series, more or less subtended with foliaceous bracts, shorter than the disk.
Rays very narrow, rigid, exserted, but inconspicuous. Achenia fully a third
of an inch long, about the length of the rigid expanding pappus ; the bristles
of which are barbellate-scabrous (more so than the preceding), some of them
very obscurely thickened towards the apex.—The exterior covering of the
fruit, or calyx-tube, as in the whole genus, is readily separable from the
proper ovary.
§ 2 . Heads smaller and fewer-flowered: the involucre scarcely bracteate ; the
rays manifest, and usually fertile.—H omopappus, Nutt. (excl. spec.)
* Heads hemispherical: involucre imbricated in 3 series, shorter than the disk: achenia
sparsely hirsute.
3. P. racemosa: stem glabrous, bearing several (3-7) racemose heads at
the summit; the peduncles and the ovate-oblong scales of the involucre
pubescent; leaves glabrous, lanceolate, slightly spinulose-serrate; the upper
acute, oblong-lanceolate, partly clasping; the lower tapering to the base,
somewhat petioled ; corolla of the disk shorter than the pappus.—Homopappus
(Mvrianthus) racemosus, Nu tt.! in trans. Amer. phil. soc. 1. c. p. 332.
Plains of the Wahlamet, Nuttall!—Plant 12-18 inches high. Entirely a
Pyrrocoma; but the heads reduced in size (less than an inch in diameter);
the involucre of fewer scales, and not subtended by leafy bracts ; the rays
(15-20) rather conspicuous and fertile ; and the achenia hairy.
* * Heads obovoid, sessile and often clustered: involucre as long as the disk; the scales
linear-oblong, with short distinct herbaceous tips, imbricated in several series: achenia
glabrous. (Intermediate between Pyrrocoma and Aplopappus.)
4. P. paniculata: glabrous; stem branched at the summit; the heads
sessile and somewhat clustered along the branches, about the length of the
bracteal leaf; scales of the involucre oblong, obtuse, mucronate ; rays 10-12,
slender; young achenia slightly hairy towards the summit; leases oblong-
lanceolate, mucronate, obscurely and remotely serrulate; the cauline partly
clasping.—-Homopappus paniculatus, Nutt.! 1. c.
Plains of the Oregon near Walla-wallah, in wet places, Nuttall!—Plant
a foot high; the leaves (entirely like a genuine Pyrrocoma) and involucres,
as also in the following species, often slightly covered with a resinous exudation.
Heads numerous, more than half an inch long; the rays fertile.
5. P. arguta: glabrous; heads axillary and terminal, clustered, sessile;
scales of the involucre lanceolate, acute ; rays 10-12 ; leaves spatulate-lan-
ceolate, somewhat acuminate, sharply serrate, the cauline partly clasping.
Nutt.—Homopappus argutus, Nutt.! 1. c.
Plains of the Oregon, with the preceding, Nuttall!—Very similar to the
following, according to Nuttall: it appears to us more closely to resemble the
preceding species. The rays in the specimens which we have examined are
entirely neutral.
6. P. glomerata: glabrous; stem simple or branched; the heads (short)
clustered and disposed in an interrupted spike; scales of the involucre oblong,
obtuse; rays 8-10; leaves oblong-lanceolate, the lower spatulate-lanceolate,
very acute, mostly entire ; the cauline partly clasping.
Plains of the Oregon, with the preceding, Nuttall!—Heads nearly as
broad (half an inch) as long. Rays fertile.
49. PRIONOPSIS. Nutt, in trans. Amer. phil. soc. (n. ser.) 7. p. 329.
Heads broadly hemispherical, many-flowered ; the rays numerous (in a
single series), ligulate, pistillate ; those of the disk tubular, perfect, but more
or less infertile. Scales of the involucre very numerous, lanceolate, cuspidate,
somewhat unequal, the exterior squarrose and foliaceous. Receptacle
broad and flat, slightly alveolate. Corolla of the disk slightly dilated upwards,
5-toothed. Appendages of the style in the disk-flowers lanceolate-
oblong, obtuse, rather short. Achenia short, very glabrous, somewhat striate,
turgid; in the ray oval; in the disk cylindrical-oblong, or the infertile oblong-
linear. Pappus deciduous, composed of copious and very unequal rigid
scabrous bristles ; the inner series (5-10) setose and stronger than the others,
longer than the corolla (of the disk) and much longer than the achenia; the
others successively shorter and more slender.—Stout biennial plants, with
the aspect and spinulose-toothed leaves of Grindelia. Heads large and
showy : flowers yellow.
The short and veiy smooth achenia, and the deciduous pappus, form the chief, if
not the only distinctions between this genus and true Aplopappus: we are not sufficiently
acquainted with the South American species to judge of the importance of
these characters. The perennial species from Florida here subjoined, has short and
glabrous ovaries, but perhaps a persistent pappus: if so, this genus should probably
be considered a section of Aplopappus.
1. P. ciliata (Nutt.! 1. c .): glabrous; stem stout, » simple or sparingly
branched ; leaves elliptical, very obtuse, partly clasping, somewhat veiny,
closely and sharply serrate-toothed, the teeth all pointed with bristles.—Donia
ciliata, Nutt.! in jour. acad. Philad. 2. p. 118; Hook. exot. fl. 1. t. 45.
Aplopappus (Leiachenium) ciliatus, D C .! prodr. 5. p. 346.
Arkansas, on the alluvial banks of Great Salt River, Nuttall! Texas,
Drummond! Aug.-Oct.—Stem about 3 feet high. Involucre an inch in
diameter, som ewhat glutinous. P appus of the ray rather shorter than in the
disk, often deciduous in a ring. Inner bristles of the pappus terete, attenuate
from the base to the middle, and thence obscurely thickened upwards;
the outermost very slender and scarcely exceeding the achenia, the others
intermediate in size, &c.
2. P. 1 Chapmanii: stems simple, virgate, hirsute-pubescent; leaves erect,
numerous, narrowly lanceolate or linear, glabrous, pungently acute, seta-
ceously serrate; the radical ones elongated; the uppermost short, somewhat
hairy, appressed; scales of the involucre lanceolate, very acute or cuspidate,
squarrose; rays elongated.
Swamps in pine barrens, Middle Florida, Dr. Chapman! June-July.—
If Stem 1-2 feet high, bearing 1 to 3 or 4 heads. Leaves slightly nerved ;
the radical ones clustered, 4-6 inches long, tapering to the base, sometimes
entire ; the cauline successively decreasing in length, serrate with scattered
bristly teeth, much as in Eryngium aquaticum. Head about three-fourths
of an inch in diameter ; the involucre rather shorter than the disk. Receptacle
broad and flat, slightly alveolate and fimbrillate. Rays 30-40, narrowly
linear. Appendages of the style in the disk-flowers narrowly lanceolate,
longer than the stigmatic portion. Achenia (immature) very short.
Pappus rigid, ferruginous, nearly as in the preceding, but the bristles less
unequal.—We have not seen the mature achenia, and are not entirely sure
that the rays are yellow.