RHINANTHACEAE. 307 



IV. ACUMINATI. 



Inflorescence interrupted; bracts except the lowermost shorter than the flowers; 

 basal leaves spatulate or oblanceolate. 

 Bracts ovate to almost orbicular. 12. P. cyathophorus. 



Bracts lanceolate to linear-lanceolate. 



Calyx-lobes broadly obovate, scarious, erose, abruptly contracted into a 



very short acumination. 13. P. Watsonii. 



Calyx-lobes ovate or lanceolate, acute or gradually acuminate. 



Calyx-lobes lanceolate; plant 3-4 dm. high. 14. P. secundiHorus. 



Calyx-lobes ovate; plant 2 dm. high or less. 15. P. Fendleri. 



Inflorescence dense ; bracts large, long-acuminate, most of them exceeding the 

 flowers ; basal leaves linear or nearly so, narrower than the stem-leaves. 



16. P. angnstifoUus. 

 V. Glauci. 

 One species. 17. P. glaucus. 



VI. Cristati. 



Corolla-tube decidedly gibbous-ventricose ; sterile stamen densely yellow-villous ; 

 corolla purplish. 

 Basal leaf-blades obovate or spatulate or ovate, broader than the cauline leaves ; 



corolla about 1.5 cm. long. 18. P. Moffattii. 



Basal leaf-blades linear to linear-oblanceolate, usually narrower than the upper 

 cauline leaves; corolla 2-3 cm. long. 19. P. Jamesii. 



Corolla-tube funnelform, scarcely gibbous ; sterile stamen sparingly yellow-villous ; 

 corolla white. 20. P. albidtis. 



VII. Harbouriani. 

 One species. 21. P. Harbourii. 



VIII. CONFERTI. 



Leaves more or less dentate. 



Calyx-lobes elongated-lanceolate, not scarious ; flowers ascending ; stem-leaves 



linear-lanceolate or linear. 22. P. gracilis. 



Calyx-lobes ovate-lanceolate, scarious-margined below and usually toothed ; 

 stem-leaves oblong-lanceolate or lanceolate. 23. P. humilis. 



Leaves entire. 



Calyx glabrous or puberulent, but not at all glandular ; its lobes with very 

 broad, erose, scarious margins and abrupt acumination. 

 Corolla over i cm. long ; upper stem-leaves broadly lanceolate, often rounded 



at the base ; plant 3 dm. high or more. 24. P. Rydbergii. 



Corolla less than i cm. long ; upper stem-leaves linear-lanceolate ; plant 

 seldom over 3 dm. high. 25. P. procerus. 



Calyx and inflorescence more or less glandular. 



Plant glabrous or nearly so. 22. P. gracilis. 



Plant decidedly puberulent. 26. P. radicostis. 



IX. Laricifolii. 

 One species. 27. P. laricifolius. 



X. Ambigui. 

 One species. 28. P. ambigiius. 



XI. Caespitosi. 



Leaf-blades obovate, spatulate or broadly oblanceolate. 



Leaves green and glabrous or slightly puberulent ; calyx-lobes oblong-lanceolate. 



29. P. suifrutescens. 

 Leaves densely grayish or whitish puberulent ; calyx-lobes lanceolate. 



30. P. caespitosus. 

 Leaf-blades narrowly oblanceolate to linear or filiform. 



Calyx-lobes scarcely scarious-margined, entire ; inflorescence few-flowered ; 

 floral leaves like the rest. 



Leaves green and glabrate. 31. P. xylns. 



Leaves densely canescent-puberulent. z^- P- teucrioides. 



Calyx-lobes scarious-margined, dentate or erose ; inflorescence many-flowered, 



racemiform ; floral leaves reduced. 22- P- linarioides. 



