LABIATAE (MINT FAMILY) 707 



28. PYCNANTHEMUM Michx. MOUNTAIN MINT. BASIL 



Calyx about 13-nerved, naked in the throat. Corolla short, more or less 

 2-lipped ; the upper lip straight, nearly flat, entire or slightly notched ; the 

 lower 3-cleft, its lobes all ovate and obtuse. Lower pair of stamens rather 

 longer than the upper; anther-cells parallel. Perennial upright herbs, with a 

 pugent mint-like flavor, corymbosely branched above, the floral leaves often 

 whitened ; the many-flowered whorls dense, crowded with bracts, and usually 

 forming terminal heads or close cymes. Corolla whitish or purplish, the lips 

 mostly dotted with purple. Fl. summer and early autumn. Varies, like the 

 Mints, with the stamens exserted or included in different flowers. (Name com- 

 posed of vvKvbs, dense, and &vdefwv, a blossom, from the compact inflorescence.) 

 KOELLIA Moench. 



* Calyx-teeth long, bristly-ciliate, or at least bearing long terminal bristles. 



*- Glomerules terminating the upper branches, rather densely clustered and 



forming a corymb. 



1 . P. le'ptodon Gray. Soft-pubescent, or glabrate below, loosely branched ; 

 leaves membranaceous, green, 3-6 cm. long, lanceolate or oblong-lanceolate, 

 entire or subentire, subsessile ; infloresence canescent-hirsute ; long-acuminate 

 bracts and calyx-teeth slender-subulate, villous-hirsute. O. to Mo. and N. C. 



*- +- Glomerules verticillastrate or terminating short paniculately disposed 



branches. 



2. P. clinopodioides T. & G. Pubescent; leaves short-petioled, broad- or 

 oblong-lanceolate, sharply denticulate or entire, all pale green, the upper not 

 whitened ; bracts loose, slightly ciliate ; calyx-teeth one third or one half as long 

 as the tube, sparingly bristle-tipped. (Koellia Ktze.) Dry soil, Ct. to Pa. and Va. 



3. P. pycnanthemoides (Leaven w.) Fernald. Pubescent; leaves ovate- 

 oblong, remotely toothed, the lower dark green and loosely soft-downy, the 

 floral ones whitened; cymes dense; bracts much surpassing the flowers, their 

 long awn-like points and the awn-pointed calyx-teeth (equaling the tube) bearded 

 with long loose hairs. (Koellia Ktze.; P. Tullia Benth.) Va. to Ky., and 

 southw. Sometimes too near no. 10. 



* * Calyx-teeth without long bristles (except in dubious forms of no. 10). 



- Bracts and equal calyx-teeth awn-tipped, rigid, naked, as long as the corolla; 

 flowers in dense heads mostly terminating the branchlets; leaves slightly 

 petioled. 



4. P. aristatum Michx. Minutely hoary-puberulent, 4-8 dm. high ; leaves 

 ovate-oblong and oblong-lanceolate, acute, sparingly denticulate-serrate, 2-8 

 cm. long, roundish at the base. (Koellia Ktze.) Pine barrens, N. J. to Fla. 

 and La. 



Var. hyssopifblium (Benth.) Gray. Leaves narrowly oblong or broadly 

 linear, nearly entire and obtuse. (Koellia hyssopifolia Britton.) Va. to Fla. 



*- *- Bracts and equal and similar calyx-teeth not long-awned. 



** Leaves lanceolate or linear ; heads mostly terminating the branches, subco- 



rymbosely disposed. 



= Leaves linear. 



5. P. flexubsum (Walt.) BSP. Smooth, freely branching; leaves firm; 

 heads 5 mm. or less high, somewhat downy, densely corymbose ; appressed 

 rigid bracts and lance-subulate calyx-teeth with short firm points. (Koellia 

 MacM. ; P. linifolium Pursh.) Dry ground, centr. Me. to Minn., and southw. 



= = Leaves lanceolate, 

 a. Leaves all glabrous or merely pubescent on the nerves beneath. 



6. P. virgini^num (L.) Durand & Jackson. Smoothish or minutely pubes- 

 cent, 2-10 dm. high ; leaves lanceolate or lance-linear, nearly sessile, entire, 



