William Trelease, Additions to the Genus Yucca: Species novae. 245 
LXIX. William Trelease, Additions to the Genus 
Yucca: Species novae. 
(Ex: Rep. Missouri Bot. Gard., XVIII [1907], pp. 225—230.) 
1. Yucca Harrimaniae var. Gilbertiana Trelease, l. c., p. 225, pl. 12. 
Acaulescent. Leaves 2 cm wide, about 45 cm long, openly concave, 
drying striate, much roughened with prominent points on both faces, 
very light or blue green appearing almost as if glaucous, with stout 
straw-colored point; margin brown, with long rather straight and stout 
pale detached fibers. Flowers about 4 cm long with 'narrow acute seg- 
ments: filaments covered with long thick white papillae: ovary seemingly 
lowpapillate, with oblong pale style. 
Western Utah, North end of Fish Spring or House Range, G. K. 
Gilbert, Aug. 4, 1901. 
A rather striking form in its very rough papillate leaves, those of 
\ the type being entirely smooth or with a few mostly low papillae near 
the apex. 
2. Yucca rostrata var. linearis Trelease, |. c., p. 226. 
Differing form the type in its narrowly linear leaves measuring 3—4 
X 40 cm,—those of the typical form being 6—12 (usually 8—10) mm 
wide. | AS 
Mexico: Coahuila, Cañons of the Sierra de Pata Salana and 
Sierra de Parras, Purpus, 1904 and 1905. Cultivated at the Missouri 
Botanical Garden. 1 
3. Yucca decipiens Trelease, |. c., p. 228. i 
Y. valida Trelease. Rept. Mo. Bot. Gard., XIII, 107—109, pl. 62—66, 
85 f. 3 (exclusive of the Lower California notes and of pl. 67, which 
refer to the true Y. valida). 
Arborescent, very rough-barked, at length sometimes 2 m thick, 
8—10 m high and openly branched above. Leaves essentially smooth, 
elongated, oblong-lanceolate, 1—(mostly 2—) 4 X 30—60.cm or more, 
ending in a usually very heavy point, finely to coarsely filiferous or 
sometimes soon denuded, with the whitish threads rather straight, the 
cluster of green leaves on mature trees nearly isodiametric. Panicle not 
pendent, short-stalked, about 1,5 m long, broadly ovoid, mostly compact, 
glabrous or with the pedicels minutely puberulous. Flowers creamy 
white: perianth segments 0,9—1,5 X 3—4 cm, one series frequently nar- 
rower- than the other: style rather short. Fruit pendent, baccate, oblong, 
2 X 6--8 cm: seeds thick, 6—7 x 7—8 mm. 
Mexico: Central table-land of Mexieo, from Durango to below San 
Luis Potosi: typically represented about Gutierrez. 
The more western representative of Y. australis, which differs 
conspicuously in its long-stalked elongated pendent panicle, though very 
closely resembling it in general, 
