SCROPHULARIACEAE (FIG WORT FAMILY) 443 



proper tube of nearly twice the length of the calyx, abruptly dilated into the 

 broadly campanulate throat of about 8 mm. in height and width; this nearly 

 equaled by the widely spreading lips; the lobes round-oval: sterile filament 

 glabrous or minutely bearded at the dilated tip. P. secundifiorus. In the 

 mountains of Colorado and Wyoming. 



15. Pentstemon Haydenii Wats. Bot. Gaz. 16: 311. 1891. More or less 

 glaucous; stem decumbent, leafy, 3-6 dm. high: leaves linear or elongated- 

 lanceolate, entire, sessile and slightly clasping, acute, acuminate, or the lowest 

 obtusish, 5-13 cm. long, 2-10 mm. wide: thyrsus narrow, dense; bracts ovate 

 or ovate-lanceolate, large, cordate-clasping, acute or acuminate: calyx- 

 segments lanceolate, striate-nerved, acuminate, 6-10 mm. long: corolla blue, 

 the tube broadly dilated above the calyx, the limb nearly equally 5-lobed: 

 capsule acute, twice as long as the calyx. In Kansas and Nebraska and the 

 eastern part of our range. 



16. Pentstemon Hallii Gray, Proc. Am. Acad. 6: 71. 1866. Stems 1-2 dm. 

 high: leaves thickish, linear and linear-spatulate, or the lowest rather broader, 

 obtuse: thyrsus short and spiciform, 5-15-flowered, obscurely viscid: sepals 

 broadly ovate and with widely scarious, erose margins: corolla 15-20 mm. long, 

 broadly campanulate-inflated from a thickish and inconspicuous proper tube 

 which is shorter than the calyx; bilabiate limb rather short: sterile filament 

 short-bearded from the apex downward. In the Colorado mountains at high 

 elevations. 



17. Pentstemon angustifolius Pursh, Fl. Am. Sept. 738. 1814. Glaucous; 

 stem slender, leafy, 1.5-2 dm. high: leaves linear or linear-lanceolate, entire, 

 the lower narrowed into petioles, obtusish, the upper sessile acute, 3-6.5 cm. 

 long, 3-4 mm. wide: thyrsus narrow, spike-like, mostly. dense; bracts lanceo- 

 late, acuminate; pedicels very short: calyx-segments linear-lanceolate, acu- 

 minate, 4-6 mm. long: corolla blue or nearly white, the tube gradually en- 

 larged, the limb somewhat 2-lipped: sterile filament bearded at the summit. 

 P. caeruieus. In dry soil; from the base of the mountains to Nebraska and 

 Dakota. 



18. Pentstemon laricifolius H. & A. Bot. Beech. 376. 1841. Glabrous; 

 stems tufted, 5-18 cm. high; lignescent caudex not rising above the soil: 

 leaves slender, when dry filiform and with the margins revolute, the larger 

 1-2 mm. wide, 2-4 cm. long, much crowded in subradical tufts and scattered 

 on the slender flowering stems: flowers few, loosely racemose, slender-pediceled: 

 sepals ovate-lanceolate: corolla tubular-funnelform, 12-18 mm. long, purple, 

 the small limb obscurely bilabiate: sterile filament bearded on the upper side. 

 (P. exilifolius desertus A. Nels. 1. c. 28: 231; P. aridus Rydb. Mem. N. Y. 

 Bot. Gard. 1: 348. 1900 much resembles this but has a glandular-pubescent 

 inflorescence with "blue " flowers. It occurs in the arid plains of Montana.)--- 

 P. laricifolius was described from Oregon plants, but aside from the greater 

 size in every way ours from Wyoming and Colorado do not seem to differ 

 essentially. 



19. Pentstemon exilifolius A. Nels. 1. c. 28: 230. Stems several to nu- 

 merous, from a tufted branched caudex, glabrous, as are also the leaves and 

 inflorescence, 1 (rarely 2) dm. high: leaves very numerous, crowded on the 

 crowns, narrowly linear, channeled or involute, subulate-pointed, 15-25 mm. 

 long; stem leaves simitar, passing into the smaller bracts: thyrsus narrow, 

 crowded, few to many-flowered; pedicels slender: sepals lanceolate and long- 

 acuminate, erose, scarious-margined : corolla white, tubular-funnelform, 

 12-15 mm. long, obscurely pubescent in the throat, scarcely bilabiate, the 

 nearly orbicular lobes widely spreading, 6-7 mm. long: anthers glabrous, the 

 sterile filament scarcely dilated, very stiffly and densely short-pubescent. 

 Dry stony plains and hills; Wyoming and northern Colorado. 



20. Pentstemon ambiguus Torr. 1. c. 2: 228. 1828. Glabrous, 2-5 dm. 

 high, diffuse and often much branched: leaves filiform, or the lowest linear 

 and the floral slender-subulate: inflorescence loosely paniculate: sepals ovate, 

 acuminate: corolla rose-color and flesh-color turning to white, narrow and 

 somewhat curved, about 12 mm. long, the scarcely expanded limb oblique but 



