SCROPHULARIACEAE. 



[Vol. III. 



4. Pentstemon albidus Nutt. White- 

 flowered Beard-tongue. (Fig. 3250. ) 



PenlsUmon albiihts Nutt. Gen. 2: s.V 181S. 



Stem puberulent below, densely glandular- pubes- 

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

 lower leaves spatiilate or oblong, obtusish, mostly 

 entire, the upper lanceolate or obloDfj, sessile, den- 

 ticulate, acute or acuminate, ^]z'-2]!.' long. 3"-6" 

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

 interrupted; calyx-segments lanceolate, acuminate, 

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

 white or nearly so, S"-io" long, fiinnelform, the 

 tube gradually dilated upward, the limb nearly 

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

 ment slightly bearded with short hairs. 



On drj' plains, South Dakota to Colorado, Nebraska 

 and Texas, June-Aug. 



5. Pentstemon Digitalis (Sweet) Nutt. 

 Foxglove Beard-tongue. (Fig. 3251.) 



Chelotie Digitalis Sweet, Brit. Fl. Gard. 2: pi. no. 



1S25-27. 

 Pcnlslenion Digitalis Nutt. Trans. Am. Phil, Soc. 



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

 Pcntstciiiott laevtgatus var. Digitalis .\. Gray, Syn. 



Fl. 2: Part i, 268. 1S7S. 



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'-"' 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' long, 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 .\rkansas. 

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



6. Pentstemon Pentstemon (L.) Britt 



Smooth Beard-tongue. (Fig. 3252.) 



Clieloiic Pentstemon L. Sp. PI. Ed. 2, 850. 176,5. 

 Pentstemon laez'igatiis Soland. in .Ait. Hort. 



Kew. 2: 300. 1789. 

 Pentstemon Pentstemon Britten, 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'-s' 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, S"-io" long, the tube 

 gradually enlarged above, the throat wide 

 open, scarcely or not at all bearded; sterile 

 filament thinly bearded for about one-half its 

 length, or more densely bearded above. 



In woods and thickets. Pennsylvania to Flor- 

 ida, west to Kentuckj- and Louisiana. Occa- 

 sionally escaped from cultivation further east. 

 May-July. 



