33 Rydberg : Studies on the Rocky Mountain Flora 



upper leaves : pedicels very short, often sparingly strigulose : calyx 

 divided to near the base ; sepals oblong, obtuse, ciliate on the 

 margins, 2—3 mm. long, scarcely more than half as long as the 

 tube of the corolla : corolla dark blue, about 7 mm. long : tube 

 nearly equaling the throat and limb : stamens short, included in 

 the tube, filaments very short, not broader than the anthers. 



This species is nearest related to M. Tzveedyi, but differs in 

 the shorter, obtuse calyx-lobes, the broader and thinner leaves 

 and the stem which is not depressed or prostrate. It grows at an 

 altitude of 2000-3500 m. 



Colorado: Pikes Peak, 1900, Fred. Cieuients (type); Garden 

 of the Gods and Pikes Peak, 1894, Ernst A. Bessey ; Argentine 

 Pass, 1878, Marcus E. J'o>ics, jy. 



Mertensia membranacea sp. nov. 



A tall erect perennial with a rather thick tap-root. Stem gla- 

 brous or sparingly hirsute above, 6—8 dm. high : leaves all petioled, 

 or the upper sessile ; blades ovate, acute or more often short acu- 

 minate, 4— 8 cm. long, 1.5—4 cm. wide, very thin, hispid-stringulose 

 on both sides : flower-clusters terminal and in the axils of the upper 

 leaves, branched and many-flowered : pedicels 5—10 mm. long, his- 

 pidulous: calyx-lobes 2—3 mm. long, hispidulous, lanceolate, acute, 

 one-third or one-fourth as long as the tube of the corolla : corolla 

 about I cm. long ; the pale blue or almost white tube longer than 

 the dark blue limb and throat : limb about 4 mm. broad : stamens 

 much shorter than the limb ; filaments dilated and broader than 

 the anthers : nutlets strongly rugose and spotted. 



This species is related to M. paniculata. Mr. Bessey and my- 

 self collected it in 1897, but as the specimens were rather poor, 

 they were referred doubtfully to that species. As more and bet- 

 ter specimens have now been received, it has been possible to draw 

 a description. It differs from M. paniculata, in the thinner leaves 

 which almost always show an acumination, in the short calyx-lobes 

 which scarcely enlarge in fruit and the smaller and numerous 

 flowers. It grows in moist places at an altitude of 300—2000 m. 



Idaho : Priest River, 1900, D. T. MacDoiigal, j (type) ; Cedar 

 Mountain, 1892, Sandberg, MacDoiigal & Heller, ^20. 



Montana : Electric Peak, 1897, Rydberg & Bessey, ^864. 



Mentzelia ctenophora sp. nov. 



A diffuse cespitose scabrous perennial. Stems 2)-^ dm. long, 

 branched, in agfe straw-colored : lower leaves linear or linear-Ian- 



