Home Flora of Missouri
Home
Name Search
Families
Volumes
!Bromus commutatus Schrad. Search in The Plant ListSearch in IPNISearch in Australian Plant Name IndexSearch in NYBG Virtual HerbariumSearch in Muséum national d'Histoire naturelleSearch in Type Specimen Register of the U.S. National HerbariumSearch in Virtual Herbaria AustriaSearch in JSTOR Plant ScienceSearch in SEINetSearch in African Plants Database at Geneva Botanical GardenAfrican Plants, Senckenberg Photo GallerySearch in Flora do Brasil 2020Search in Reflora - Virtual HerbariumSearch in Living Collections Decrease font Increase font Restore font
 

Published In: Flora Germanica 1: 353. 1806. (Fl. Germ.) Name publication detail
 

Project Name Data (Last Modified On 7/9/2009)
Acceptance : Accepted
Project Data     (Last Modified On 7/9/2009)
Status: Introduced

 

Export To PDF Export To Word

1. Bromus commutatus Schrad. (hairy chess, meadow brome)

Pl. 139 e, f; Map 556

Plants annual, forming tufts. Flowering stems 30–120 cm long, erect or ascending, mostly glabrous. Leaves 4–6(–10) per stem. Leaf sheaths loosely overlapping toward the base of the stem, soft‑hairy (the upper ones often sparsely so), the tip strongly concave (V‑shaped), lacking a well‑defined ring of hairs on the outer surface and without auricles. Leaf blades 6–25 cm long, 1–8 mm wide, hairy, dull on the undersurface. Inflorescences open panicles with numerous spikelets, the branches spreading (especially the lowermost ones) or somewhat ascending at maturity, the stalks of the spikelets longer than the spikelets. Spikelets 10–22 mm long, slightly compressed laterally at maturity, with 4–12 florets. Lower glume 5–7 mm long, narrowly elliptic‑lanceolate, 3(5)‑nerved, glabrous to roughened or hairy. Upper glume 6–9 mm long, elliptic‑lanceolate, 5–9‑nerved, glabrous to roughened or hairy. Lemmas (7–)8–10 mm long, elliptic to oblanceolate, the distance (in lemmas toward the middle of the spikelet) from the midnerve to margin 1.5–2.5 mm at the widest point, rounded on the back, the margins not or only slightly inrolled at maturity, with an inconspicuous, narrow, whitened band, lightly 7(9)‑nerved, glabrous to roughened or hairy, the apical teeth 1–2 mm long, the awn (1.5–)5–12 mm long, rarely absent, straight or nearly so. Paleas slightly shorter than the lemmas. Anthers 0.7–1.7 mm long. Fruits 6–7 mm long, circular in cross‑section to somewhat flattened or slightly V‑shaped, the longitudinal groove narrow and shallow. 2n=14, 28, 56. Late May–July.

Introduced, scattered nearly throughout Missouri (native of Europe and Asia, widely naturalized in the U.S. and Canada). Roadsides, railroads, pastures, and open, disturbed areas.

The status of B. commutatus in North America has been controversial. Steyermark (1963) and several other authors reduced this to a synonym of the closely related B. racemosus, whereas most authors studying the plants in the Old World have regarded them as separate species. The present treatment follows those of Gereau (1987), Gleason and Cronquist (1991), and Pavlick (1995) in accepting these as distinct species. Depauperate or juvenile plants of this species also are very difficult to separate from B. japonicus or B. squarrosus. In addition to the characters in the key to species, B. commutatus differs from B. racemosus in having the florets attached mostly 1.5–2.0 mm (vs. 1.0–1.5 mm) apart on the rachilla.

 


 

 
 
© 2024 Missouri Botanical Garden - 4344 Shaw Boulevard - Saint Louis, Missouri 63110