Echinodorus

Echinodorus, commonly known as burhead, is a genus of plant in the family Alismataceae. It contains a single species, Echinodorus berteroi, which is native to the Americas. The name is derived from Ancient Greek '''' 'rough husk', and '''' 'leathern bottle', alluding to ovaries, which in some species are armed with persistent styles, forming prickly head of fruit.

==Description== The plants are annual or perennial, growing emersed, floating-leaved, or seasonally submersed, leaves glabrous to stellate-pubescent; rhizomes present or absent; stolons absent; corms absent; tubers absent. Roots not septate. Leaves sessile or petiolate; petioles triangular, rarely terete; blade with translucent markings as dots or lines present or absent, linear to lanceolate to ovate, base attenuate to cordate, margins entire or undulating, apex obtuse to acute. Inflorescences racemes or panicles, rarely umbels, of 1–18 whorls, erect or decumbent, emersed; bracts coarse, apex obtuse to acute, surfaces smooth or papillose along veins, apex obtuse to acute. Flowers bisexual, subsessile to pedicellate; bracts subtending pedicels, subulate to lanceolate, shorter than to longer than pedicels, apex obtuse to acute; pedicels ascending to recurved; receptacle convex; sepals recurved to spreading, herbaceous to leathery, sculpturing absent; petals white, entire; stamens 9–25; filaments linear, glabrous; pistils 15–250 or more, spirally arranged on convex receptacle, forming head, distinct; ovules 1; style terminal or lateral. Fruits plump, often longitudinally ribbed, sometimes flattened, rarely abaxially keeled, abaxial wings absent, lateral wings absent, glands often present.