Agrostis densiflora
Agrostis mertensii
California bent, California bent grass
agrostide de Mertens, Merten's bentgrass, northern bent, northern bentgrass
9-85 cm, erect, sometimes decumbent at the base, sometimes rooting at the lower nodes, usually with 4-7 nodes.
(5)10-40 cm, erect, with 2-4 nodes.
basal and cauline;
sheaths smooth or scabrous;
ligules 1-4.8(7.5) mm, dorsal surfaces scabrous, apices truncate to obtuse, erose-lacerate, sometimes ciliolate;
blades 2-12 cm long, 2-10 mm wide, upper blades broader than those below, flat.
mostly basal or basal and cauline, basal leaves persistent;
sheaths smooth or scabrous;
ligules 0.7-3.3 mm, scabridulous or smooth, usually rounded, sometimes acute or truncate, erose, sometimes lacerate;
blades 2.5-13 cm long, 0.5-3 mm wide, usually flat, occasionally involute or folded.
2-10 cm long, 0.5-2 cm wide, narrow and spikelike to dense, lobed-lanceolate, bases exserted or enclosed by the upper sheaths at maturity;
branches to 1.5 cm, scabrous, appressed, branching at the base and mostly hidden by the spikelets;
pedicels about 0.4-3 mm.
(2)3-10 cm long, (0.5)1.5-5 cm wide, widely ovate to lanceolate, usually open, exserted from the upper sheaths at maturity, lowest node with (1)2-5 branches;
branches erect, not capillary, readily visible, smooth or sparsely scabridulous, branched above midlength, spikelets in the distal 1/2 or beyond, lower branches (1.5)2-4 cm;
pedicels 0.4-6.4 mm.
lanceolate to narrowly ovate, yellowish, sometimes tinged with purple, or greenish purple.
lanceolate to narrowly ovate, dark brown or purplish.
generally equal, 2-3.3 mm, 1-veined, densely scabrous, aculeolate on the veins, narrowly acute to acuminate or somewhat mucronate, mucros to about 0.5 mm;
callus hairs to 0.3 mm, usually dense;
lemmas 1.5-2.1 mm, smooth or scabridulous, translucent, (3)5-veined, veins prominent to obscure, sometimes prominent only distally, apices acute to obtuse, veins usually extended as teeth up to 0.3 mm, unawned or awned from above midlength, awns to 3.5 mm, straight, readily deciduous;
paleas 0.3-0.7 mm, thin;
anthers 3, 0.5-2 mm.
subequal, 2-4 mm, elliptical to lanceolate, midveins scabrous to scabridulous, at least distally, 1-veined, acute;
callus hairs to 0.4 mm, sparse;
lemmas 1.6-2.6 mm, smooth or scabridulous, translucent to opaque, 5-veined, veins prominent to obscure, apices acute, entire or erose, awned from just below midlength, awns (2)3-4.4 mm, geniculate, exserted, persistent;
paleas absent, or to 0.1 mm and thin;
anthers 3, 0.5-0.8 mm, usually shed at anthesis.
1-1.5 mm;
endosperm solid.
1.4-2 mm;
endosperm solid.
= 42.
= 56 [reports of 2n = 42 are for Agrostis scabra].
Agrostis densiflora
Agrostis mertensii
Agrostis densiflora is endemic to coastal Oregon and California. It grows in sandy soils, on cliffs, and in scrublands. It appears to be related to A. exarata (see previous), and hybridizes with A. blasdalei (p. 656).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Agrostis mertensii grows on banks and gravel bars in river and lake valleys, and on open grasslands and rocky slopes of mountains and cliffs. It has a circumboreal distribution. In the Flora region, it extends from Alaska across Canada to Newfoundland and Greenland, south in the mountains to Wyoming and Colorado in the west, and West Virginia, Tennessee, and North Carolina in the east. It also grows in arctic Europe, Scandinavia, the mountainous regions of Mexico, and northwestern South America, where some unusually robust specimens have been somewhat dubiously referred to this species.
Agrostis mertensii is frequently confused with dwarf, awned forms of A. scabra (p. 646), but has larger spikelets, more culm nodes, larger anthers, slightly wider, flatter leaves, and panicles that are less expanded and less than lh the culm length. Agrostis mertensii is also often confused with A. idahoensis (p. 649), but A. mertensii tends to grow in better-drained habitats. Agrostis mertensii differs from A. anadyrensis (see next) in being less robust, having narrower, less abundant basal leaves, smaller panicles, and minor differences in the insertion of the awns on the lemmas. In addition, the panicle branches are smooth to weakly scabrous, contrasting with the branches of A. anadyrensis, which are strongly scabrous, with long acicules throughout their length.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
BC
WA
Go Botany
