102 NORTH AMERICAN FLORA [VOLUME 33 
9. OLIGANTHES Cass. Bull. Soc. Philom. 1817: 10. 
1817; 1818: 58. 1818. 
Dialesta H.B.K. Nov. Gen. & Sp. 4: 44. 1818. 
Shrubs or small trees, with broad, alternate, petiolate, tomentose leaves. Heads 1-8- 
flowered, aggregated in dense corymbiform panicles terminating the stem and branches. 
Involucre cylindric or narrowly campanulate; involucral scales few, membranous or scarious, 
imbricate in several series. Receptacle subconvex, naked. Corolla tubular, regular, the 
limb deeply 5-cleft. Anthers sagittate, obtuse at base. Style-branches slender. Achenes 
striated or ribbed. Pappus typically in two series, the inner or both sometimes caducous, of 
linear flat scales, twisted toward the apex, or of scales more or less united into a cup. 
Type species, Oliganthes triflora Cass. 
Lower leaf-surface tomentose; middle involucral scales obtuse or rounded. 1. O. discolor. 
Lower leaf-surface glabrous, the veins alone pubescent; middle involucral 
scales sharply acute or acuminate. 2. O. ferruginea. 
1. Oliganthes discolor (H.B.K.) Schultz-Bip. Linnaea 
203) 502: 18472 
Dialesta discolor H.B.K. Nov. Gen. & Sp. 4:45. 1818. 
Tall shrub or small tree; twigs closely cinereous-tomentose; leaf-blades thin, elliptic, 
10-18 cm. long, 4.5—6 cm. wide, acuminate, entire, narrowed at base, dark-green and essenti- 
ally glabrous on the surface above, puberulent on the veins, closely and thinly white- 
tomentose on the surface and brown-tomentose on the veins and veinlets beneath; 
lateral veins curved-ascending, veinlets conspicuously reticulate; petioles 15-25 mm. long, 
somewhat dilated below into a base 2-3 mm. wide; inflorescence irregularly branched, tomen- 
tose; heads 2-flowered, on peduncles 3-4 mm. long; involucre narrowly campanulate to 
subcylindric, 5 mm. high; scales pale-green or brownish-green, frequently purple at tip, 
closely appressed, concave or trough-shaped, the outermost semicircular, rounded, the inner 
progressively longer to oblong-elliptic, obtuse or rounded, the innermost subacute, all thinly 
short-ciliate, glabrous on the back, or the innermost minutely puberulent; achenes obconic, 
plump, flat on one side, 10-striate, 2 mm. long; inner pappus-scales about 5, pale-brown, flat, 
3.5 mm. long; outer pappus-scales 5-10, about 0.3 mm. long. 
TYPE LOCALITY: Colombia. 
DISTRIBUTION: Panama and Colombia. 
ILLUSTRATION: H.B.K. Nov. Gen. & Sp. pl. 320. 
2. Oliganthes ferruginea Gleason, sp. nov. 
Tall shrub or small tree, 10-12 m. high, 20-30 cm. in diameter; twigs closely ferruginous- 
tomentose; leaf-blades elliptic, 10-15 em. long, 3—5.5 cm. wide, acuminate, entire, narrowed 
to an acute base, slightly rugose and essentially glabrous on the surface or occasionally puberu- 
lent on the midvein above, resinous and essentially glabrous on the surface beneath and 
tomentulose along the veins; petioles 10-15 mm. long, barely dilated at base; inflorescence 
irregularly branched, tomentose, with numerous 2-flowered heads on short peduncles; involu- 
cre narrowly turbinate-cylindric to ellipsoid, 7 mm. high; scales pale-brown, appressed, the 
outer depressed-triangular, broadly acute, arachnoid-ciliate, the inner progressively longer, 
entire or minutely ciliate at the middle to conspicuously arachnoid-ciliate toward the sharply 
acute or acuminate tip, glabrous on the back or thinly pubescent apically; achenes obovoid, 
2 mm. long, 2-striate on the flat ventral side, 8-striate on the convex dorsal side; inner pappus- 
scales about 5, easily deciduous, 3.5 mm. long, pale-brown, flat, somewhat twisted, minutely 
ciliate; outer pappus scales 5-10, nearly white, scarious, about 0.3 mm. long, ovate-triangular, 
fimbriate. 
Type collected in the forests of Alto de Mano Tigre, Diquis valley, Costa Rica, altitude 700 
meters, H. Pittiey 12138, sheet 1 (U.S. Nat. Herb no. 577547). 
DISTRIBUTION: Costa Rica. 
EXCLUDED SPECIES 
OLIGANTHES OXYLEPIS Benth.; Benth. & Hook. Gen. Pl. 2: 233. 1873. 
