SCROPHULARIACEAE. 



[Vol. III. 



4. Pentstemon albidus Nutt. White- 

 flowered Beard-tongue. (Fig. 3250.) 



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



Stem 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, den- 

 ticulate, acute or acuminate, i^ / -2^ / long, 3 // -6 // ' 

 wide; thyrsus narrow, raceme-like, leafy-bracted, 

 interrupted; calyx-segments lanceolate, acuminate,, 

 viscid, one-half as long as the corolla-tube; corolla 

 white or nearly so, 8 // -io // long, funnelform, the 

 tube gradually dilated upward, the limb nearly 

 equally 5-lobed, the lobes spreading; sterile fila- 

 ment slightly bearded with short hairs. 



On dry plains, South Dakota to Colorado, Nebraska 

 and Texas. June-Aug. 



5. Pentstemon Digitalis (Sweet) Nutt. 

 Foxglove Beard-tongue. (Fig. 3251.) 



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



1825-27. 

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



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



Pentstemon laevigatas var. Digitalis A. Gray, Syn. 



Fl. 2: Part 1, 268. 1878. 



Glabrous, except the glandular-pubescent in- 

 florescence; stem rather stout,2-5 high. Lower 

 and basal leaves oblong or oval, obtuse or acut- 

 ish, entire or repand, 2 / -7 / long, narrowed into 

 margined petioles; upper leaves ovate, lanceo- 

 late or ovate-lanceolate, sessile and more or less 

 cordate-clasping at the base, acuminate, sharply 

 denticulate; thyrsus open, many-flowered; pedi- 

 cels i // ~3 // long; calyx-segments lanceolate; 

 corolla white, i'-iX' lo ng, the tube abruptly 

 dilated, the limb moderately 2-lipped, the throat 

 open; sterile filament bearded above. 



In fields and thickets, Maine and New York to Illinois, south to Virginia and Arkansas. 

 Doubtless escaped from cultivation in its northeastern range. May-July. 



6. Pentstemon Pentstemon (L,.) Britt. Smooth Beard-tongue. (Fig. 3252.) 



Chelone Pentstemon L- Sp. PL Ed. 2, 850. 1763. 

 Pentstemon laevigatas Soland. in Ait. Hort. 



Kew. 2: 300. 1789. 

 Pentstemon Pentstemon Britton, 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 / -5 / long, narrowed into mar- 

 gined petioles, denticulate; upper leaves ses- 

 sile or slightly clasping, acute, oblong, or 

 lanceolate, denticulate; thyrsus open, usually 

 many-flowered; flowers nearly sessile; calyx- 

 segments lanceolate, acute, short; corolla 

 purple or purplish, 8 // -io // long, the tube 

 gradually enlarged above, the throat wide 

 open, scarcely or not at all bearded; sterile 

 filiment thinly bearded for about one-half its 

 length, or more densely bearded above. 



In woods and thickets, Pennsylvania to Flor- 

 ida, west to Kentucky and Louisiana. Occa- 

 sionally escaped from cultivation further east. 

 May-July. 



