306 RHINANTHACEAE. 



5. PENTSTEMON Soland. BEARD-TONGUE. 



Corolla blue, purple, white or yellowish, more or less funnelform or salverform. 

 Anthers bearded. I. GLABRI. 



Anther glabrous or merely hirtello-ciliate along the line of dehiscence. 

 Plant not suffruticose at the base. 

 Leaves not linear-filiform. 



Corolla decidedly funnelform, i. e,, throat much wider than the tube. 

 Sterile stamen glabrous ; plant tall, perfectly glabrous. 



I. GLABRI. 

 Sterile stamen bearded. 



Plant perfectly glabrous, or slightly puberulent above. 



Corolla strongly ventricose-gibbous ; tube proper very short. 

 Corolla over 3 cm. long ; stem-leaves clasping ; plant tall. 



II. GRANDIFLORI. 

 Corolla about 2 cm. long ; leaves linear or oblanceolate, not 



clasping ; plant low. III. HALLIANI. 



Corolla not ventricose-gibbous ; tube gradually dilated into a 



funnelform throat. IV. ACUMINATI. 



Plant glandular at least on the inflorescence. 



Stem glabrous below. V. GLAUCI. 



Stem glandular or puberulent. VI. CRISTATI. 



Corolla-tube almost cylindrical or slightly widening upwards ; corolla 



less than 2 cm. long. 

 Stems several from a branching rootstock, low and weak. 



VII. HARBOURIANI. 

 Stems solitary or a few from a taproot or short caudex. 



VIII. CONFERTI. 

 Leaves linear-filiform. 



Corolla-limb not strongly oblique ; sterile stamen bearded. 



IX. LARICIFOLII. 

 Corolla-limb strongly oblique ; sterile stamen glabrous. 



X. AMBIGUI. 



Plant suffruticose at the base. XL CAESPITOSI. 



Corolla red, almost tubular. 



Anthers opening for nearly their whole length. XII. BARBATI. 



Anthers opening only on their proximal part. XIII. BRIDGESIANI. 



I. GLABRI. 



Anthers bearded with long villous hairs. 

 Leaves and stem glabrous. 



Calyx-lobes acute or obtuse. i. P. strictus. 



Calyx-lobes long-acuminate. 2. P. strictiformis. 



Leaves and lower part of the stem densely and minutely puberulent. 



3. P. comarrhenus. 



Anthers glabrous or sparingly short-hirsute. 

 Anthers sparingly bearded. 



Stem-leaves all narrowly lanceolate. 



Calyx-lobes with narrow scarious margins, not auricled. 



Corolla about 1.5 cm. long; plant puberulent. 4. P. Fremontii. 



Corolla about 2 cm. long ; plant glabrous. 5. P. utahensis. 



Calyx-lobes with very broad scarious margins, forming erose auricles. 

 Stem and leaves glabrous. 6. P. oreophilus. 



Stem and leaves more or less puberulent. 7. P. alpinus. 



Upper stem-leaves broadly ovate or cordate. 8. P. Brandegei. 



Anthers and sterile filaments glabrous. 9. P. unilateralis. 



II. GRANDIFLORI. 

 One species. 10. P. grandiflorus. 



III. HALLIANI. 

 One species. n. P. Hallii. 



