Part 103 (1/2)

from Eu.)

91. PRENaNTHES, Vaill. RATTLESNAKE-ROOT.

Heads 5--30-flowered. Involucre cylindrical, of 5 to 14 linear scales in a single row, and a few small bractlets at base. Achenes short, linear-oblong, striate or grooved, not contracted at the apex. Pappus of copious straw-color or brownish and rough capillary bristles.--Perennial herbs, with upright leafy stems arising from spindle-shaped (extremely bitter) tubers, very variable leaves, and racemose-panicled mostly nodding heads. Flowers greenish-white or yellowish, often tinged with purple; late summer and autumn. Our species belong to the subgenus _Nabalus_. The original European species has soft white pappus. (Name from p?????, _drooping_, and ????, _blossom_.)

[*] _Heads rather broad, 25--35-flowered, in a corymbose panicle._

1. P. crepidinea, Michx. Somewhat smooth; stem stout (5--9 high), bearing numerous nodding heads in loose cl.u.s.ters; leaves large (6--12'

long), broadly triangular-ovate or halberd-form, strongly-toothed, contracted into winged petioles; pappus brown. (Nabalus, _DC._)--Rich soil, Penn. and western N. Y. to Minn., and southward.--Flowers cream-color.

[*][*] _Heads narrow, 8--15-flowered, in a long raceme-like or thyrsoid inflorescence; stems simple; cauline leaves sessile; pappus straw-color._

[+] _Inflorescence p.u.b.escent, strict; heads nearly erect, 12--15-flowered._

2. P. racemsa, Michx. Stem 2--5 high, smooth and glaucous, as well as the oval or oblong-lanceolate denticulate leaves; the lower tapering into winged petioles (rarely cut-pinnatifid), the upper partly clasping; heads in crowded cl.u.s.ters; flowers purplish. (Nabalus, _DC._)--Plains, N. Maine to N. J., Mo., and northward.--Var. PINNATiFIDA, Gray, the leaves all lyrately pinnatifid. Hackensack marshes, N. J.

3. P. aspera, Michx. Stem 2--4 high, rough-p.u.b.escent, as well as the oval-oblong or broadly lanceolate toothed leaves; upper leaves not clasping; heads in small cl.u.s.ters; flowers larger, cream-color. (Nabalus asper, _Torr. & Gray_.)--Dry prairies and barrens, Ohio to Iowa, and southward.

[+][+] _Whole plant glabrous; heads nodding, 8--12-flowered; thyrse looser._

4. P. virgata, Michx. (SLENDER RATTLESNAKE-ROOT.) Slightly glaucous; stem 2--4 high, prolonged into a naked and slender spiked raceme (1{}--2 long); heads cl.u.s.tered and mostly unilateral; leaves lanceolate, acute, closely sessile, the upper reduced to bracts, the lower toothed or pinnatifid; involucre (purplish) of about 8 scales.

(Nabalus, _DC._)--Sandy pine barrens, N. J. to Va., and southward.

5. P. Mainensis, Gray. Stem 2 high, leafy; leaves as in n. 2, but the radical ovate and more abruptly narrowed to the short petiole; heads persistently drooping on slender pedicels.--St. John's River, N. Maine (_Pringle_). Perhaps a hybrid between n. 2 and 7.

[*][*][*] _Heads 5--18-flowered, racemose or paniculate, commonly pendulous; leaves variable, mostly petiolate, the lower cordate or truncate or hastate at base._

[+] _Involucre cylindrical; scales scarious-margined, the outer very short, appressed._

[++] _Pappus reddish-brown; stem tall, generally purplish._

6. P. alba, L. (WHITE LETTUCE. RATTLESNAKE-ROOT.) Smooth and glaucous (2--4 high); stem corymbose-panicled at the summit; leaves angulate or triangular-halberd-form, sinuate-toothed or 3--5-cleft, the uppermost oblong and undivided; involucre (purplish) of about 8 scales, 8--12-flowered. (Nabalus, _Hook_.)--Borders of rich woods; common, especially northward.

[++][++] _Pappus dirty straw-color or whitish; leaves very variable._

7. P. serpentaria, Pursh. (LION'S-FOOT. GALL-OF-THE-EARTH.) Nearly smooth; stem corymbose-panicled at the summit, commonly 2 high; leaves mostly deltoid, roughish; the lower variously 3--7-lobed, on margined petioles; the upper oblong-lanceolate, mostly undivided, nearly sessile; involucre (greenish, rarely purplish, sometimes slightly bristly) of about 8 scales, 8--12-flowered; flowers purplish, greenish white, or cream-color. (Nabalus Fraseri, _DC._)--Dry sandy or sterile soil, New Eng. to Va., and southward.

Var. nana, Gray. Stem more simple and strict, 6--16' high, smooth and glabrous; inflorescence contracted, the cl.u.s.ters often sessile in most of the axils. (Nabalus na.n.u.s, _DC._)--Mountains of northern N. Eng. and N. Y., and northeastward.

8. P. altissima, L. Smooth; stem tall and slender (3--7 high); the heads in small axillary and terminal loose cl.u.s.ters forming a long and wand-like leafy panicle; leaves membranaceous, all petioled, ovate, heart-shaped, or triangular, and merely toothed or cleft, with naked or winged petioles, or frequently 3--5-parted, with the divisions entire or again cleft; involucre slender (greenish), of 5 scales, 5--6-flowered.

(Nabalus, _Hook._)--Rich moist woods; N. Eng. to Minn., and southward in the mountains to Ga.

[+][+] _Involucre campanulate-oblong; secondary basal scales 2--3, linear, loose._

9. P. Bottii, Gray. Stem simple, dwarf (5--6' high), p.u.b.escent at the summit; the heads in an almost simple raceme; lowest leaves halberd-shaped or heart-shaped, the middle oblong, the upper lanceolate, nearly entire, tapering into a margined petiole; involucre (livid) 10--18-flowered, the proper scales 10--15, very obtuse; pappus straw-color.--Alpine region, mountains of Maine, N. H., and N. New York.

92. LYG.o.deSMIA, Don.