Plants annual. Culms (2)6-16 cm. Ligules 0.5-1.5 mm, of hairs; blades 4-6 cm long, 0.5-2 mm wide, abaxial surfaces glabrous or sparsely pubescent, adaxial surfaces sparsely to densely pubescent. Panicles (1)2-3.5 cm. Spikelets 5-7 mm. Lower glumes 4.2-6.2 mm, equaling or exceeding the distal florets; upper glumes 4-6 mm; lemmas 1.8-2.6 mm, with dense, spreading pubescence between the veins, lobes longer than wide, acute to acuminate; paleas 1.5-2.2 mm, shorter than the lemmas; anthers 0.2-0.5 mm. Caryopses 0.5-0.8 mm. 2n = 12.
Schismus arabicus is native to southwestern Asia, but it is now established in the southwestern United States, growing in open and disturbed sites.
Common Name: Arabian schismus
Duration: Annual
Nativity: Non-Native
Lifeform: Graminoid
General: Low tufted annual grass, 10-20 cm tall; stems glabrous, erect to spreading or semi-prostrate.
Vegetative: Leaves mostly basal; blades 4-6 cm long, soft, bright green, narrow; sheath with membranous border above, often broad and truncate at apex; ligule a ring of short and long hairs, 0.5-1.5 mm long.
Inflorescence: Compact panicle, many flowered, 1-6 cm long; spikelets 5-7 mm long, 5-7 flowered; glumes 4-6 mm long, often tinged with purple, with hyaline margins; lemmas 2 mm long, the margin and back hairy, apex shallowly to deeply notched, forming a pair of acute lobes that are longer than wide; palea shorter than lemma, usually not reaching notch; caryopsis shiny golden brown.
Ecology: Found on dry open ground, often in disturbed soil, below 4,000 ft (1219 m); flowers January-May.
Distribution: Native to sw Asia, introduced throughout the world; in the US it is found in CA, s NV, s UT, AZ, s NM, sw TX; south to c MEX.
Notes: A small, low-growing, introduced, bunchgrass annual distinguished by its habit of often hugging the ground, spikelets of multiple florets, the florets with lemmas possessing long, soft hairs, a rounded apex with two acute lobes and semi-clear margins and tips. Distinguished from S. barbatus by its glumes which are the same length or longer than the lemmas; lemma lobes longer than they are wide; and paleas shorter than the lemmas. S. barbatus has glumes shorter than the last floret; lemma lobes wider than they are long; and paleas as long as the lemmas. The two species are thought to intergrade.
Ethnobotany: Unknown
Etymology: Schismus is from Greek schismos, cleaving, referring to split lemma, arabicus refers to being Arabian in origin.
Synonyms: None
Editor: SBuckley 2010, FSCoburn 2015, AHazelton 2015