MINT FAMILY 525 
lance-shaped, rather coarsely toothed, the teeth sharp, toward the base 
the border plane, 14 to 3 in. long, tapering at each end, on short Jeaf- 
stalks. Shady moist grounds. July-Sept. 
2. L. sessilifolius, Gray. SESSILE-LEAVED WaTeR Hoarnounp. Stem 
stout, 4-angled, smooth or slightly downy above; leaves without leaf- 
stalks, coarsely dentate, lance-shaped or narrowly egg-shaped, 1 to 2 in. 
long; calyx teeth awl-shaped, rigid. Moist soil. Aug.-Oct. 
3. L.rubellus, Moench. (Fig. 2, pl. 131.) Srarkep WATER Hoar- 
HOUND. Stem 4-angled, angles not acute, smooth or nearly so; leaves 
lance-shaped, coarsely toothed at margins, except toward the base, on leaf- 
stalks. Calyx teeth less acute than in No. 2. Southern part of our 
region. Aug.-Oct. 
4. L. americanus, Muhl. (Fig. 1, pl. 131.) CuT-LEAVED WATER 
Hoarnounp. (L. sinuatus, Ell.) Stem acutely 4-angled, 1 to 2 ft. high; 
leaves on leaf-stalks, lance-shaped or oblong, the margins deeply incised, 
the teeth sharp, tapering at each end. Calyx teeth awl-shaped. Wet 
soil. June-Oct. 
5. L. europaeus, L. (Fig. 4, pl. 131.) Water Hoarnounp. More 
or less downy, stems branching, 1 to 23 ft. high; leaves egg-shaped on 
short leaf-stalks, margins with very coarse teeth; calyx teeth narrow 
lance-shaped. Found naturalized in a few places, southern part of our 
area. July-Sept. 
¢ Corolla 2-lipped, upper lip plane or concave; stamens 4 straight or di- 
vergent, anterior (lower) pair longest 
s. THYMUS, IE. 
Perennial herbs, or creeping shrubby plants, with opposite smooth- 
margined leaves and with flowers in dense terminal clusters, or some- 
times in the upper leaf-axils. Corolla distinctly 2-lipped, the upper one 
flat and nearly straight, slightly notched at apex; calyx egg-shaped, with 
3 long, lance-shaped teeth and 2 short ones, 13-nerved; stamens 4, lower 
pair longest, the 2 longer extending beyond the upper lip of the corolla. 
T. serpyllum, L. (Fig. 5, pl. 131.) Witp Tuyme. Stems creeping, 
slender, much branched, 4 to 12 in. high, usually forming dense mats. 
Leaves oblong rounded at apex, somewhat tapering at base, edges entire. 
Flowers in terminal clusters and sometimes in axillary whorls. Natu- 
ralized in places, in woods, thickets and roadsides. June-Sept. 
4. HYSSOPUS, L. 
Erect herb, with erect, scarcely branching stem and with linear leaves, 
entire at borders, and blue or purple flowers in dense clusters in the upper 
axils. Calyx tubular, 15-nerved, equally 5-toothed; corolla short, 2-lipped, 
upper lip flat, erect, notched, lower 3-lobed, the middle one much the 
longer and 2-cleft. Stamens 4, diverging, all extending beyond the corolla, 
H. officinalis, L. (Fig. 7, pl. 131.) Hyssor. Naturalized, roadsides 
and waste places. June-Oct. 
