(10-12) perfect, with the corolla 5-toothed, nearly destitute of proper tube.
Scales of the involucre 5 or 6, equal, concave-carinate, obovate, nearly in a
single series, membranaceous. Receptacle convex, naked. Branches of the
style truncate. Achenia of the ray and disk similar, quadrangular, tapering
to the base, hairy on the angles. Pappus of about 12 oblong obtuse nerveless
chaffy scales, distinct or slightly united at the base, much shorter than
the achenia, but almost equalling the very short corolla.—An aromatic annual
or biennial branching herb, nearly glabrous ; the branchlets glutinous.
Leaves linear ; the upper alternate, entire; the lower (often opposite) trifid
or somewhat pinnatifid ; the lobes filiform-linear. Heads corymbose, small.
Flowers yellow.
A. tenuifolia (Nutt.! 1. c.)
St. Diego, California, near the coast, Nuttall! May.—Lower leaves 2-3
inches long. Heads turbinate, 2-3 lines in diameter: the corolla of the pistillate
flowers.not longer than the perfect, both very short. Achenia and pappus
much as in Bahia and Cheenactis.—Although placed by Nuttall in Anthe-
midete, Div. Cotulete, this plant should rather find a place in the Subtribe
Heleniete.
155. TANACETUM. Linn.; Gesrtn.fr. 1.165; DC. prodr. 6. p. 127.
Heads discoid, homogamous, with the flowers all tubular and perfect, or
heterogamous ; the marginal flowers pistillate, in a single series, 3-4-toothed.
Scales of the involucre imbricated, dry. Receptacle convex, naked. Achenia
angled or ribbed, glabrous, with a large epigynous disk. Pappus either
none or minute, membranaceous, coroniform, entire or toothed, often unequal.
Herbs or suffruticose plants ; with alternate variously dissected leaves, and
solitary or corymbose (rather large) heads. Flowers yellow.
§ 1. Heads (campanulate-hemispherical) heterogamous ; the terete ray-flowers
3-toothed ; the disk-flowers 5-toothed.—E dtanacetum, DC.
1. T. vulgare(Emn.): stem herbaceous, erect, glabrous; leaves nearly
glabrous, bipinnately parted; the rachis and lobes incisely serrate; corymb
of numerous heads; inner scales of the involucre scarious at the apex, obtuse;
pappus short, equal, 5-lobed. DC.—Lam. ill. t. 696, f . 1 ; Engl. hot.
1.1229 ; Pursh, fl. 2. p. 522 ; Hook.! fl. Bor.-Am. 1. p. 327; Darlingt. ! fl.
Cest. p. 492.
(3. crispum (DC.): leaves more incised and crisped.
Naturalized abundantly in the Northern States! and Canada! July-
Sept. 11 — Tansey.
§ 2. Heads (hemispherical, the disk convex in fruit,) heterogamous ; the ray-
flowers ohcompressed, 3-5-lobed or toothed, slightly winged at the base ; the
disk-flowers 5-toothed.—I I omalotes. (Omalanthus, Less.—Omalotes,
DC.—Homalotes, Endl.)
2. T. Huronense (Nutt.): hairy or almost tomentose when young; stem
stout, herbaceous, striate-angled; leaves bipinnately divided ; the lobes oblong,
pinnatifid-incised, or often nearly entire, mucronate with a callous
point; heads (large) corymbose, or rarely nearly solitary, on stout peduncles;
inner scales of the involucre with brownish scarious margins; ray-flowers
variable, often deeply cleft on the inside, with the rounded ligule slightly
3-toothed or 3-lobed, frequently with the limb 3-5-parted; pappus short,
toothed.—Nutt.! gen. 2. p. 141, Sf in trans. Amer. phil. soc. 1. c. p. 401.
T. ? camphoratum, Less, in Linnesa, 6 p. 521. T. Douglasii, DC.! prodr.
6. p. 128. T. boreale, of the English gardens; Nutt, in trans. Amer. phil.
soc. 1. c. Omalanthus camphoratus, Less. syn. p. 260 ; Hook.! fl. Bor.-
Am. 1. p. 321. Omalotes camphorata, DC. prodr. 6. p. 83.
Shores of Lakes Huron and Superior ! north to York Factory on Hudson’s
Bay! and west to Oregon! and California!— U A stout plant, 1-3 feet
high; the heads much larger than those of T. vulgare; the disk strongly
convex in fruit. Rays slightly exserted.
§ 3. Heads (obovoid) heterogamous ; the ray-flowers (about 5) truncate, 2-3-
toothed ; the disk-flowers 5-toothed; the central apparently infertile.—
S p h -e r o m e r ia , Nutt.
3. T. capitatum: ctespitose, suffrutescent, silky-canescent; leaves clustered
on a branched caudex, cuneiform, 3-5-parted or pedate ; those of the somewhat
naked scapes nearly linear, entire or toothed at the apex ; heads numerous,
capitate ; scales of the involucre scarious ; pappus minute and irregular,
denticulate, nearly obsolete in the disk-flowers.—Sphaeromeria capitata,
N u tt.! in trans. Amer. phil. soc. (n. ser.) 7. p. 402.
Rocky Mountains, on a high hill, near the Red Butes of the Platte, towards
its northern sources on the Sweet Water, Nuttall! June.—Plant growing
in dense tufts ; the scapes 3 or 4 inches high, terminated by the spherical
cluster of heads. Corolla, especially of the exterior flowers, becoming enlarged
and indurated at the base.—Odor agreeable, like that of Chammomile.
4. T. Nuttallii: somewhat caespitose, silvery-canescent; leaves cuneiform,
obtusely 3-lobed or toothed at the apex; the lower crowded on the
branches of the woody caudex ; the upper scattered on the flowering stems ;
heads few (3—5) in a terminal capitate cluster; scales of the involucre scarious
; pappus very minute, in the disk-flowers obsolete.—Sphaeromeria
argentea, Nutt.! 1. c.
* Rocky Mountains, near the sources of the Platte and Colorado of the
"West, Nuttall! July.—Shrub 4—5 inches high. Leaves half an inch long.
Flowers bright yellow.
t Doubtful Species.
5- T. pauciflorum (Richards.): stem simple, with a single terminal head,
and sometimes another from the uppermost axil, longer than the bipinnate
and tripinnatifid villous sessile leaves; the lobes narrow, rather obtuse;
flowers all perfect. Ribhards. appx. Frankl. journ. ed. 2. p. 30 ; Hook. fl.
Bor.-Apu 1. p. 327 ; not of DC.
Woody country, between lat. 54° and 64°, Richardson__A foot high.
156. ARTEMISIA. L in n .; B e s s e r ; D C . p r o d r . 6. p . 93.
Heads discoid, few-many-flowered, heterogamous, with the central flowers
perfect (either fertile, or sterile by the abortion of the ovary,) and 5-toothed,
and the marginal pistillate in a single series, with a tubular 3-toothed corolla;
or sometimes homogamous, with the flowers all perfect. Scales of the involucre
imbricated, mostly dry and with scarious margins. Receptacle