c. 



rosette leaves petiolate, entire, (1) 1.5-2.5 (3) 

 cm ((0.4) 0.6-1.0 (1.2) in.) long, blade 

 elliptical to broadly ovate or obovate, usually 

 narrowed abruptly, 3-6 (7) mm (0.12-0.24 (0.28) 

 in.) wide, 4-7 mm (0.16-0.28 in.) long, obtuse; 

 cauline leaves 3-6, spatulate, cuneate at base, 3- 

 7 mm (0.12-0.28 in.) long; inflorescences 3-5 

 flowered, scarcely elongating in fruit; sepals 

 yellowish, oblong, densely pubescent, 4-5 mm 

 (0.16-0.20 in.) long, 1.5-2 mm (0.06-0.08 in.) 

 wide, outer pair slightly saccate, inner pair non- 

 saccate; petals yellow, spatulate, retuse or 

 rarely with a deeper sinus at apex, narrowed 

 gradually from blade to claw, 7-8.5 mm (0.28-0.33 

 in.) long, 3-3.5 mm (0.12-0.14 in.) wide; stamens 

 strongly tetradynamous; filaments of paired 

 stamens ca. 4 mm (0.16 in.) long, anthers ca. 1 mm 

 (0.04 in.) long; pedicels straight to slightly 

 curved, nearly paralleling rachis, 3-4 mm (0.12- 

 0.16 in.) high, 4-5 mm (0.16-0.20 in.) wide, 

 valves densely pubescent on exterior with 

 trichomes that have ascending to erect rays, 

 sparsely pubescent on interior; replum oval to 

 broadly oblong, acute at apex, 2.5-3.5 mm (0.10- 

 0.14 in.) long; septum usually folded; styles 2-3 

 mm (0.08-0.12 in.) long; ovules 2 in each locule; 

 seeds plump, wingless, slightly compressed, 

 orbicular to semiorbicular, ca. 2 mm (0.08 in.) in 

 diameter; cotyledons accumbent, orbicular or 

 nearly so (Rollins 1984). 



Local field characters: During field surveys in 

 1987, one other conspicuous member of the Mustard 

 family, Smelowskia calvcina (Alpine smelowskia) , 

 was observed growing with L. humilis . Smelowskia 

 is distinguished in having white petals, which are 

 sometimes purple-tinged, and pinnatifid or pinnate 

 (lobed or divided) leaves. These are in contrast 

 to the yellow petals and entire (smooth-margined) 

 leaves of L. humilis . Several other species in 

 the Mustard family have been reported from St. 

 Mary Peak, including Arabis spp. and Draba spp. 

 (Lackschewitz 1970) . Members of Arabis in Montana 

 have white to pink or purple petals and longer, 

 narrow fruits; Draba species often have strongly 

 flattened fruits which are flattened parallel to 

 the septum (internal fruit partition), rather than 

 being not, or only partially, flattened in 

 Lesguerella . 



