8 PROCEEDINGS OF THE AMERICAN ACADEMY. 
or denticulate, narrowed below to a somewhat petiole-like base, decur- 
rent upon the stem, sparingly pubescent above, tomentulose and gland- 
ular-atomiferous beneath, at length somewhat glabrate: inflorescence q 
loose ; heads 2 em. high, about 20-flowered. — Nov. Veg. Desc. fase. 1, 
27 (1824), not Sessé & Mocifio.— Micnoacan: near Vallisoletum, 
flowering in October and November, Lexarza, GUERRERO: vicinity of 
Acapulco, Palmer, no. 144 (hb. Gr.). 
ee 
+ + Outer bracts of the involucre elliptical or spatuiate, two-thirds as long as the 
inner ; the latter glandless. 
= 4. T. pterocaulis, n. sp. Stems much branched ; ultimate branch- 
lets subappressed-pubescent: leaves thin, ovate to ovate-lanceolate, 3 to 
10 em. long, 1.5 to 4 em. broad, acute, mucronate, entire or denticulate, 
sessile and decurrent upon the stem or narrowed to a short petiole-like 
base, glabrous or nearly so above, sparingly pubescent beneath: inflores- 
cence loose and comparatively few-headed ; heads 1.7 to 2 em. high, 12- 
14-flowered ; bracts of the proper (inner) involucre 8, linear-oblong, ob- 
tusish or abruptly pointed at the tip, appressed-pubescent. — CoLiMa : 
Manzanillo, December, 1890, Palmer, no. 897 (hb. Gr.). 
+ + + Outer bracts of the involucre 5, very large, ovate-lanceolate, copiously 
dular. 
ER SS SES RR ey te May 
_ 5. T. alata, D.Don. Stems erect, rigid, branching ; branches terete, 
foliaceous-winged : leaves oblong-ovate, 5 to 8 em. long, 2.6 to 4 cm. | 
broad, acute, mucronate, denticulate, papillose-setose on both surfaces: : 
bracts of the outer involucre 2.5 to 4 em. long, about 12 mm. broad, q 
longer than the proper involucre: heads 24-flowered. — Trans. Linn. 4 
Soe. xvi. 192; DC. Prodr. vii. pt. 1,68; Hemsl. Biol. Cent.-Am. Bot. ii. 
_258.— Mexico : without locality, Sessé & Mocifio. 
* * * Leaves subsessile or narrowed to a shortly petioled base : stem wingless , 
(sometimes very narrowly and inconspicuously winged in 7. rugulosa). q 
+ Bracts of the outer involucre 5, large, foliaceous, ovate, usually exceeding the 
inner. 
> 6. T. longifolia, D. Doy. Stems erect, leafy ; branches striate, sub- 
_ ‘appressed tawny-pubescent : leaves crowded, sessile or subsessile, lance- 
olate, 3 to 8 cm. long, 1 to 2 em. broad, acute or acuminate, entire to 
shallowly dentate, sparingly pubescent above, more or less appressed- vil- 
_ lous beneath, somewhat glabrate, usually conduplicate: inflorescence 
dense, many-headed, conspicuously glandular; heads large, 2 to 2.5 cm, 
high, 18-20-flowered. — Trans. Linn. Soc. xvi. 191 (1838) ; DC. Prodr. 
th Rapin) tet be ORT et tee ey we eC Sk 
