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Grasses of the Eloise Butler Wildflower Garden

The oldest public wildflower garden in the United States

Earlyleaf Brome

Common Name
Earlyleaf Brome (Flanged Brome)

 

Scientific Name
Bromus latiglumis (Shear) Hitchc.

 

Plant Family
Poaceae (Grasses)

Garden Location
Open Woodland

 

Prime Season
June, July, August

 

Grass structure and definitions - PDF from Oregon State University

Ligule Types, Shapes & Margins (pdf)

 

Earlyleaf or Flanged Brome is a perennial grass with stems that have 9 to 20 nodes and the nodes are usually concealed by a leaf sheath. Stems (culms) are erect and can be 30 to 60 inches tall and are usually not hairy.

Leaves: Leaf blades are 8 to 12 inches long and up to 5/8 inch wide.

Sheath throats and collars dense with hair; sheath surface can have hair or be smooth. Most lower blades have auricles (sometimes called 'flanges'). Ligules are very short, truncate, with fine surface and edge hair.

The inflorescence is a panicle, up to 8 inches long, of open shape and frequently nodding.

Flowers & spikelets: Spikelets are 15 to 30 mm long, somewhat elliptic in shape with 4 to 9 florets. Both lower and upper glumes are veined (1 vein usually on the lower and 3 on the upper), the upper glume longer (6-9 mm). Lemmas are 8 to 14 mm long, also mostly elliptic in shape, rounded over the midvein and margins with long hair. Florets have 2 anthers and awns that are straight, 3 to 4.5 mm long.

 

Habitat: Earlyleaf Brome grows in partial shade to open woodlands where there is adequate moisture; along stream banks and alluvial slopes. Unlike Smooth Brome it does not have rhizomes. It does not grow in warm, dry or humid areas - temperate only.

Names: The genus Bromus, is derived from the Greek bromos, referring to oats, as the flowering heads of this genus resemble oats somewhat. The species, latiglumis, is derived from two words - the Latin latus, (lati when plural) meaning wide, and glumis referring to the glumes - together 'wide glumes', although the leaf sheath area is a better place to look for indentification. The author names for the plant classification are: ‘Shear’ refers to Cornelius Lott Shear (1865-1956), American mycologist and plant pathologist and founder of the American Phytopathological Society which is devoted to the study of plant diseases. His work was updated by ‘Hitchc.’ who was Albert Spear Hitchcock (1865-1935) American botanist and agrostologist (one who studies grasses). He worked for USDA, authored more than 250 works, including the important Manual of the grasses of the United States.

Comparisons: An identifying characteristic is the two prominent flanges at the base of the leaf where it joins the stem. Seed production occurs in panicles that branch from the upper flower head portion of the stem. There are three species in the Garden. See bottom of page for an ID key.

See bottom of page for notes on the Garden's planting history, distribution in Minnesota and North America, lore and other references.

leaf sheathdrawing

Above: Leaf sheath, auricle and collar. Photo ©Anna Gardner, University of Iowa. Drawing from USDA-NRCS PLANTS Database / USDA NRCS. Wetland flora: Field office illustrated guide to plant species.

Below: Upper portion of the plant, ©Robert W. Freckmann, Freckmann Herbarium, University of Wisconsin. Drawing by Agnes Chase from Norman C. Fassett's Grasses of Wisconsin

Earlyleaf BromeEarlyleaf Brome drawing

Below: Spikelets. Photos ©Anna Gardner, University of Iowa.

spike floret

BELOW: A comparison of the three species of Bromis at Eloise Butler.

Species B. inermis B. latiglumis B. pubescens
Smooth Brome Earlyleaf Brome Hairy Woodland Brome
Rhizomes present Yes No No
Stems (all are erect)
Height 1.5 to 4 feet 3 to 5 feet 2 to 4 feet
# of stem nodes 3-5 9-20 5-7
Stems hairy? usually not usually not usually
Leaf sheaths hairy? usually not can be, throats and collars densely hairy usually, backward bent
Ligules to 3mm. smooth 0.8 to 1.4mm hairy 0.5 to 2mm smooth
Leaf Blades
Length 4 - 14", flat 8 - 12", flat 5 - 13", flat
Width to 15mm (5/8") to 15mm (5/8") to 15mm (5/8")
Hair on blades usually not usually not can be with or without
Special feature 2 prominent flanges on collar
Panicles 10 -20 cm long (4 to 8") 10 - 22 cm long 10 - 25 cm long
open open open
erect nodding usually nodding
Panicle branches ascending or spreading ascending or spreading spreading, sometimes ascending, usually drooping
Spikelets 20-40 mm long, sometimes purplish, with 8-10 florets 15-30mm long with 4-9 florets 15-30mm long with 5-10 florets.
Glumes with or without hair without either way usually soft fine hair
Lemmas usually without hair longhair on margins margins usually hairy
Awns present absent or to 3mm 3 - 4.5mm, straight 4-7mm, straight.

Notes:

Earlyleaf Brome or Flanged Brome is a native perennial that grows from the Great Plains eastward and north of the old Mason-Dixon line. Also found in all the lower Canadian Provinces except Labrador and Newfoundland. In Minnesota it is generally found south and west of a diagonal line from Pine county northwest to Kittson county, with a number of absences, principally in the SW Counties. There are 52 species of Bromus in the United States, 28 native and 24 introduced. Eight of those species are in Minnesota - 4 native and 4 introduced. Worldwide the estimate is 100-400 species.

References and site links

References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.

graphicIdentification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.



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