The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

spike bentgrass

Habit Plants perennial, sometimes flowering in the first year, 8–100(150) cm tall, slightly glaucous; usually cespitose, rarely rhizomatous.
Leaves

ligules (1)1.7–8(11.2) mm, truncate to obtuse;

blades 4–15(25) cm × 2–7 mm; flat.

Inflorescences

(3)5–30 × 0.5–4 cm, contracted; spike-like, usually dense, sometimes interrupted near the base, bases usually exserted from the upper sheaths at maturity; lowest node with 1–5 branches;

branches ascending to appressed;

spikelet-bearing to or near the base, usually hidden by the spikelets; lower branches 1–2(4) cm.

Spikelets

crowded.

Glumes

1.5–3.5 mm, scabrous on the midvein and sometimes on the back, 1(3)-veined;

tips acute or long-acuminate, with an awn-like tip to 1 mm.

Calluses

with sparse to abundant hairs up to 0.3 mm.

Lemmas

1.2–2.2 mm; smooth, 5-veined;

veins sometimes extended as teeth to 0.1 mm;

tips acute; entire to toothed; awnless or awned;

lemma awns 0–3.5 mm, arising from above mid-length; straight or bent.

Paleas

absent or to 0.5 mm.

Lodicules

0.3–0.5 mm.

Anthers

3, 0.3–0.6 mm.

2n

=28, 42, 56.

Agrostis exarata

Distribution
[WildflowerSearch map]
[BONAP county map]
Discussion

Moist ground, streamsides, ditches, sand bars, lake margins, also seasonally moist disturbed spots in grasslands, shrublands, and forest openings, including coastal sites. 0–2700m. Throughout Oregon. CA, ID, NV, WA; throughout North America except midwest; Eurasia. Native.

Agrostis exarata is a common plant of wet, often disturbed habitats. It is variable in size, glume shape, and other details but can be recognized by its dense, narrow inflorescences and tiny anthers. This species can be difficult to separate from two closely related taxa, A. densiflora and A. microphylla. For both of these, habitat is an important clue for identification. Agrostis densiflora is a short plant of coastal sands and bluffs, while Agrostis microphylla is a vernal pool annual.

Source Flora of Oregon, volume 1, page 351
Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa
A. canina, A. capillaris, A. castellana, A. densiflora, A. exarata x Agrostis pallens, A. exarata x Agrostis stolonifera, A. gigantea, A. hallii, A. hallii x Agrostis pallens, A. hendersonii, A. howellii, A. idahoensis, A. microphylla, A. oregonensis, A. pallens, A. scabra, A. stolonifera, A. variabilis
Synonyms Agrostis ampla, Agrostis exarata ssp. exarata, Agrostis exarata ssp. minor, Agrostis exarata var. exarata, Agrostis exarata var. minor, Agrostis exarata var. monolepis, Agrostis longiligula
Web links