Fimbristylis dichotoma
Fimbristylis caroliniana
fork fimbry
Carolina fimbry
wand-like, at least 50 cm.
nearly distichous, spreading to ascending, 1/2 length of culms;
sheaths distally ciliate, backs mostly glabrous;
ligule line of short hairs;
blades narrowly linear, 2–3 mm wide, flat to broadly involute, scabridciliate, adaxially smooth or hirtellous.
nearly distichous, spreading to ascending, 1/2 length of culms, sheath margins ciliolate at junction with blade, backs smooth to pubescent;
ligule present, usually complete;
blades linear, 2–5 mm wide, flat to involute, margins scabridulous, surfaces mostly glabrous.
anthelae compound, dense or open, ascending-branched, longer than broad;
scapes slender, 1 mm wide, slightly compressed distally;
proximalmost involucral bract exceeding anthela.
anthelae compound, dense or diffuse, mostly longer than broad;
scapes wandlike, broadly linear, distally usually compressed, marginal ribs scabrid distally;
longest primary involucral bract exceeding or shorter than anthela.
pale drab brown to chestnut brown, ovoid-lanceoloid, 4–8 mm;
fertile scales broadly oblong or ovate, 2 mm, acute to obtuse angled, glabrous, midrib reaching scale tip or excurrent, finely mucronate.
pale brown or red-brown, broadly ovoid, ellipsoid, or lanceoloid, 5–15 mm;
fertile scales ovate, 3–4 mm, apex rounded, often puberulent distally, midrib excurrent as scabrid mucro or short cusp.
stamens 1–2;
styles 2-fid, flat, fimbriate.
stamens 3;
styles 2-fid, flat, fimbriolate.
white to brownish, lenticular, obovoid, 1–1.2 mm, cancellate, each face longitudinally with (5–)10–12 ribs, connected by vertical rows of horizontally rectangular pits.
pale to deep brown, lenticular-obovoid, 1 mm, finely but definitely cancellate with 14–15 horizontally oriented lattices per side.
= 20, 30.
= 20, 30, 60.
Fimbristylis dichotoma
Fimbristylis caroliniana
Fimbristylis dichotoma is found in temperate to tropical regions worldwide. It is one of the most widespread and weedy species of Fimbristylis, unquestionably with many races and forms. The two commonest forms in the United States often occur in mixed populations, one sort with inflorescence branches more ascending, inflorescence dense, habit lower, and leaves broader; the other sort usually taller, inflorescence more sparse, branches more widely spreading, and leaves more ascending and narrower. The abundance of such plants both in regions where rice originated and in regions where rice is, or was, introduced, indicates an Asian origin for such weeds.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
The tallest, coarsest plants of Fimbristylis caroliniana, formerly referred to as F. harperi Britton ex Small, are the most clonal of North American Fimbristyloids, some clones literally covering acres of sandy swale or beach.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
LA Plants
WildflowerSearch
iNaturalist
USDA Plants Database
MD Biodiversity
