Nelson : New Plants from Wyoming 269 



v Mimulus thermalis 



Annual, erect, simple stemmed, only a few cm. high (3-15), 

 dull green and more or less tinged with red, glabrate below, pu- 

 berulent upward, not viscid nor glandular : leaves 2-5 pairs, nearly 

 orbicular, obscurely dentate, closely sessile or the lower on very 

 short petioles, mostly obtuse, the uppermost abruptly short toothed, 

 3-5 -nerved from the base, all small (3-9 mm.), often floriferous to 

 the base : flowers In pairs in the axils, sometimes a single terminal 

 flower or with the pair immediately below appearing cymose ; the 

 lower pedicels (in large plants) elongated and with a pair of leaf- 

 like bracts above the middle, in small plants slender and not much 

 longer than the calyx : calyx narrowly campanulate, strongly cari- 

 nate-angled, somewhat oblique, in fruit 1 cm. long, its teeth short, 

 the upper about twice as long as the others : corolla about 1 5 mm. 

 long, funnelform, the tube nearly equaling the limb and but little 

 exceeding the calyx, yellow, bilabiate, short pubescent on the 

 lower lip : capsule shorter than the calyx, conspicuously stipitate ; 

 the seeds numerous, small, elliptic, the surface obscurely check- 

 ered by longitudinal and less distinct transverse lines. 



I am unable to find a close ally for this species but its charac- 



* 



ters would place it into the section in which M. nttdatns, M. nas- 

 sutus and M. microphyllus are conspicuous members. It was 

 secured in Yellowstone Park where it occurs more or less freely 

 on the formations in the vicinity of the hot springs and geysers. 

 The type is no. 6285, Upper Geyser Basin, Aug. 3, 1899. 



v Castilleja lauta 



Perennial, from a short, thickened, woody caudex : stems 

 several or sometimes numerous, simple, erect from a more or less 

 curved ascending base, from yellowish-green to purplish, from 

 smooth and shining to striate and granular-puberulent, 1-3 dm. 

 high : leaves very variable, 2—5 cm. long or the lower much 

 reduced, from linear-lanceolate, acuminate, entire to more broadly 

 lanceolate to obtusish : upwardly becoming broadened at apex 

 and toothed or cleft or with short lateral lobes, from glabrate- 

 puberulent below to lanate-ciliate above : inflorescence at first short 

 and dense, comparatively short even in fruit, gay or almost gaudy, 

 the purple bracts large, lanate-ciliate, dilated upward, entire or 

 3 -cleft, the middle lobe broadest, nearly equaling the flowers : 

 calyx equally cleft to about the middle, the two lobes again cleft to 

 about the middle into oblong-lanceolate lobes : corolla yellow and 

 more or less streaked with purple on the lower side, 18—22 mm. 

 long, galea about x / 2 as long as the tube, truncate and obscurely 



