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PENTSTEMON MACKAYANUS. 



{Mr. Mackay's Pentstemon.) 

 LINNEAN SYSTEM. NATURAL ORDER. 



DIDYNAMIA ANGI0SPEK.MIA. SCROPHULARIACEiE § DIGITALS^. — (Betlth.) 



GENERIC CHARACTER. 



Pentstemon (L'Her.) Calyx 5-sepalus aut 5-partitus, bractea solitaria distante. Corolla 

 ventricosa bilabiata. Stamina didynama, rudimento quinti filiformi saepius barbato. Antherce 

 sejunctse, saepius glabra?. Capsula ovata, bilocularis, bivalvis, polysperma. Semina angulata. 

 Herbse vel suffrutices, Americana? vel Orientali-Asiaticse. Folia lajvia acuminata, ssepius ser- 

 rata. Floras paniculato-racemosi, purpurei, rosei, albidive. (Lindl.) 



Calyx 5-sepalled or 5-parted, with a solitary, distant bractea. Corolla ventricose, bilabiate. 

 Stamens didynamous, with the rudiment of a fifth, which is filiform and usually bearded. 

 Anthers separate, most frequently smooth. Capsule ovate, 2-celled, 2-valved, many-seeded. 

 Seeds angular. Herbs or under-shrubs natives of America or Eastern Asia. Leaves smooth, 

 acuminated, most frequently serrated. Flowers paniculately racemose, purple, rose-coloured, 

 or white. 



SPECIFIC CHARACTER. 



P. Mackayanus ; glanduloso-pubescens ; caule gracili ascendente ; foliis caulinis cordato- 

 acuminatis undulatis subrepando-denticulatis glabris amplexicaulibus ; radicalibus late lanceo- 

 latis petiolatis; pedunculis axillaribus oppositis multifloris in paniculam diffusam terminalem 

 dispositis ; calyce brevi segmentis ovatis acutis ; corolla compressa, labio superiore brevi inferioi'e 

 subelongato intus villoso ; filamento sterili subexserto ab apice infra medium barbato ; germine 

 glabro. 



Glandular-pubescent ; stem slender, ascending ; stem-leaves heart-shaped, acuminate, undu- 

 late, slightly-toothed, smooth, stem-embracing ; radical leaves broadly lanceolate, petiolate ; 

 peduncles axillary, opposite, many-flowered, disposed in a loose terminal panicle ; calyx short, 

 with ovate acute segments ; corolla compressed, the upper lip short, the lower one somewhat 

 elongated, hairy within ; sterile filament somewhat exserted, and bearded from the apex below 

 the middle ; germen smooth. 



Descr. — Stem terete, from twelve to fifteen inches high, clothed with short glandular hairs. 

 Leaves glaucous, exceedingly thin in texture, the upper ones cordate and stem- embracing at 

 the base, becoming gradually more attenuated as they stand lower on the stem, the lower ones 

 decidedly petiolate ; radical leaves petiolate, broadly lanceolate, attenuated at the base, and 

 gradually terminating in the margin of the pubescent petiole. Peduncles rather long, arising 

 from the axils of the leaves, and each producing from six to eight flowers. Pedicels short, which, 

 as well as calyxes and corollas, are covered with minute glandular pubescence. Calyx short, 

 with acute subreflexed segments. Corolla about an inch in length, of a fine violet blue, with a 



