232 NORTH AMERICAN FLORA [VoLuME 34 
ILLUSTRATIONS: Curt. Fl. Lond. 5: pl. 63 [2: pl. 180]; Engl. Bot. pl. 1232; Baxter, Brit. Bot. 
pl. 335; Fl. Dan. pl. 1764; Sv. Bot. pl. 50; Schkuhr, Handb. pl. 253b; Hayne, Arzn. Gew. 1: pl. 3; 
Guimp. & Schechtl. Abb. Pharm. Boruss. pl. 122; Reichenb. Ic. Fl. Germ. 16: pl. 997, f. I; Fl. Deuts. 
ed. 5. pl. 3049; Coste, Fl. Fr. f. 1947; Britt. & Brown, Ill. Fl. f. 3994; ed. 2. f. 45067. 
5. Chamomilla Courrantiana (DC.) C. Koch, Linnaea 24: 338. 
1851. 
Matricaria Courrantiana DC. Prodr. 6: 52. 1837. 
Matricaria pyrethroides DC. Prodr. 6: 52. 1837. 
Matricaria Chamomilla coronata Boiss. Voy. Bot. Esp. 2: 316. 1840. 
Matricaria coronata J. Gay; Koch, Syn. Fl. Germ. ed. 2.416. 1843. 
A leafy annual; stem 2-4 dm. high, slender, branched, glabrous; leaves 4-6 em. long, 
bipinnatifid into narrow filiform divisions, glabrous; heads solitary at the ends of the branches, 
radiate; involucre about 2.5 mm. high, 6-§ mm. broad; bracts in 2 series, oblong or elliptic, 
rounded at the apex, broadly scarious; receptacle conic, acute, hollow; ray-flowers 10-15; 
ligules white, about 6 mm. long, 2 mm. wide; disk-corollas about 2 mm. long; tube equaling 
the campanulate throat; achenes elliptic, with 5 slender ribs on the inner side, smooth on the 
back and between the ribs; pappus of a membranous, erose or fimbriate crown, sometimes 
0.5 mm. long. 
TyPE LocaLity: Teneriffe. 
DISTRIBUTION: Texas to Arizona, Sinaloa, Zacatecas, and Mexico (state); Bolivia; adventive 
from Spain. 
ILLUSTRATION: Webb & Berth. Hist. Nat. Canar. pl. 89. 
6. Chamomilla suaveolens (Pursh) Rydberg. 
Santolina suaveolens Pursh, Fl. Am. Sept. 520. 1814. 
Artemisia matricarioides Less. Linnaea 6: 210. 1831. 
Cotula matricarioides Bong. Mém. Acad. St.-Pétersh. VI. 2: 147. 1832. 
Tanacetum suaveolens Hook. Fl. Bor. Am. 1: 327. 1833. 
Matricaria discoidea DC. Prodr. 6: 50. 1837. 
Tanacetum pauciflorum DC. Prodr. 6: 131. 1837. Not T. pauciflorum Richards. 1823. 
Matricaria tanacetoides Fisch. & Mey. Ind. Sem. Hort. Petrop. 7: 52. 1840. 
Lepidanthus suaveolens Nutt. Trans. Am. Phil. Soc. II. 7: 397. 1841. 
Cenocline pauciflora C. Koch, Bot. Zeit. 1: 41, in part. 1843. 
Lepidotheca suaveolens Nutt.; T. & G. Fl. N. Am. 2: 413, as synonym. 1843. 
Tanacetum matricarioides Less.; Ledeb. Fl. Ross. 2: 544, as synonym. 1846. 
Akylopsis suaveolens Lehm. Ind. Sem. Hort. Hamb. 1850: 3. 1850. 
Chamomilla discoidea J. Gay; A. Br. Bot. Zeit. 10: 650. 1852. 
Matricaria matricarioides Porter, Mem. Torrey Club 5: 341. 1894. 
Matricaria suaveolens Buch. Fl. Brem. ed. 4. 142. 1894. Not M. suaveolens ,. 1755. 
A leafy annual; stem !—3 dm. high, striate, branched, glabrous; leaves 2-4 cm. long, 
glabrous, bi- or tri-pinnatifid into short linear-filiform divisions; heads numerous, discoid; 
involucre saucer-shaped, 3 mm. high, 5-8 mm. broad; bracts in 2-3 series, subequal, elliptic, 
rounded at the apex, with white, scarious margins; receptacle conic, hollow; ray-flowers wanting; 
disk-corollas greenish-yellow, 1.5 mm. long; tube slightly longer than the campanulate throat; 
lobes 4, ovate; achenes greenish-brown, oblique, with 4 ribs on the inner side, smooth on the 
back and between the ribs; crown of the pappus minute or obsolete. 
TYPE LOCALITY: Banks of the Kooskoosky [Clearwater River, Idaho]. 
DISTRIBUTION: Native from Alaska to Montana, Arizona, and Lower California; naturalized 
eastward to Newfoundland, New Jersey, and Missouri; also in eastern Siberia; adventive in Europe. 
ILLusTRaTIONS: Hook. Fl. Bor. Am. p/. 110; Reichenb. Ic. Fl. Germ. 16: pl. 997, f. II; Fl. 
Deuts. ed. 2. pl. 3050; Britt. & Brown, Ill. Fl. f. 3995; ed. 2. f. 4568. 
7. Chamomilla occidentalis (Greene) Rydberg. 
Matricaria occidentalis Greene, Bull. Calif. Acad. 2: 150. 1887. 
A very leafy stout annual; stem 3-7 dm. high, angled, branched; leaves 3-6 dm. long, 
glabrous, bi- or tri-pinnatifid, with linear-filiform fleshy segments; heads in leafy corymbs, 
discoid; involucre saucer-shaped, 4 mm. high, 8-12 mm. broad; bracts subequal, in 2-3 series, 
elliptic, rounded at the apex, with white scarious margins; receptacle conic, acute, hollow; 
ray-flowers wanting; disk-corollas greenish-yellow, 1.5 mm. long; tube somewhat gibbous, 
longer than the campanulate throat; lobes 4, ovate; achenes 1.5 mm. long, 4-angled on the 
