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Published In: American Journal of Science, and Arts 42(1): 45. 1842. (Amer. J. Sci. Arts) Name publication detailView in BotanicusView in Biodiversity Heritage Library

Project Name Data (Last Modified On 8/25/2017)
Acceptance : Accepted
Project Data     (Last Modified On 7/9/2009)
Status: Native


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1. Pycnanthemum albescens Torr. & A. Gray (white mountain mint)

Pl. 439 j, k; Map 1982

Stems 40–90(–150) cm long, pubescent on the angles and sides with a mixture of moderate to dense, short, curled hairs and sparser, longer, spreading hairs. Leaves sessile or short-petiolate, the largest leaves with the petioles 4–12 mm long. Leaf blades 2.5–7.0 cm long, 15–25 mm wide, ovate to broadly lanceolate or narrowly elliptic, angled or tapered at the base, the margins often finely toothed; the upper surface of the lower and median leaves sparsely to densely short-hairy and usually somewhat grayish, that of the uppermost leaves usually whitened with dense, short, curled hairs; the undersurface of all of the leaves pale or whitened with dense, short curled hairs and occasionally with a few longer, spreading hairs along the veins. Inflorescences relatively open, often appearing broadly rounded, the branches mostly observable, at least at fruiting. Bracts leaflike, whitened with dense, short, curled hairs on usually both surfaces. Bractlets 2–4 mm long, linear to narrowly lanceolate. Calyces 3.5–5.0 mm long, zygomorphic, 2-lipped, densely pubescent with minute, appressed hairs, lacking longer bristly hairs on the margins or tip, the upper lip shallowly 3-lobed, the lobes 0.4–0.6 mm long, triangular, bluntly pointed, the lower lip more deeply 2-lobed, the lobes 1.0–1.5 mm long, ovate to oblong-ovate, bluntly pointed. Corollas 5–8 mm long, white to pale lavender. Nutlets 1.0–1.4 mm long, hairy toward the tip. 2n=38. July–September.

Scattered mostly in the Ozark and Mississippi Lowlands divisions (Kansas to Texas east to Kentucky and Florida). Mesic to dry upland forests, savannas, sand prairies, ledges of bluffs, and acid seeps; also pastures and old fields.

Where this species grows in proximity to P. muticum and P. pilosum, rare putative hybrids have been collected. E. Grant and Epling (1943) noted the existence of two races within P. albescens, with plants in the Gulf Coastal portion of the species range having stems with uniformly short, curled hairs, this pubescence type grading into plants with a mixture of such shorter hairs and longer, spreading ones. Missouri plants are typical of the latter race.



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