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hot springs fimbristylis, hot springs fimbry

hurricanegrass

Habit Plants perennial, robust, 50–150 cm, cespitose or with culms solitary; rhizomes scaly, slender, elongate. Plants perennial, cespitose, (5–)10–60 cm, bases hard, glabrous; rhizomes absent.
Leaves

nearly distichous, spreading to ascending, 1/2 length of culms;

sheath margins entire, backs smooth to pubescent;

ligule present, complete;

blades narrowly linear, proximally flat, 2–3.5(–4) mm wide, margins scabrid-ciliate, abaxial surface sometimes pubescent.

polystichous, mostly spreading-excurved, to 1/2 as long as culms;

sheaths usually entire;

ligule absent;

blades linear, 2–3 mm wide, flat or shallowly involute, margin scabrid, apex blunt.

Inflorescences

anthelae simple or compound, longer than wide;

scapes wandlike, nearly terete or slightly compressed, distally 1 mm thick, marginal ribs scabrid;

longest primary involucral bract shorter than panicle.

simple or compound anthelae with numerous small pedunculate clusters of sessile spikelets;

scapes linear, distally terete, 1–2 mm thick;

involucral bracts short, usually shorter than inflorescence.

Spikelets

pale dull brown, lance-ovoid to cylindric-ellipsoid, 10–12 mm;

fertile scales ovate, 3.5–4 mm, apex broadly acute, ciliate, surface uniformly puberulent, midrib excurrent as mucro or cusp.

greenish brown or yellow-brown, ovoid, 2–3 mm;

fertile scales broadly ovate, 1–1.5 mm, obtuse or apically notched, midrib not excurrent.

Flowers

stamens 3;

styles 2-fid, flat, fimbriate.

stamens usually 1;

styles 2-fid, slender, glabrous.

Achenes

dark brown, lenticular-obovoid, 1.5 mm, finely cancellate, with 20 or more longitudinal rows of horizontally rectangular pits per side.

dark brown to nearly black, tumidly obovoid, rarely obscurely 3-ribbed, 1 mm, faintly striate to variously warty, faintly reticulate.

2n

= 20.

= 56.

Fimbristylis thermalis

Fimbristylis cymosa

Phenology Fruiting spring–fall. Fruiting all year.
Habitat Mineralized sands of hot springs, alkaline seep meadows Sands of sea beaches, brackish sandy open sites, often disturbed, commonly just in from mangrove or on sandy road shoulders
Elevation 300–600 m (1000–2000 ft) 0–50 m (0–200 ft)
Distribution
from FNA
AZ; CA; NV; UT; Mexico (Baja California, Coahuila)
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; s Mexico; Central America; South America; Africa; Asia; Indian Ocean Islands; Pacific Islands; Australia
[BONAP county map]
Discussion

New World examples of Fimbristylis cymosa are almost exclusively bicarpellate, with bifid styles; Old World Oceania examples are tricarpellate, with trifid styles, a form not covered in this treatment.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23, p. 124. FNA vol. 23, p. 128.
Parent taxa Cyperaceae > Fimbristylis Cyperaceae > Fimbristylis
Sibling taxa
F. annua, F. autumnalis, F. brevivaginata, F. caroliniana, F. castanea, F. cymosa, F. decipiens, F. dichotoma, F. miliacea, F. perpusilla, F. puberula, F. schoenoides, F. squarrosa, F. tomentosa, F. vahlii
F. annua, F. autumnalis, F. brevivaginata, F. caroliniana, F. castanea, F. decipiens, F. dichotoma, F. miliacea, F. perpusilla, F. puberula, F. schoenoides, F. squarrosa, F. thermalis, F. tomentosa, F. vahlii
Synonyms F. melanospora, F. obtusifolia, F. sintenisii, F. spathacea, Scirpus obtusifolius
Name authority S. Watson: Botany (Fortieth Parallel), 360. (1871) R. Brown: Prodr., 228. (1810)
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