatic).