* Corolla o f the disk very narrow, not dilated at the summit: appendages o f the style
subulate-filiform.
1 . D. sessilifiora (Nutt.): viscidly pubescent; stems simple; heads spi-
cate-racemose, often crowded ; leaves linear or somewhat lanceolate, incisely
spinulose-toothed; rays (12-15) ochroleucous.—Nutt. ! in trans. Amer.phil.
soc. (n. ser.) 7. p . 301.
Denudated plains of the Rocky Mountains and Oregon, Nuttall!—Stems
about a foot high, mostly simple, the base and lower leaves minutelv canes-
cent; the upper portion, involucre, &c. viscid. Heads rather smaller than
the following, scarcely a third of an inch in diameter, obovate or turbinate,
disposed in a close or crowded raceme or spike. Aehenia, as in the other
species of this division, narrow, canesceutly pubescent.—Very nearly allied
to the following species.
2. D. viscosa (Nutt.): pulverulently pubescent and viscid ; stems simple,
racemosely branched or somewhat corymbose; leaves linear, acute or acuminate,
incisely spinulose-toothed ; rays (18-20) purple.—N u tt.! 1. c.
With the preceding, particularly near Scott’s Bluff on the Platte, Nut-
tall.1 “ Stem simple, often very viscid, and exhaling the strong heavy scent
of Aster graveolens or Gnapbalium Americanum. Leaves sometimes nearly
pinnatifid or runcinate.” Nutt.—Scales of the turbinate involucre very
numerous, linear, rigid, with short squarrose-recurved tips.
3. D. divaricata (Nutt.): minutely canescent, not glandular or viscid ;
stem racemose or racemose-corn pound; the branches divaricate; radical and
lower leaves lanceolate or somewhat spatulate, strongly spinulose-toothed ;
the upper linear, small, often nearly entire ; rays (12—16) short, pale blue or
purple.—Nutt. ! 1. c.
Denudated plains of the Rocky Mountains and Oregon, common, Nuttall!
' About a foot high; branches rather naked, with small leaves, spreading out
into a compound corymb. Pappus fulvous or white. Nutt__The heads
are about the size of the preceding, apparently more broadly obovoid or almost
hemispherical; with rather broader, fewer, and less acute, perhaps less
rigid, caneseently puberulent (but not glandular or viscid) scales. The rays,
as in the preceding, are not much longer than the disk.—These species are
so nearly related that they may hereafter be found to pass into each other.
4. D. incana: perennial? minutely canescent throughout with a very
short soft pubescence; stem stout, racemosely branched; the branches often
elongated and corymbose, terminated by single large heads ; leaves linear,
mucronulate, entire, or frequently with a few laciniale mucronate teeth near
the base; involucre obovoid-hemispherical; the linear slightly glandular
scales imbricated in numerous series, with very acute squarrose tips; rays
(about 30) large, bright violet; aehenia narrow, canescent.—Diplopapp'us
incanus, Lindl. ! lot. reg. t. 1693 ; Hook. ! hot. mag. t. 3382: DC.! vrodr.
5. p. 278. r
. California, Douglas ! (probably from the interior.)—Stem stout, 1-2 feet
high, apparently a little woody at the base : the branches simple or somewhat
branched, ascending, racemose, becoming corymbose at the summit.
Leaves 1—2 inches long, closely sessile or slightly clasping, about 2 lines
wide ; the lower obtuse, but mucronulate, often presenting 1 to 3 or 4 slender
divaricate and mucronate teeth on each side near the base. Heads in the
wild plant about two-thirds of an inch, in the cultivated nearly an inch, in
diameter, without including the numerous and large broadly linear rays.__
This is a genuine species of Mr. Nuttall’s Dieteria, and the most showy
of the genus. The late Mr. Douglas alone seems to have met with it.
The cultivated specimens are less canescent, the branches more elongated,
the heads larger, the involucre more hemispherical, with narrower and
more squarrose scales. -
* * Appendages of the style subulate or somewhat lanceolate: pappus more slender.
5. D. caneseens (Nutt.): minutely canescent with a soft pubescence; stem
low, much branched, corymbose ; leaves linear, entire ; the radical .spatulate
; scales of the obovoid involucre lanceolate, acute, imbricated in about 4
series, with slightly squarrose lips ; rays (18-20) rather large, purplish-blue.
—Nutt. ! in trans. Amer. phil. soc. (n. ser.) 7. p. 300. Aster caneseens,
Pursh ! fl. 2. p. 547. A. biennis, Nutt. ! gen. 2. p. 155.
Upper Missouri, in denudated argillaceous soils, from the Arikarees to Fort
Mandan, Nuttall! (who alone has collected it.) Aug.-Oct.—Stem about a
foot high, divaricately branched, fastigiate at the summit, bearing numerous
heads about as large as a Daisy. Scales of the involucre rigid, canescent,
with short greenish tips. Cauline leaves closely sessile, 1 to 2 inches long,
1 to 2 lines wide. Appendages of the style subulate-lanceolate.
6. D. pulverulenta (Nutt.): somewhat caneseently puberulent; stem low,
much branched from the base, the branches fastigiate, bearing few heads on
rather naked branchlets; leaves linear or lanceolate; the lower sparingly
toothed or spinulose-serrulate ; the uppermost entire ; scales of the hemispherical
involucre lanceolate, acute, imbricated in about 3 series; rays (8- 12)
short, pale purple.—Nutt.! 1. c.
Arid plains towards the sources of the Platte, Nuttall!—About 6 inches
high. Nearly allied to the preceding; the heads smaller, the scales of the
involucre less imbricated, somewhat viscid? Appendages of the style
subulate.
§ 2. Scales of the hemispherical involucre nearly equal, imbricated in about 3
series, linear, with a short oppressed somewhat cartilaginous base, and
elongated acute spreading herbaceous tips: receptacle obscurely alveolate :
aehenia obovate, many-striate: pappus of the ray and disk nearly equal:
leaves not rigid, pinnatifid and bipinnatifid.—P apfochroma, Nutt.
7. D. coronopifolia (Nutt.): pubescent and somewhat viscid, diffusely
branched from the base; the branches mostly terminated by single (showy)
heads; radical and lower leaves bipinnatifid, petioled ; the upper pinnatifid,
with the segments toothed or incised; rays (about 20) large, reddish-purple;
aehenia villous. — Nutt.! 1. c. Chrysopsis (Pappochroma) coronopifolia,
Nutt. ! in jour. acad. Philad. 7. p. 34.
Dry naked places along streams, from the Upper Missouri and Platte to
the Rocky Mountains, Mr. Wyeth! Nuttall! July-Aug.—Root annual or
biennial ? Stems 6-10 inches high. “ Heads nearly as"large as the garden
Marigold.” Scales of the involucre with long and loose herbaceous very
acute summits. Appendages of the style subulate. Aehenia large, compressed,
but turgid, nearly as long as the pappus when mature. Pappus
reddish-brown, copious, rather rigid; the bristles in 3 or more unequal senes.
25. SERICOCARPUS. Nees, Ast. p. 148 ; DC. prodr. 5. p . 261.
Aster § Leucocoma, Nutt. (1834.)
Heads 12-15-flowered ; the ray-flowers about 5, distant, pistillate; those
of the disk tubular, perfect. Scales of the obovate-oblong or turbinate-cylindrical
involucre closely imbricated in several series, nerveless or obscurely
1-nerved; the lower portion cartilaginous (whitish), appressed; the apex