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agrostide fine, browntop, colonial bent, colonial bentgrass, Rhode Island bent, Rhode Island bentgrass

colonial bentgrass, Idaho bent, Idaho bentgrass, Idaho redtop

Habit Plants perennial; rhizomatous or stoloniferous, rhizomes or stolons to 5 cm. Plants perennial; cespitose, not rhizomatous or stoloniferous.
Culms

10-75 cm, erect or geniculate, with 2-5 nodes.

8-40 cm, slender, erect, with 2-5 nodes.

Leaves

basal and cauline;

sheaths smooth;

ligules 0.3-2 mm, shorter than wide, dorsal surfaces usually scabridulous, sometimes smooth, apices truncate to rounded, erose-ciliolate, sometimes lacerate;

blades 3-10 cm long, 1-5 mm wide, flat.

mostly basal;

sheaths usually smooth, sometimes scabridulous, not inflated;

ligules (0.7)1-3.8 mm, dorsal surfaces scabridulous, apices rounded to truncate, rarely acute, erose to lacerate;

blades 1-7 cm long, 0.5-2 mm wide, flat, becoming involute.

Panicles

3-20 cm long, less than 1/2 the length of the culm, (1)2-12 cm wide, stiffly erect, widely ovate, open, exserted from the upper sheaths at maturity, lowest node with (2)3-9(13) branches;

branches smooth or scabridulous, spreading during and after anthesis, spikelets usually confined to the distal 1/2, lower branches 1.5-7 cm;

pedicels 0.4-3.3 mm, adjacent pedicels divergent.

3-13 cm long, 1-6(8) cm wide, lanceolate to ovate, diffuse, exserted from the upper sheaths at maturity, lowest node with 1-6(10) branches;

branches scabridulous, fairly stiff, more or less ascending, branching at or above midlength, spikelets not crowded, frequently solitary, lower branches 1-4 cm;

pedicels 0.5-6.4 mm.

Spikelets

lanceolate or oblong, purplish brown to greenish.

lanceolate to narrowly ovate, purplish.

Glumes

subequal, 1.7-3 mm, 1-veined, acute;

lower glumes scabridulous over the midvein towards the apices;

upper glumes scabridulous or smooth over the midvein;

calluses glabrous, or with a few hairs to 0.1 mm;

lemmas 1.2-2.5 mm, smooth, glabrous, opaque to translucent, 3(5)-veined, veins typically prominent, apices obtuse to acute, usually entire, sometimes the veins excurrent to 0.5 mm, usually unawned, rarely awned, sometimes varying within a panicle, awns to 2 mm, mid-dorsal, straight or geniculate;

paleas 0.6-1.2(1.4) mm, typically at least 1/2 the length of the lemmas, veins visible;

anthers 3, 0.8-1.3 mm.

subequal, 1.5-2.5 mm, 1-veined, usually scabrous to scabridulous, upper glumes sometimes smooth, apices acute to acuminate;

callus hairs to 0.3 mm, sparse;

lemmas 1.2-2.2 mm, usually smooth, sometimes scabridulous, translucent to opaque, 5-veined, veins usually prominent at least distally, sometimes obscure, apices acute to obtuse, entire, unawned;

paleas absent, or to 0.2 mm and thin;

anthers 3, 0.3-0.6 mm.

Caryopses

0.8-1.5 mm;

endosperm solid.

1-1.3 mm.

2n

= 28.

= 28.

Agrostis capillaris

Agrostis idahoensis

Distribution
from FNA
AK; AL; AR; CA; CT; DC; ID; IL; IN; KY; MA; MD; ME; MI; MO; MS; MT; NC; ND; NH; NJ; NV; NY; OH; OR; PA; RI; SC; TN; UT; VA; VT; WA; WV; WY; HI; BC; NB; NL; NS; ON; PE; QC; YT; Greenland
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AZ; CA; CO; ID; MT; NM; NV; OR; UT; WA; WY; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Agrostis capillaris grows along roadsides and in disturbed areas. It was introduced from Europe, and is now well established in western and eastern North America. It is often used for fine-leaved lawns; commercial seed sold as Agrostis tenuis 'Highland' usually contains A. capillaris.

Agrostis capillaris differs from A. gigantea (p. 641) in its short ligules, especially on the vegetative shoots, and the open panicles that lack spikelets near the base of the branches. It differs from A. castellana (see next) in having diffuse rather than clustered spikelets, fewer rhizomes, divaricate panicle branches after anthesis, calluses that are glabrous or with hairs up to 0.1 mm long, and glabrous lemmas. It also tends to flower somewhat earlier than A. castellana. Agrostis capillaris readily hybridizes with A. vinealis (p. 643), the hybrids being somewhat intermediate between the two parents.

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

Agrostis idahoensis grows in western North America, from British Columbia to California and New Mexico, in alpine and subalpine meadows along wet seepage areas and bogs, and in wet openings with Sphagnum in coniferous forests. It was recently discovered in Chile and Argentina; it is not known whether it is native or introduced there (Rugolo de Agrasar and Molina 1997). Agrostis idahoensis is often confused with A. mertensii (p. 644) and dwarf forms of A. scabra (p. 646), both of which tend to grow in better-drained habitats.

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

Source FNA vol. 24, p. 639. FNA vol. 24, p. 649.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Agrostis Poaceae > subfam. Pooideae > tribe Poeae > Agrostis
Sibling taxa
A. anadyrensis, A. blasdalei, A. canina, A. castellana, A. clavata, A. densiflora, A. elliottiana, A. exarata, A. gigantea, A. hallii, A. hendersonii, A. hooveri, A. howellii, A. hyemalis, A. idahoensis, A. mertensii, A. microphylla, A. nebulosa, A. oregonensis, A. pallens, A. perennans, A. rossiae, A. scabra, A. stolonifera, A. tolucensis, A. variabilis, A. vinealis
A. anadyrensis, A. blasdalei, A. canina, A. capillaris, A. castellana, A. clavata, A. densiflora, A. elliottiana, A. exarata, A. gigantea, A. hallii, A. hendersonii, A. hooveri, A. howellii, A. hyemalis, A. mertensii, A. microphylla, A. nebulosa, A. oregonensis, A. pallens, A. perennans, A. rossiae, A. scabra, A. stolonifera, A. tolucensis, A. variabilis, A. vinealis
Synonyms A. vulgaris, A. tenuis forma aristata, A. alba var. vulgaris, A. alba var. aristata, A. tenuis A. filiculmis, A. tenuis
Name authority L. Nash
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