SCROPHULAAIA CEAE. 825 



5. Pentstemon Digitalis (Sweet) Nutt. Foxglove Beard-tongue. (L F. f. 

 3251.) Glabrous except the glandular-pubescent inflorescence, 6-15 dm. hi^h. 

 Lower and basal leaves oblong or oval, entire or repand, 5-17 cm. long, narrowed 

 into margined petioles; upper leaves ovate, lanceolate or ovate-lanceolate, sessile 

 ami more or less cordate-clasping at the base, acuminate, sharply denticulate; 

 Kyrsus many-flowered; pedicels 2-6 mm. long; calyx-segments lanceolate; corolla 

 limb moderately 2 lipped, the throat open; sterile filament bearded above. In 

 fields and thickets, Me. to 111., Kans., Va. and Ark. Escaped from cultivation in 

 its northeastern range. May-July. 



6 Pentstemon Pentstemon (L.) Britton. Smooth Beard-tongue. (I. F. f. 

 3252.) Glabrous, except the glandular-pubescent inflorescence, 6-9 dm. high. 

 Basal and lower leaves oblong or oval, obtuse, 7-15 cm. long, narrowed into mar- 

 gined petioles, denticulate; upper leaves sessile or slightly clasping, acute, oblong 

 or lanceolate, denticulate; thyrsus usually many-flowered; flowers nearly sessile; 

 calvx-segments lanceolate, acute, short; corolla purple or purplish, the throat wide 

 open, scarcely or not at all bearded; sterile filament thinly bearded for about one- 

 half its length, or more densely above. In woods and thickets, Penn. to Fla., Ky. 

 and La. May-July. 



7. Pentstemon calycosus Small. Long-sepaled Beard-tongue. Gla- 

 brous except a few scattered hairs in the inflorescence and lines of puberulence on 

 the internodes, deep green. Leaves various, the basal spatulate, 5-15 cm. long, 

 entire or undulate, with winged petioles ; lower stem-leaves similar to the basal, 

 the upper lanceolate or ovate- lanceolate, acute or acuminate, finely repand or dis- 

 tinctly serrate, rounded at the base and clasping; calyx-segments with a lanceo- 

 late base and a slender tip, becoming I cm. long; corolla purple, 2.5-3 cm. long; 

 sterile filament sparingly bearded. On bluffs, Ky. to Mo. and Ala. May-June. 



8. Pentstemon gracilis Nutt. Slender Beard-tongue. (I. F. f. 3253.) 

 Glabrous or nearly so up to the glandular-pubescent inflorescence; stem slender, 

 1.5-4.5 dm. high. Basal and lower leaves linear-oblong or spatulate, denticulate. 

 or entire, 2-8 cm. long, narrowed into margined petioles; upper leaves sessile 

 linear-lanceolate or the uppermost lanceolate, acuminate, denticulate; thyrsur 

 open, several-many-flowered; pedicels 4-8 mm. long; calyx-segments lanceolate, 

 acute or acuminate; corolla purple, 1.8-2.5 cm. long, its tube gradually enlarged 

 above, its throat wide open; sterile filament bearded for about one-half its length. 

 On moist prairies, Manitoba to Minn., Miss., the N.W. Terr, and Colo. May-July. 



9. Pentstemon tubiflorus Nutt. Funnelform Beard-tongue. (I. F. f. 

 3254.) Glabrous, except the viscid-pubescent calyx and pedicels; stem 6-10 dm. 

 high, leafless above. Leaves oblong, ovate, or lanceolate, 2-10 cm. long, the basal 

 narrowed into broad margined petioles, the upper sessile or clasping, entire or 

 merely undulate; thyrsus narrow, interrupted, the clusters several-flowered; pedi- 

 cels 2-6 mm. long; calyx-segments ovate, acuminate, short, striate-nerved ; corolla 

 nearly funnelform, white or purplish, less than 2.5 cm. long, nearly as broad when 

 expanded, its tube gradually enlarged, the limb nearly equally five-lobed; sterile 

 filament short bearded above; capsule acute, about twice as long as the calyx. In 

 moist soil. Mo. and Kans. to Ark. May-July. 



10. Pentstemon Cobaea Nutt. Cobaea Beard-tongue. (I. F. f. 3255.) 

 Densely and finely pubescent below, glandular-pubescent above, 3-6 dm. high. 

 Leaves oblong to ovate, firm. 7- 13 cm. long, dentate, the lower mostly glabrous 

 and narrowed into margined petioles, the upper sessile or cordate-clasping, usually 

 pubescent; thyrsus short; calyx-segments lanceolate, acuminate, I-I.5 cm. long; 

 corolla purple, puberulent without, its tube narrow up to the top of the calyx, then 

 abruptly dilated, the lobes short, rounded; sterile filament sparingly bearded; 

 capsule ovoid, acute, pubescent, reticulate-veined. On dry prairies, Mo. and Kans. 

 to Tex. May-July. 



11. Pentstemon grandiflorus Nutt. Large-flowered Beard-tongue. 

 (I. F. f. 3256.) Somewhat glaucous, stout, 6-12 dm. high. Leaves entire, obtuse, 

 the basal obovate, narrowed into broad petioles, those of the lower part of the stem 

 sessile, oblong or oval, 2.5-6 cm. long, the upper nearly orbicular, cordate-clasp- 

 ing, shorter; thyrsus open, leafy-bracted, the bracts orbicular, cordate; calyx- 



ts lanceolate, acute, 6-8 mm. long; corolla lavender-blue, the tube dilated 

 above the calyx, the limb somewhat 2 lipped; sterile filament incurved, villous 



