Achnatherum diegoense
Achnatherum lobatum
San Diego County needlegrass, San Diego needlegrass
littleawn needlegrass, lobed needlegrass
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.
40-100 cm tall, 0.6-2.6 mm thick, glabrous or sparsely pubescent to 5 mm below the lower nodes;
nodes 4.
21-25 cm long, (2)4-8 cm wide;
branches strongly divergent to ascending, straight, lower branches 5-7 cm.
12-28 cm long, 0.5-1.5 cm wide;
branches ascending to appressed, straight, longest branches 3-6 cm.
appressed to the branches.
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.
unequal;
lower glumes 9.5-12.5 mm long, 0.8-1.2 mm wide, 3(5, 7)-veined, apices straight to somewhat recurved;
upper glumes 2-3.5 mm shorter, 3-veined;
florets 5.5-7.5 mm long, 0.6-1.1 mm thick, terete, widest about midlength;
calluses 0.3-0.5 mm, blunt;
lemmas evenly hairy, hairs at midlength 0.7-1.2 mm, fusiform, terete, apical hairs 1.3-2.2 mm, erect, usually less than 1 mm longer than those at midlength, apical lobes 0.5-1.2 mm, membranous, flexible;
awns 10-22 mm, persistent, once- or twice-geniculate, scabrous, terminal segments straight;
paleas 3-4.3 mm, 3/5 – 3/4 as long as the lemmas, pubescent, hairs exceeding the apices, veins terminating below the apices, apices flat, rounded;
anthers 3-4 mm, dehiscent, sparsely penicillate, hairs about 0.1 mm.
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 becoming flat and papery in age, margins sometimes ciliate distally, cilia to 0.5 mm;
collars, including the sides, glabrous or sparsely pubescent, collars of the flag leaves glabrous;
basal ligules 0.2-1.3 mm, membranous, truncate, erose to ciliate, cilia about 0.05 mm;
upper ligules 0.3-1 mm;
blades 1-4 mm wide, abaxial surfaces smooth, adaxial surfaces scabrous.
= unknown.
= unknown.
Achnatherum diegoense
Achnatherum lobatum
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 lobatum grows on rocky, open slopes in pinyon-pine and white fir associations of southern Arizona, New Mexico, Texas, and northern Mexico, at 2100-2800 m. It flowers from mid- to late summer.
Achnatherum lobatum is similar to A. scribneri and A. perplexum. It differs from A. scribneri in its shorter apical lemma hairs and blunt calluses, and from A. perplexum in having longer lemma lobes and erect apical hairs.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
WildflowerSearch
iNaturalist
USDA Plants Database
