210 SCROPHULARIACEAE 



Corolla purple. 



Calyx 2-3 mm. long; lobes rounded-ovate, acute, denticulate: leaves thin, the 



upper acuminate. 48. P. Watsonii. 



Calyx 5-6 mm. long: lobes ovate, abruptly acuminate or obtuse: leaves Arm. 

 not acuminate. 

 Corolla more than 1 cm. long: upper stem-leaves broadly lanceolate, often 

 rounded at the base; plants 3 dm. high or more." 

 Calyx-lobes ovate, acuminate. 49. P. Rydbergii. 



Calyx-lobes broadly obovate, obtuse or abruptly short-aciiminate. 



50. P. laxus. 

 Corolla less than 1 cm. long; limb small: upper stem-leaves linear-lanceo- 

 late; plant seldom more than 3 dm. high. 51. P. procerus. 

 Calyx and Inflorescence more or less glandular. 

 Leaves more or less denticulate. 



Upper stem-leaves broad, ovate-cordate, acuminate, clasping. 



Stem pubescent; calyx-lobes not scarious. 52. P. ovatus. 



Stem glabrous or sparingly puberulent up to the inflorescence; calyx-lobes 

 margined. 

 Leaves firm; inflorescence rather dense; calyx-lobes narrowly scarious- 



margined. 53. P. pine'torum. 



Leaves thin; inflorescence open; calyx -lobes not scarious- margined. 



54. C. leptophyllus. 

 Upper stem-leaves lanceolate or linear. 



Calyx-lobes elongate-lanceolate, not scarious; flowers ascending; stem- 

 leaves linear-lanceolate or linear. 62. P. gracilis. 

 Calyx-lobes ovate-lanceolate, scarious-margined below and usuaOy toothed : 

 stem-leaves oblong-lanceolate or lanceolate. 

 Tall, 3-5 dm. high; calyx-lobes acute. 55. P. Wilcoxii. 

 Low, less than 3 dm. high; calyx-lobes abruptly acuminate. 



60. P. rirens. 

 Leaves entire or essentially so. 



Plant depressed, decumbent; stems less than 2 dm. high; basal leaves usually 

 less than 3 cm. long, with rhombic-ovate or roimded-spatulate blades. 

 Corolla about 1.5 cm. long; stem-leaves more or less denticulate. 



5G. P. albertinus. 

 Corolla 1 cm. long or less; stem-leaves entire. 57. P. brcvifoUus. 



Plant not depressed, 2-7 dm. liigh; basal leaves more than 3 cm. long, with 

 oblanceolate blades: corolla 1.5 cm. long or more. 

 Calyx-lol)es ovate, broadly scarious-margined. 



Corolla sulphur-yellow. 58. P. allenuatus. 



Corolla pm-phsh. 



Stem-leaves ample, lanceolate or oblong. 

 Stem and leaves glabrous or nearly so. 



Leaves thick, darkening in drj-ing; stem-leaves always entire; 

 inflorescence interrupted, congested. 



59. P. pseudoprocerus. 

 Leaves tliin, not darkening in drying; stem-leaves usually den 

 ticulate; inflorescence not congested, a more or less contin- 

 uous panicle. 60. P. virens. 

 Stem and leaves decidedly puberulent. 68. P. humilis. 

 Stem-leaves Unear or linear-lanceolate, reduced; basal leaves numer- 

 ous, oblanceolate to almost linear. 61. P. aridus. 

 Calyx-lobes narrowly lanceolate, slightly scarious-margined. 



Leaves thick and darkening in drying; inflorescence congested and 

 interrupted; corolla dark blue-purple. 

 Plant 2-3 dm. liigh; upper stem-leaves linear-lanceolate or oblong. 



62. P. pseudohumilis. 

 Plant 5-7 dm. liigh; upper stem-leaves ovate-lanceolate, less than 

 half as long as the internodes. 50. P. laxus. 



Leaves tliin, light green, not darkening in drj-ing; inflorescence a con- 

 tinuous panicle: corolla white, light blue, or pink; leaves linear 

 or Itnear-lanceolate. 

 Stem glabrous or nearly so. 



Inflorescence narrow; pedicels shoit; stem-leaves linear-lanceo- 

 late. 63. P. gracilis. 

 Inflorescence open; pedicels long; stem-leaves narrowly linear. 



64. P. oliganthus. 

 Stem densely puberulent. 



Basal leaf-blades linear-oblanceolate. 



Throat of the corolla fmmelform, glandular-puberulent ,with- 

 in; limb ample; lower Up almost equalling the upper; sterile 

 stamen bearded at the end. 65. P. pubcrulenlus. 



Throat of the corolla almost cyUndric; limbsmall; lower lip 

 shorter than the upper, pubescent ^vitllin; sterile fila- 

 ment bearded at least half its length 

 Stem-leaves narrowly linear; calyx-lobes not scarious- 

 margined. 66. P. oreganus. 

 Stem-leaves narrowly lanceolate: calyx-lobes usually 

 with narrow scarioiLS margins. 67. P. rndicosus. 

 Basal leaf-blades oval or ovate. 68. P. humilis. 



XIII. Laricifolii. 

 Calyx-lobes distinctly scarious-margined; lower lip of the corolla slightly hairy within 

 or glabrous. 69. P. eiilifolius. 



