larger: involucre minutely hispid. Chaff of the receptacle filiform. Mature
fruit twice as large as in A. artemisisefolia, pubescent towards the summit,
obscurely triangular at the base, entirely destitute of teeth or horns.
5. A . longistylis (Nutt.): annual, scabrous ; stem (apparently) simple;
leaves pinnatitid; the segments oblong-linear; bracts entire; fertile flowers
axillary, conglomerate, with exceedingly long styles; fruit cornute, spiny at
the summit; sterile flowers about 30, in a slightly toothed involucre; the
receptacle filiformly paleaceous; cusps of the anthers filiform. Nu tt.. m
trans. Amer. phil. soc. 1. c. p. 344. M M . .
Rocky Mountains : allied to Franseria, Nuttall.—Plant stngose-hispid.
§ 2. Sterile heads closely sessile, densely aggregated in a cylindrical sessile
spike terminating the stem or branches; the involucre turbinate, truncate,
the inner margin produced into a long and conspicuous lanceolate, hispid,
decurved or eucullate tooth or appendage : receptacle chaffy: fruit (fertile
involucre) oblong, Wangled and somewhat prismatic, solitary or clustered in
the axils of the lanceolate closely sessile 1 -nerved leaves.— C e r c o m e r is .
6. A. bidentata (Michx.): annual; stem hirsute with spreading hairs; the
branches simple ; leaves very numerous, mostly alternate, hirsute or hispid,
■partly clasping, commonly with a short spreading lobe or broad tooth on each
side near the" base, entire above, or rarely remotely serrate, acute; sterile
spike squarrose with the recurved very hispid appendage of the involucres;
receptacle small, about 10-flowered; the filiform scanous chaff much shorter
than the corolla; fruit acutely pointed; the 4 angles or ribs terminating in
short acute spines— Michx. ! fl. 2. p. 182 : Pursh fl. 2. jp. 581.
Prairies of Illinois ! Missouri! Arkansas! and Louisiana . July-aept.
Stem 1-3 feet high. Leaves 1-2 inches long. - Sterile spikes very dense ;
the appendages of the involucres, which are twice or thrice the length ot the
involucre itself appearing like recurved bracts. Fertile heads numerous,
minutely pubescent, when mature about 4 lines long, including the rigid
and sharp terminal horn or cusp. Achenium conformed to the cavity of the
involucre.
J Doubtful Species.
7 A. hismda (Pursh): canescent-hispid throughout; leaves bipinnatifid,
the segments incised; racemes terminal, somewhat paniculate. Pursh, fl.
(suvvl) 2 rp• 743.
South Carolina, Catesby (Herb. Sherard.) About a foot high: flowers
larger than in A. trifida. Pursh•
8. A . tomentosa (Nutt.): perennial; stem low; leaves bipinnatifid, the
lower side white and tomentose; spikes solitary. Nutt. gen. 2. p. 186.
Upper Missouri: rare ; 1-2 feet high. Nuttall.
81. FRANSERIA. Cav. ic. 2. t. 200; Willd. hort. Berol. t. 2 ,• DC.
Sterile heads occupying the upper portion, the fertile the base of the racemes
or spikes. S t e r i l e F l. Involucre hemispherical, composed of
8-12 united scales, 15- 20-flowered. Receptacle flatfish, chaffy; the chaff
filiform. Corolla infundibuliform, 4-5-toothed. Anthers tipped with a mu-
cronate-setigerous inflexed appendage. Ovary none: abortive style included,
radiate-penicillate at the summit. F e r t i l e F l . Involucre ovoid or oblong,
closed, covered with uncinate or spinescent prickles (composed therefore of
numerous pluriseriate united scales, each tipped with a prickle), 1-4-celled,
with a single flower in each. Corolla none, or a rudiment appressed to the
base of the style. Stamens none. Branches of the style filiform, obtuse at
the summit. Achenia oblong.—Herbaceous or suffrutescent (American)
plants, with alternate coarsely toothed or lobed, or 1-2-pinnately parted
leaves; the fertile heads somewhat aggregated at the base of the sterile spikes
or racemes; the evolution of the latter mostly centripetal! Sterile heads
ebracteate.
§ Fertile involucre (1 -celled) armed with straight spines.—C e n t r o l ^ n a ,D C .
* Perewiiial' or sujfruticose.
1. F. Chamissonis (Less.): hirsute-canescent; stems decumbent, stout;
leaves roundish-elliptical, crenate-toothed, abruptly narrowed into a long
petiole; involucre of the densely spicate sterile heads 10-12-toothed, hirsute;
spines of the fructiferous involucre short and very stout; achenia large.
F . Chamissonis a. malvaefolia, Less, in Linnaa, 5. p. 507; DC. L. c.
■ft. cuneifolia: leaves oval or elliptical, tapering by a cuneate 3-nerved
base into a long petiole;, the upper often incisely toothed. I . cuneifolia,
Nutt, .' in trans. Amer. phil. soc. (n. ser.) 7. p. 345.
Coast of California, Chamisso. ft. Mouth of the Oregon, Nuttall. Stem
(ligneous at the base, Less. ; succulent, Nutt.) 1-2 feet long.—Lessing remarks
that one of his specimens has the uppermost leaves bipinnately divided;
and in Nuttall’s specimens they are sometimes incised ; so that the following
different as it appears, may not be distinct.
2. F. bipinnatiftda (Nutt.): herbaceous; stems decumbent, villous-hirsute;
leaves silky-canescent, bipinnately divided; the ultimate segments
linear, short, obtuse, sometimes 1-2-toothed ; sterile heads in a dense spicate
raceme, with nearly glabrous 10-12-toothed (about 30-flowered) involucres;
spines of the fructiferous involucre short and very stout.—Nutt. . 1. c.
F. Chamissonis ft. pinnatisecta, Less. 1. c .; D C .! 1. c. Ambrosia pamculata,
Hook. fl. Bor.-Am. 1. p. 309, as to spec, from N. W. Coast? (but our specimen
has no flowers.) , . ,,
Coast of California, very common, Chamisso, Douglas! Nuttall! JNootka,
Dr. Scouler !
3. F. pumila (Nutt. ! 1. c.) : silky-canescent; leaves on long petioles
3-pinnatifid ; the ultimate segments linear-oblong, crowded; sterile involucres
5-7-toothed, about 12-flowered.
St. Diego, California, Nuttall /—Plant 4-6 inches high. Spike not ex-
serted beyond the leaves. "We have not seen the fruit.
4. F. discolor (Nutt.! 1. c .) : root creeping; leaves interruptedly bipinnatifid,
nearly smooth above, closely canescent-tomentose beneath; segments
subovate, acute, confluent on the wide rachis; stem short, with the lateral
branches decumbent; sterile involucres about 5-6-toothed. Nutt.
Rocky Mountains near the Colorado of the West. A very remarkable
and distinct species. Stems about a span long, slightly pubescent. Leaves
with a lanceolate outline, about 6 inches long. Fertile flowers lew: Iruit
spiny. Nuttall.—We have not seen the fully developed flowers, nor the
fruit.