Xanthium.] COMPOSITAE. 201 
1. G. luteo-album, LZ. — DC. Prod. VI, 230. — Stem simple, or branch- 
ing from the base, '/2—1'/2 ft. high, white with thick wool. Leaves 
woolly on both sides, somewhat clasping, the lower obovate obtuse, the 
upper spathulate or linear, Heads in dense leafless terminal clusters, 
several clusters at the end of a stem, glomerate on short or corymbose 
on longer peduncles. Invol. bracts stramineous, in several rows, the outer 
ovate, the inner lanceolate. Hermaphrodite flowers 8—10, brownish. 
Bristles of pappus free to the base. Achenes glabrous. — G. Sandiwicen- 
sium, Gaud, Bot. Freye. p. 464. — Lessing, in pesEarte VI, 525. 
All islands, in nibaaie or rocky localities, Ragiageres of the upper regio 
«Enaena>. A co’ on plant in many cou , diffused over eal ira the stats of Europe 
and parts of ‘gh ae Africa; occurs ae in sige Se Zealand 
ureum, L.— DC. Prod. VI, 232. — An annual. Stem simple, 
or branchin m the base, t/2—1 ft. high, woolly. Leaves oblong- 
spathulate, mostly obtuse, not decurrent, green or cobwebby above, white 
with close wool underneath, the lowest 2-3‘ long and somewhat petiolate. 
Heads about 11/2” long, clustered in the axils of the upper leaves, the 
lower clusters distant, the upper forming a terminal leafy spike. mies 
bracts all linear-lanceolate (outer ones few), scarious but woolly, taw 
white. Hermaphr. fl. 2 or 3. Achenes terete. Bristles of pappus seth 
or. A 
at the base. — Gamochaeta Americana, Wedd. 
Oahu! near Diamond Hill; Hawaii, and perhaps on Seton ‘elke A ager of the 
American Continent, on which it extends, under a vari of names from the United 
States East and West to the ein extremity. Has eae ted also to Hongkong ser 
a few other places of the Old Wo ; 
Trine V. HELIANTHOIDEAE. 
Heads heterogamous and radiate, the ray-florets female, pense or 
irregular, or by defect of the ray homogamous, the florets all herm 
Anthers obtuse at the base. Style-branches of fertile florets truncate or 
appendiculate, the style in sterile florets often entire. Pappus of few 
stiff awns or short scales or none. Leaves opposite or rarely alternate. 
10. XANTHIUM, Tourn. 
Heads homogamous and unisexual, monoecious. Male heads globose, 
many-flowered. Invol. bracts few, short,and narrow. Receptacle elevated, 
paleaceous. Corollas tubular, 5-toothed. Filaments united; anthers ae 
obtuse below, mucronate at the top. Style rudimentary, undivided. Fema 
heads 2-flowered. Inyolucre united and closed, ovoid, covered with hoo oe 
Sepa 2-beaked, 2-celled. Corollas wanting. Style- a exserted 
Achenes without pappus, enclosed within the h hardened 
ates inyolucre. — Coarse scabrous annuals, armed or unarmed, with 
