annual; the stem simple and more or less branched at the summit; the
leaves opposite, ovate or suhcordate, acuminate, doubly or unequally serrate,
3-nerved, hirsute-canescent or pubescent beneath, somewhat scabrous, on
long petioles. Heads small, greenish, ebracteate, sessile and often glomerate,
disposed in compound terminal and axillary spikes, forming a pyramidal
panicle.
C. xanthiifolia (Fresenius, 1. c.)—lva xanthifolia, N u tt.! gen. 2. p. 185.
I. (Picrotus) xanthifolia & paniculata, Nutt.! An trans. Amer. phil. soc. (n.
ser.) 7. p. 347.
In alluvial soil, Upper Missouri near Fort Mandan &c., Nuttall ! Prince
Neu-uiied (seeds from which the plant was raised in the Frankfort Botanic
Garden) to the Rocky Mountains, Nuttall!—Scales of the involucre somewhat
hairy externally and ciliate, distinct, as long as the disk. Ovaries
minutely somewhat hairy at the summit when young, at length glabrous;
the corolla reduced to a minute ring surrounding the base of the style.—We
are not sure that the plant is truly polygamo-dicecious, since the styles, in
what Mr. Nuttall considers the sterile plant, are apparently perfect: the fertile
ovaries of lva ciliata are at first very small likewise : but in this plant
the inner involucral scales are also proportionally reduced in size, so as to be
readily overlooked, as indeed they have been by Mr. Nuttall. We have a
specimen from a plant cultivated in Mr. Lambert’s garden, exhibiting the
heads in a somewhat monstrous state; the styles of the fertile flowers frequently
3 or 4, and those of the exterior sterile 2-cleft; the former showing
an evident corolla; the corolla of the disk-flowers 10-nerved ; the receptacle
towards the margin furnished with dilated and somewhat cucullate chaff;
while in the wild plant the chaff is often nearly or quite wanting.—Excepting
its entire opposite leaves, this plant has the habit as well as the inflorescence
and many of the characters of Euphrosyne, DC. (DeLess. ic. 4. t.
28); of which, indeed, it might be deemed a section, should that genus
prove to have an inner series of involucral scales, similar to that which is represented
in the figure as one of the pale® of the receptacle.
78. IYA. Linn.; Gartn.fr. t. 164 ; DC. proclr. 5. p. 529.
Fertile and sterile flowers in the same heads ; the former few (1-5), marginal,
with a small tubular corolla ; the latter several (7-20, rarely only 2 or
3), with a tubular-campanulate or infundibuliform 5-toothed corolla. Scales
of the campanulate or hemispherical involucre 3-5 in a single series, and often
more or less united, or 6-9 and imbricated, usually ovate or orbicular
and somewhat fleshy. Receptacle small, chaffy ; the chaff linear or spatu-
late. Anthers sometimes with a mucronate inflexed appendage, distinct or
nearly so. Style in the fertile_flowers deeply 2-cleft; the branches linear or
linear-subulate, one of them often imperfect; in the sterile flowers undivided,
usually with the apex radiate-penicillate. Achenia obovoid, somewhat
obcompressed, wholly destitute of pappus; the sterile flowers with rudimentary
ovaries.—Herbaceous or shrubby commonly maritime (American)
plants. Leaves opposite or the upper alternate, often thick or fleshy, 1-3-
nerved. Heads solitary or ternate in the axils of the tipper leaves, or of fo-
liaceous bracts, forming spikes or spicate racemes, deflexed. Corolla greenish
white. Anthers yellow.
§ 1. Involucre several-flowered, composed, of 3-5 distinct and nearly 1-seriate,,
or partly united scales. *
1. I. ciliata (Willd.): annual, hirsute or hispid, branched; leaves opposite,
on slender hispid or ciliate petioles, ovate, acuminate, coarsely and irregularly
serrate-toothed, scabrous above, softly pubescent or slightly canes-
cent beneath; the upper ones ovate-lanceolate; spikes dense, elongated,
paniculate; the conspicuous lanceolate or ovate-lanceolate bracts, and the
(3-4, distinct) roundish unequal scales of the involucre, hispidly ciliate ; fertile
flowers mostly 3; chaff of the receptacle linear-filiform.— Willd. spec. 3.
p. 2386; Pursh, fl. 2. p. 580 ; DC. 1. c. , I. annua, Michx. ! fl. 2. p. 184,
not of Linn. Ambrosia (vel lva) Pitcheri, Torr.! mss. {in herb. Hook.);
Hook, compan. to hot. mag. 1. p. 99.
0. bracts linear and much elongated, ciliate only near the base.—Ambrosia
Pitcheri /?., Hook. 1. c.
Swamps and moist places, Illinois! and Missouri! to Louisiana ! Arkansas!
and Texas! common. Aug.-Oct.—Plant 2-6 feet high, coarse and
weed-like in appearance, with much the habit of an Ambrosia. Leaves 3-4
inches long. Spikes 3-6 inches long, numerous; the bracts longer (in 3.
many times longer) than the deflexed almost sessile heads. Scales of the
involucre 3, rarely 4 or 5, very obtuse, unequal. Fertile flowers sometimes
4 or 5, inconspicuous when young ; the corolla slender, truncate. >• Achenia
obovate, lenticular. Sterile flowers 10-15, greenish ; the style penicillate at
the apex.
2. I. frutescens (Linn.): shrubby, nearly glabrous, much branched; leaves
opposite or the upper ones alternate, a little fleshy, oval or lanceolate, somewhat
scabrous, coarsely and sharply serrate ; the uppermost, or bracts, linear
lanceolate, entire; heads depressed-globose, somewhat pedicellate, solitary
or in pairs in the axils of the bracteal leaves, forming foliaceous paniculate
racemes ; scales of the involucre 5, orbicular, glabrous, distinct; fertile flowers
5; chaff of the receptacle linear-filiform.—L in n .! amcen. acad. 3. p. 25,
£■ spec. 2. p. 989 ; Walt. ! Car. p. 232 ; Lam. ill. t. 166. ƒ. 2 ; Michx.! fl.
2. p. 184 ; Willd. 1. c .; Pursh! fl. 2. p. 580; Ell. sk. 2. p. 475 ; Bigel. fl.
Bost. ed. 2. p. 317; DC.! 1. c.
Sea-coast, and muddy shores of large rivers near the ocean, Massachusetts
! to Florida! and Louisiana; common. July-Sept.—Shrub 3-8 feet
high; the stems annually dying down to near the ground in the Northern
States. Leaves of a greyish hue, sometimes ternate. Heads recurved,
greenish. Corolla of the fertile flowers very small, 2-3-toothed. Achenia
when young sprinkled with resinous dots as in most other species.—Marsh
Elder.
3. I. axillaris (Pursh): much branched from the somewhat ligneous base,
low, covered with minute appressed-hairs or nearly glabrous ; leaves alternate
or the lower opposite, fleshy, lanceolate-linear, oblanceolate, or spalu-
late-oblong, entire, obscurely 1-3-nerved, narrowed at the base, sessile;
heads solitary in the axils of the leaves, on short recurved pedicels; scales
of the campanulate involucre 4-5, distinct, or united to the middle; fertile
flowers 4-5; chaff of the receptacle filiform-linear.—Pursh! fl. (suppl.) 2.
p. 743; Nutt. ! gen. 2. p. 185 ; Hook.! fl. Bor.-Am. 1. p. 309, t. 106. I.
axillaris & I. foliolosa, Nutt.! in trans. Amer. phil. soc. (n. ser.) 7. p. 346.
Dry sandy and saline soil, Upper Missouri, Bradbury! Nuttall! Mr.
Nicollet! Saskatchawan, Drummond! &c. and on the Oregon from the
Rocky Mountains to, the Grand Rapids, Douglas ! May-July.—Root annual
according to’ Pursh and Hooker, ‘perennial & herbaceous,’ Nuttall,
certainly perennial or even ligneous in the fine specimens collected by Mr.
Nicollet. Stems ascending, a span to a foot high; the plant with much the