270 SCROPHULARIACEiE. Pentstemon, 



Am. Acad. vi. 66; Watson, Bot. King, 219. — Rocky Mountains, Wyoming, W. Colorado, 

 and Utah, Nuttall, Hall & Harbour, Parry, Watson. 



Var. SXlflruticosUS. A span or more high from a stouter woody base : leaves from 

 spatulate to obovate and more petioled, thicker, glabrate : sepals less acuminate : corolla 

 and stamens not seen : probably a distinct species. — Utah near Beaver, Palmer, in fruit. 

 ++ ++ Leaves from narrowly linear-lanceolate with tapering base or linear-spatulate to filiform, 

 entire : stems or branches racemosely several-many-flowered. 

 = Stem herbaceous to the base, very simple, a foot or two high : corolla broad : sterile filament 

 glabrous: peduncles mostly opposite. 



P. virgatus, Gray. Minutely glandular-pruinose or glabrous : stem strict and elongated : 

 thyrsus virgate : leaves all linear-lanceolate (l\ to 4 inches long): peduncles short, 1-3- 

 flowered : sepals ovate : corolla lilac with purple veins, three-fourths inch long, abruptly 

 dilated into a broadly canipanulate funnelform throat (as wide as long), distinctly bilabi- 

 ate; the broad lips widely spreading: stamens nearly equalling the lips. — Bot. Mex. 

 Bound. 112, & Proc. Am. Acad. vi. 66. — New Mexico and Arizona, Fenc?/er, Wright, &c. 

 Inflorescence and corolla in the manner of P. secundijlorus. 



= == Stems or tufted branches mostly simple from a woody base (or herbaceous in the last 

 species), low : sterile filament longitudinally bearded : short peduncles commonly alternate. 



P. linarioides, Gray, 1. c. Cinereous, minutely pruinose-puberulent: stems much 

 crowded on the woody base, filiform, rigid, very leafy, 6 to 18 inches high : leaves 6 to 12 

 lines long, from oblanceolate-linear (at most a line wide) to nearly filiform, mucronulate; 

 the floral short and subulate : thyrsus racemiform or sometimes paniculate ; onlj' the lower 

 peduncles 2-4-flowered : pedicel shorter than the ovate or oblong acuminate sepals : corolla 

 lilac or purple, half inch or more long, with dilated-funnelform throat, less bilabiate than 

 in the preceding ; lower lip conspicuously bearded at base. — Arid grounds. New Mexico 

 and Arizona, Wright, Thurber, Parry, &c. 



Var. Sileri. A dwarf and sufEruticulose form, with smaller and fewer flowers, mostly 

 1-flowered peduncles subtended by proportionally longer floral leaves, and the lower lip 

 less bearded. — P. caspitosus, var.. Parry in Am. Naturalist, ix. 346, a much reduced form. 

 — S. Utah, Siler, Pairy. 



P. Gairdneri, Hook. Cinereous-puberulent : stems a span high, rigid : leaves linear or 

 the lower more or less spatulate, obtuse, half to full inch long : thyrsus short and simple : 

 peduncles usually one-flowered : sepals oblong-ovate, glandular-viscid : corolla half inch 

 long, narrowly funnelform, obscurely bilabiate, purple. — Fl. ii. 99 ; Gray, 1. c. — Dry inte- 

 rior of Washington Terr., Oregon, and W. Nevada. 



P. laricif olius, Hook. & Arn. Glabrous : lignescent caudex not rising above the 

 soil: leaves very slender, wlien dry filiform (the larger a fourth of a line wide, and with 

 margins revolute, an inch or less long), much crowded in subradical tufts and scattered on 

 the (2 or 5 inch long) filiform flowering stems : flowers few, loosely racemose, slender- 

 pedicelled: sepals ovate-lanceolate : corolla tubular-funnelform, half inch long; the small 

 limb obscurely bilabiate. — Bot. Beech. 376 ; Gray, I. c. — Interior of Oregon and Wyoming. 

 == = == Stems paniculatelv branching and slender, woody toward the base: corolla between 

 funnelform and salverform :" sterile filament glabrous : peduncles slender, opposite, all the upper 

 one-flowered. 



P. ambigUUS, Torr. Glabrous, a foot or two high, diffuse and often much branched : 

 leaves filiform, or the lowest linear and the floral slender-subulate : inflorescence loosely 

 paniculate: sepals ovate, acuminate: corolla rose-color and flesh-color turning to white ; 

 the rotately expanded limb oblique but obscurely bilabiate ; lobes orbicular-oval^; throat or 

 its lower side somewhat hairy : sterile filament sometimes imperfectly antheriferous. — 

 Ann. Lye. N. Y. ii. 228, & Marcy Rep. t. 16; Gray, Proc. Am. Acad. vi. 64. — Plains of E. 

 Colorado and New Mexico to S. Utah and Arizona. (Adjacent Mex.) Var. foliosus, Benth. 

 1. c, is an undeveloped state. Corolla in the typical form with a narrow and somewhat 

 curved tube and throat, of half inch in length : but it passes into 



Var. Thurberi, Gray, I.e. [P. Thurheri, Torr. in Pacif. R. Kep. vii. 15), with 

 shorter tube and more dilated throat. The two extremes of this have, in the larger forms, 

 limb of corolla half inch in diameter with tube and throat together only 3 lines long (Ari- 

 zona, Palmer, &c.); in the smallest, corolla-limb only half the size, with tube and throat 

 2 or 3 lines long (Arizona and adjacent Mex., Wislizenus, Rothrock). New Mexico, Arizona, 

 and S. Utah. 



