Oniongrass

Oniongrass, courtesy of Dr. Chris Call, Utah State University

Photo Courtesy of Dr. Chris Call, Utah State University

Common Name(s):

Oniongrass

Scientific Name:

Melica bulbosa Geyer ex Porter & Coult.

Scientific Name Synonyms:

Bromelica bulbosa (Geyer ex Porter & Coult.) W.A. Weber
Melica bella Piper
Melica inflata (Boland.) Vasey

Symbol:

MEBU

Description:

Life Span: Perennial
Origin: Native
Season: Cool

 

Growth Characteristics: Oniongrass is an erect bunchgrass, often with rhizomes. It grow 1 to 2 ½ feet tall, usually growing in clumps

Seedhead: The seedhead is long and narrow (10–16 cm) with short, thick branches that are upward pointing and pressed close to the stem axis. The spikelets range from one to several per branch and overlap. The glumes are narrow, blunt and papery and are slightly shorter or equal to the first flower. The rough lemmas have stiff hairs or in some cases bumps, and are distinctly two-colored. The sterile upper flowers consist only of empty lemmas. There are no awns.

 

Leaves: The leaf sheaths are closed almost their full length and feel rough because they are covered in tiny, stiff hairs. The ligules are 3-4 mm long, membrane-like, open in the front and have ragged edges. In addition, there are no auricles and the callus is not bearded. The rough, flat leaves are somewhat inrolled and 2-4 mm wide.

Stems: The stems are slightly bent near the base which is noticeably bulbous under a covering of old leaf sheaths. The stem nodes are dark at maturity.

Ecological Adaptations:

This native bunchgrass is somewhat unique it its form, having a bulbous base, and in that it is widely distributed throughout the Utah mountains in the bottomlands, alluvial fans, benches, mountain slopes, valleys and ridgetops, on all exposures but primarily the north and east. It occurs in areas receiving 14 to 40 inches of annual precipitation.

 

Soils: Oniongrass grows best on deep well-developed loams and fine textured soils but also tolerates sands and clays that are moderately deep but even gravelly and stony soils. 

Associated Species: Slender wheatgrass, bearded wheatgrass, mountain brome, arrowleaf balsamroot, bigtooth maple, aspen, and snowberry.

Uses and Management:

Oniongrass is an excellent forage plant for all classes of domestic livestock, elk, and deer. A variety of small animals use both the seeds and the bulbs.

 

It is an attractive plant of interest for its structural characteristics. It is fair to good as a plant for controlling erosion along with other plants but not very effective as a soil binder in pure stands. 

Management can effectively maintain the productivity of this type of plant by limiting utilization to about one-half the current season’s forage yield and allowing an occasional rest from grazing during the critical period of growth.