430 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
5. Tithonia calva Schultz Bip.; Seem. Bot. Voy. Herald 305. 1856-57. 
Mirasolia calva Benth. & Hook.; Hemsl. Biol. Centr. Amer. Bot. 2: 168. 1881. 
Gymnolomia calva A. Gray; Hook. & Jacks. Ind. Kew. 17: 1076. 1893. 
Stout branching leafy herb; stem in youth densely silky-villous with wide-spread- 
ing hairs 5 to 6 mm. long, tardily subglabrate; leaves alternate, the blades 8 to 14 
cm. long, 3.3 to 8.5 cm. wide, ovate or triangular-ovate, acute to acuminate, cuneately 
or abruptly narrowed into the cuneately margined petiole, somewhat irregularly 
serrate or serrulate with bluntish teeth, triplinerved, above densely and harshly 
glandular-tuberculate-hispidulous and rather sparsely hispid-pilose, in age subglabrate 
and lepidote, beneath slightly paler green, densely and finely glandular-hispidulous 
and especially along veins hispid-pilose with tuberculate-based spreading hairs; 
petioles 4 to 6 cm. long, margined nearly or quite to base, there usually widened into 
auricles; peduncles fistulose, spreading-hispid-pilose and finely glandular-hispidu- 
lous, 8 cm. long or less; heads 5.5 to 6 cm. wide; disk 1.7 cm. high, 2.5 to 3 cm. wide; 
involucre 3-seriate, slightly graduated, 13 mm. high, the two outer series of phyllaries 
lance-ovate (the outermost narrower), acuminate, tuberculate-hispid-pilose and 
finely tubercular, with ribbed and vittate, subindurate base and equal or shorter, 
subherbaceous, appressed apex, the innermost series oval, much broader (5 mm.), 
acute or obtusish, with appressed, subherbaceous, densely tuberculate or tuberculate- 
hispidulous and sparsely hispid-pilose apex; rays about 13, golden-yellow, oblong, 
emarginate, finely glandular-hispidulous on back, 18 mm. long, 7 mm. wide; disk 
corollas hispidulous chiefly at base of tube and on teeth, 6 mm. long (tube 0.6 mm.); 
pales firm, minutely hispidulous at the abruptly pointed but not cuspidate apex, 
9 to 10 mm. long; achenes thickened, glabrous, blackish, 3 to 3.5 mm. long; pappus 
none. 
Tyre Loca.ity: Sierra Madre of northern Mexico. Type collected by Seemann 
(no. 2045). Sketch in United States National Herbarium. 
SPECIMEN EXAMINED: 
Durango: Without definite locality, August 15, 1897, Rose 2293 (N). 
Tithonia calva is easily distinguished from the other epappose species by its usually 
acutish inner phyllaries and densely silky-villous stem. 
5a. Tithonia calva lancifolia (Robins. & Greenm.) Blake. 
Gymnolomia calva var. lancifolia Robins. & Greenm. Proc. Bost. Soc. Nat. Hist. 
29: 103. 1899. 
Stem rather sparsely tuberculate-hispid-pilose with ascending hairs 1 to 2.5 mm. long; 
leaf blades 5 to 12 cm. long, 1.8 to 4.5 cm. wide, lance-ovate to lanceolate or rarely 
ovate, acuminate, sometimes subentire, usually cuneate into the margined, often 
auriculate-based petiole, pubescent like the stem but with more incurved hairs; 
petioles 1.5 to 4 cm. long; peduncles more slender than in the type form, 2.5 to 8.5 
cm. long; heads 4.5 to 5 cm. wide; disk 9 to 12 mm. high, 12 to 22 mm. thick; involucre 
9 to 12 mm. high, 3 to 4-seriate, often more sparsely pubescent than in the typical 
form, the outer phyllaries sometimes with loose tips; disk corollas 5 mm. long; achenes 
as in the typical form. 
TYPE LocaLity: Acaponeta, Tepic. 
SPECIMENS EXAMINED: 
Teric: Tepic, 1892, Palmer 1975 (N). Acaponeta, February, 1895, Lamb 539 
(type collection; G, N). 
Distinguished from the typical form of the species chiefly by its smaller leaves, 
sparsely hispid-pilose stem, and smaller heads. 
6, Tithonia auriculata (T.S. Brandeg.) Blake, Contr. Gray Herb. n. ser. 54: 9.1918. 
Gymnolomia auriculata T. 8. Brandeg. Zoe 5: 223. 1905. 
. Herbaceous many-stemmed perennial, 30 to 50 cm. high; stems simple or sparsely 
branched, pale fuscous, striatulate, densely hispid with tuberculate-based upcurved 
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