SCROPHULARIACEAE. 



VOL. III. 



5. Pentstemon albidus Nutt. White-flowered 

 Beard-tongue. Fig. 3759. 



Pentstemon albidus Nutt. Gen. 2: 53. 1818. 



Stems puberulent below, densely glandular-pubes- 

 cent above, rather stout, 6'-io' high. Basal and lower 

 leaves spatulate or oblong, obtusish, mostly entire, 

 the upper lanceolate or oblong, sessile, denticulate, 

 acute or acuminate, ii'-2i' long, 3"-6" wide; thyrsus 

 narrow, raceme-like, leafy-bracted, interrupted; ca- 

 lyx-segments lanceolate, acuminate, viscid, one-half 

 as long as the corolla-tube; corolla white or nearly 

 so, 8"-io" long, funnelform, the tube gradually di- 

 lated upward, the limb nearly equally 5-lobed, the 

 lobes spreading; sterile filament slightly bearded with 

 short hairs. 



On plains, Minnesota and South Dakota to Assini- 

 boia, Colorado, Nebraska and Texas. June-Aug. 



6. Pentstemon Pentstemon (L.) Brit- 

 ton. Smooth Beard-tongue. 

 Fig. 3760. 



Chelone Pentstemon L. Sp. PI. Ed. 2, 850. 1763. 

 Pentstemon laevigatus Soland. in Ait. Hort. Kew. 



2 : 300. 1789. 

 P. Pentstemon Britt. Mem. Torr. Club 5 : 291. 1894. 



Glabrous, except the somewhat glandular- 

 pubescent inflorescence ; stem slender, 2-3 

 high. Basal and lower leaves oblong or oval, 

 obtuse, 3'-6' long, narrowed into margined 

 petioles, denticulate; upper leaves sessile or 

 slightly clasping, acute, oblong, or lanceolate, 

 denticulate ; thyrsus open, usually many-flow- 

 ered ; flowers nearly sessile ; calyx-segments 

 lanceolate, acute, short ; corolla purple or pur- 

 plish, 8"-io" long, the tube gradually enlarged 

 above, the throat wide open, scarcely or not at 

 all bearded, the lobes spreading; sterile fila- 

 ment thinly bearded for about one-half its 

 length, or more densely bearded above. 



Occasionally escaped 



Woods and thickets, Pennsylvania to Florida, Kentucky and Louisiana, 

 from cultivation further north and east. May-July. 



7. Pentstemon Digitalis (Sweet) Nutt. 

 Foxglove Beard-tongue. Fig. 3761. 



Chelone Digitalis Sweet, Brit. Fl. Card. 2 : pi. 120. 



1825-27. 

 Pentstemon Digitalis Nutt. Trans. Am. Phil. Soc. 



(II.) 5: 181. 1833-37- 

 Pentstemon laevigatus var. Digitalis A. Gray, Syn. 



Fl. 2: Part i, 268. 1878. 



Glabrous, except the glandular-pubescent > in- 

 florescence; stem rather stout, 2-5 high. 

 Lower and basal leaves oblong or oval, obtuse 

 or acutish, entire or repand, 2,'-f long, nar- 

 rowed into margined petioles; upper leaves 

 ovate, lanceolate or ovate-lanceolate, sessile 

 and more or less cordate-clasping at the base, 

 acuminate, sharply denticulate ; thyrsus open, 

 many-flowered ; pedicels i"-z'\ long ; calyx- 

 segments lanceolate, corolla white, i'-ii' long, 

 the tube abruptly dilated, the limb moderately 

 2-lipped, the throat open; sterile filament 

 bearded above. 



In fields and thickets, Maine to New York, Illi- 

 nois, Kansas, Virginia and Arkansas. Doubtless 

 escaped from cultivation in its northeastern range. 

 May-July. 



