196 COMPOSITAE. [Erigeron. 
7. ERIGERON, L. 
Flower-heads heterogamous. Ray-fl. female, fertile, ligulate in several 
series, very narrow, either longer than the as and erect or spread- 
ing, or shorter and filiform. Disk-fl. hermaphrodite, mostly fertile, 
numerous or few. Invol. face numerous, narrow, in one or two nearly 
equal rows. Receptacle flat, naked. Style-branches narrow, with lanceolate 
appendages. Achenes sah Tecan ee of copious eapillaey, nearly 
equal bristles, mostly in a single — Herbs with alternate or radical 
leaves. Heads usually small, Seabee or paniculate, rarely solitary 
~ and mci — Ray-florets white or purple. 
A large genus ranging over the ston hse of the globe, but chiefly found in the 
veombeuate regions of the northern hemisphe 
brate; pappus whitish, twice as long as the achene . E. Canadensis. 
Canescent, W. sue broader leaves; pete. Ree 4 times as tong as . 
the achen . E. albidus. 
1. E, eee I. — An erect annual with stiff wand-like branches, 
—4 ft. high, mostly glabrate or bristly-hairy. Leaves linear-lanceolate, 
entire, 2—3‘ long, those from the base cut-lobed. Heads small cylindrical, 
2‘, numerous in leafy panicles. Invol. bracts linear-lanceolate, with sca- 
brous margins, glabrate, in 2 rows. Ray-fl. numerous, scarcely exceeding 
the mada narrow filiform, minutely ligulate, white. Disk-fl. few, 4—7; 
tubular, 4—5 toothed. Achenes short, 1/2”, ciliolate. Pappus twice as 
long, “pando whitish. 
mon weed on all islands. iohe>. Of American en but now 
sabiieitiel in most parts of the ee Raraeweey in the temperate latit 
2. E. albidus, Gray, Bonplandia, IX, 36. — A perennial, stouter than 
the preceding, canescent with short and soft hairs. Leaves broader lan- 
arger, fed in sire panicles. Invol. as before, but pubescent. 
Ray-fl. pale, very nu 8, filiform, scarcely ligulate, not exceeding the 
pappus. Disk-fl. broadly sahil: 5-toothed, few. Achenes hairy, '/, as long 
as the l-serial erect tawny pappus. — Soni yza albida, Willd. — Includes, 
according to Gray, C. erigeroides, DC. C. diversifolia, Weinm., C. chenopo- 
er DC., C. floribunda, H. B. K., Erigeron lidapmiaais: Schlecht. 
Int iced wt ith the former species, gregarious in parts of Molokai and Maui. 
A native of tropical America, but now a common weed in many countries of the warmer 
8. TETRAMOLOPIUM, Nees. 
Flower-heads obconical or hemispherical, heterogamous, radiate or sub- 
discoid. Inyol. bracts linear, with scarious margins, imbricate in 3 rows, 
Woke: of the outer row very short. Receptacle flat, naked. Ray-fl. nume 
rous In several rows, female, fertile, ligulate, the ligules either longer than 
their tubes, explanate and white, or shorter, revolute and pale purplish. 
