Achnatherum diegoense
Achnatherum coronatum
San Diego County needlegrass, San Diego needlegrass
crested needlegrass, giant ricegrass
110-140 cm tall, 2.5-4 mm thick, internodes densely and retrorsely pubescent for 3-9 mm below the nodes, particularly the lower nodes, glabrous or retrorsely puberulent elsewhere;
nodes 3, pubescent or glabrate.
55-210 cm tall, 3-6 mm thick, internodes usually glabrous, lower internodes sometimes puberulent;
nodes 1-2, glabrous.
21-25 cm long, (2)4-8 cm wide;
branches strongly divergent to ascending, straight, lower branches 5-7 cm.
15-60 cm long, 2-4 cm wide;
branches widely spreading to ascending, longest branches 4-13 cm.
appressed to the branches.
subequal, 8-11.5 mm;
lower glumes 0.5-1 mm wide, 3-5-veined;
upper glumes 3-veined;
florets 5.5-7.5 mm long, 0.7-1 mm thick, fusiform, terete;
calluses 0.25-1.2 mm, acute;
lemmas evenly hairy, hairs at midlength and at the apices 0.5-1 mm, apical lobes 0.2-0.4 mm, membranous, flexible;
awns 20-50 mm, persistent, twice-geniculate, all segments scabrous to scabridulous, terminal segment straight;
paleas 2.6-3.8 mm, 1/2 - 3/4 as long as the lemmas, pubescent, hairs not extending beyond the apices, veins terminating below the apices, apices rounded;
anthers 2.5-4 mm, dehiscent, not penicillate.
lanceolate, glabrous, tapering to awnlike apices;
lower glumes 16-21 mm long, 1-1.3 mm wide, midveins scabrous;
upper glumes 11-18 mm;
florets 6.5-10 mm long, about 1 mm thick, fusiform, terete;
calluses 0.5-2 mm, blunt to acute;
lemmas densely hairy, hairs at midlength 1.5-4 mm, apical hairs 2-5 mm;
awns 25-45 mm, persistent, twice-geniculate, all segments scabrous, terminal segment straight;
paleas 3.5-5.5 mm, 3/5 – 9/10 as long as the lemmas, sparsely hairy between the veins, apices flat, rounded;
anthers 3-4 mm, dehiscent, not penicillate.
5-7 mm, fusiform.
sheaths mostly glabrous or puberulent, margins ciliate distally;
collars glabrous or with hairs, hairs mostly to 0.5 mm, sides with tufts of 1.5-2 mm hairs;
ligules 0.4-2 mm, rounded to acute, abaxial surfaces hairy, hairs to 0.5 mm;
upper ligules 1-3 mm, similar in structure and pubescence;
blades 1-3.5 mm wide, abaxial surfaces smooth or scabrous, adaxial surfaces prominently ribbed, hairy, hairs 2-3 mm.
sheaths mostly glabrous, often puberulent on the lower portion, flat, ribbonlike with age, margins hairy distally, hairs 1-2.5 mm;
collars mostly glabrous;
ligules 0.4-1.6(3) mm, truncate to slightly rounded, abaxial surfaces pubescent, ciliate, cilia about 0.5 mm;
blades usually flat, 2.5-7 mm wide, both surfaces scabrous.
= unknown.
= 40.
Achnatherum diegoense
Achnatherum coronatum
Achnatherum diegoense grows in chaparral and coastal sage scrub, on rocky soil near streams or the coast, at 0-350 m, on the Channel Islands of Santa Barbara County, California, and, on the mainland, in Ventura and San Diego counties south into Baja California, Mexico.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Achnatherum coronatum grows on gravel and on rocky slopes, mostly in chaparral associations of the Coast Range from Monterey County, California, to Baja California, Mexico. It is similar in size to A. diegoense, but differs in its mostly glabrous internodes and longer paleas. It differs from A. parishii, an inland species, in its twice-geniculate awns, more robust habit, and more sparsely pubescent paleas. Occasional plants combine the characteristics of both species.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
WildflowerSearch
iNaturalist
USDA Plants Database
