722 SCROPHULARIACEAE (FIGWORT FAMILY) 



1. P. hirsfitus (L.) Willd. Stem 2-9 dm. high, covered with fine and often 

 crowded spreading whitish mostly gland-tipped hairs ; leaves oblong to lanceo- 

 late, 5-10 cm. long, the lowest and radical ovate or oblong, usually denticulate ; 

 thyrse rather slender ; corolla dull violet or purple (or partly whitish), scarcely 

 enlarged upward^ the throat nearly closed by a villous palate ; sterile filament 

 densely bearded. (P. pubescens Ait.) — Dry or rocky grounds, centr. Me. to 

 Ga., westw. to Wise, and Mo. May-July. 



2. P. grdcilis Nntt. Stem 2-4 dm. high, minutely granular-pubescent; 

 stem-leaves mostly linear-lanceolate, the radical spatulate or oblong ; inflores- 

 cence glandular-puberulent ; corolla tubular-funnel-form or nearly cylindrical 

 with open throat, lilac-purple or whitish. — Man. and Minn, to Mo., Okla., and 

 westw. May-July. 



3. P. Cobaea Nutt. Soft-pub erulent^ 3-6 dm. high ; leaves ovate or oblong, 

 or the lower broadly lanceolate and the upper cordate-clasping, mostly sharp- 

 toothed ; thyrse short; corolla large (3.5-5 cm. long), strongly ventricose, dull 

 purple or whitish. — Prairies, Mo. and Kan. to Tex.; reported from n. O. 

 {Hacker). May, June. 



4. P. can^scens Britton. Stem erect or somewhat decumbent, 3-7 dm. high, 

 mostly simple to the inflorescence, yninutely granular-pub erulent ; leaves oblong 

 to lance-linear, the upper cordate-clasping, sometimes a little panduriform ; 

 inflorescence loosely paniculate, glandular-puberulent; corolla about 2.5 cm. 

 long, pale purplish or nearly white, icith distinct proper tube, dilated somewhat 

 ventricose throat, and ringent limb. (Including P. pallidus Small, at least in 

 part.) — Rocky banks, w. Va. to Mo. and Ga. May, June. 



5. P. albidus Nutt. Stems several from a branched caudex, erect or nearly 

 so, 2-4 dm. high, closely puberulent ; leaves lance-oblong to linear ; thyrse strict^ 

 raceme-like; calyx densely viscid-pubescent; corolla 2-2.5 cm. long, white or 

 purplish-tinged, perceptibly dilated in the throat, the limb of ample roundish 

 widely spreading lobes. — Prairies, etc., w. Minn, to Assina., south w. to Col. 

 and Tex. 



6. P. tubiflbrus Nutt. Wholly glabrous up to the glandular-puberulent inflo- 

 rescence ; stem 5-10 dm. high ; leaves oblong or ovate-lanceolate, entire or 

 sparingly toothed, the floral shorter than the remote dense clusters of the 

 virgate thyrse; corolla 1.5-2 cm. long, trumpet-shaped, with gradually dilated 

 throat and widely spreading limb, white or whitish. — Low prairies, barrens, etc., 

 Mo., Kan., and Ark.; also locally established in the Eastern States. May-July. 



7. P. laevigatus Ait. Stem 5-15 dm. high, glabrous to the inflorescence; 

 leaves rather firm, somewhat glossy, the cauiine ovate-oblong or lanceolate, 

 5-15 cm. long, with subcordate clasping base ; thyrse rather open ; calyx-lobes 

 3-7 mm. long; corolla 1.5-2.5 cm. long, white or tinged with purple, gradually 

 enlarged upward, the throat somewhat widely open but the limb scarcely 

 spreading; sterile filament thinly bearded above. (P. Pentstemon Britton.) — 

 Moist or rich soil, Pa. to Fla., and westw.; also established in fields north w. 

 June, July. 



Var. Digitalis (Sweet) Gray. Calyx-lobes 6-10 mm. long ; corolla larger, 

 2-3 cm. long, more abruptly inflated. (P. Digitalis Nutt.; P. calycosus 

 Small.) —Pa. to la., Mo., Ark., etc.; locally established northeastw. 



8. P. grandifl5rus Nutt. Glabrous and someiohnt glaucous ; stem 5-10 dm. 

 high ; leaves thickish, the upper and floral roundish, all but the obovate radical 

 ones clasping or perfoliate ; pedicels short; corolla large (4-5 cm. long), 

 ventricose-campanulate, lilac or lavender-blue ; sterile filament hooked and 

 minutely bearded at the apex. — Prairies, 111. and Wise, to Wyo. and Kan.; 

 established locally in the Eastern States. May, June. 



9. P. glaber Pursh. Glabrous; stems 3-8 dm. high; leaves mostly oblong- 

 lanceolate or the upper ovate-lanceolate ; thyrse elongated, the peduncles and 

 pedicels very short; corolla 2.4-3.7 cm. long, bright blue to violet-purple, 

 dilated above; anthers and apex of the sterile filament glabroas or sparsely 

 hirsute. — Plains of e. Neb. and s. Dak. to Wash, and N. Mex. June-Aug. 



10. P, acuminatus Dougl. Glabrous, erect or ascending, 3 dm. high ; leaves 

 thickish, firm, very smooth and somewhat glaucous, ovate-lanceolate to narrowly 



