1. GENERAL NONTECHNICAL DESCRIPTION: Biennial or short-lived 

 perennial herb with a single branched or unbranched stem; 1-4 dm 

 high. It has a basal rosette of leaves, and sessile, clasping 

 stem leaves that are slightly serrated. The stems are pubescent 

 above. The white flowers are small but numerous. The fruits are 

 erect (Figure 4) . 



2. TECHNICAL DESCRIPTION: Biennial or perennial; stems usually 

 single from a simple caudex, branched above or below, erect or 

 ascending, 1-4 dm. high, hirsute below with a mixture of large 

 and small trichomes, pubescent above with small appressed 

 trichomes; basal leaves narrowly oblanceolate, sinuate-dentate, 

 petiolate, densely pubescent with dendritic trichomes, 2-6 cm. 

 long, 5-10 mm. wide; cauline leaves sessile, auricled, remote, 

 lanceolate, densely pubescent, 1.5-4 cm. long, 2-7 mm. wide; 

 infloresence fairly lax; anthers about 0.5 mm. long, broadly 

 oblong; nectar-glands weakly developed, continuous beneath all 

 stamens; sepals nonsaccate, hirsute with relatively large 

 trichomes, 2-3 mm. long, about 1 mm. wide; petals white, 

 spathulate with a slender claw, 3-4 mm. long, about 1.5 mm. wide; 

 pedicels divaricately ascending, slender, pubescent, 5-12 mm. 

 long; siliques erect, glabrous, nearly terete to slightly 

 flattened parallel to septum, 2-4 mm. long, about 1 mm. wide; 

 valves nerved from base to apex; styles about 0.5 mm. long; 

 stigma unexpanded or only slightly expanded; seed oblong, about 1 

 mm. long, biseriate; cotyledons incumbent (Rollins 1943) . 



3. LOCAL FIELD CHARACTERS: The only members of the Mustard Family 

 with which it might be confused are species of Arabis with 

 upright siliques, though they have flattened fruits, and species 

 of Sisymbrium , though they have dissected leaves. 



Misidentif ication of Arabis hirsuta for Halilmolobos virqata was 

 made for a Sheridan County specimen. The latter has ascending 

 siliques closely paralleling the stem as compared to diverging, 

 with small petals of 2-3 mm as compared to >4 mm, and round 

 - siliques with biseriate seeds as compared to flattened siliques 

 with uniseriate seeds (Fertig pers. commun.). 



D. GEOGRAPHICAL DISTRIBUTION 



1. RANGE: • Halimolobos virqata is distributed mainly along foothills 

 of the Rocky Mountains. Hitchcock and Cronquist (1973) 

 characterize its distribution as extending from Alberta and 

 Saskatchewan to Colorado and Utah, extending all the way north to 

 the Yukon. However, Scoggan (1978) refers all material outside 

 southern Alberta and southwestern Saskatchewan to Halimolobos 

 mollis . The Halimolobos virqata is ranked critically imperiled 

 (SI) in Alberta and Saskatchewan, and status unknown (SU) in 

 Colorado. It is known from twenty collections spanning over half 

 of Wyoming from a wide array of habitats, which provides basis 

 for lowering its global rank to at least G3 (Fertig pers. 

 commun. ) . 



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