3 i8 



FLORA AND SYLVA. 



gradually tapering; stigmatic lobes short. Fruit 

 very large (as much as 8 inches long), mostly 

 conical-ovoid, with adnate calyx-disk and fila- 

 ment bases. Trinidad, Colorado, and west to 

 southern Nevada. The first discovered of the 

 western fleshy-fruited Yuccas, differing from 

 the species which have been confounded with 

 it in its prostrate caudex, the crowns of which 

 rarely rise much above the earth, its large pen- 

 dent flowers, and its conical large fruit with the 

 base of the perianth adnate as a conspicuous 

 disk, and the bases of the filaments forming 

 fleshy papillae, as in T. aloifolia. The T. baccata 

 of the Pacific coast is what is here called T. 

 Mohavcnsis. 



T. macrocarpa (Torrey). — Arborescent, 

 sub-simple, becoming 10 to 15 feet high. 

 Leaves yellowish green, 1^ to 3 feet long, ii to 

 2 inches wide, usually rough, concave, coarse- 

 ly filiferous. Panicle glabrous or occasionally 

 pubescent, the bracts at first often brownish. 

 Flowers mostly more globose and smaller, the 

 perianth segments usually nearly 2 inches long. 

 Fruit oblong, not so large as in the preceding. 

 Las Cruces, to the Dragoon Pass, Arizona, 

 northern Chihuahua, and vicinity of Presidio. 

 When seen from a distance resembles T. Tre- 

 culeana, though usually of a yellower-green 

 foliage. The trunk very rarely branches, and 

 is usually 6 to 10 feet high, though occasion- 

 ally specimens are seen exceeding 1 5 feet. Its 

 concave stiff leaves are usually 2 or 3 feet long 

 and about 2 inches wide, and, as in T. baccata, 

 they are rough like shagreen on the back, and 

 frequently on both, surfaces, and very coarsely 

 grey filiferous. The fruit varies greatly in form 

 and size. 



T. Mohavensis (Sargent). — With habit and 

 general characters of the preceding. Style very 

 short, contracted. Fruit mostly smaller. West- 

 ern Arizona, southern Nevada, and California. 

 The principal difference between this and the 

 preceding lies in the style, which is contracted 

 and short in the one, and elongated in the other, 

 but the great area of desert country lying be- 

 tween their respective localities makes it de- 

 sirable to class them as distinct species. 



Mr. Trelease concludes with a few inter- 

 esting notes upon the economic uses, and re- 

 productory peculiarities of the Yuccas : — 



" The Yucceas possess very fibrous leaves 

 and local use is made of the fibre almost every- 



where that the plants grow. In the south- 

 eastern United States, and as far as the Indian 

 Territory, the leaves of species of Yucca of 

 the Jilamentosa group, commonly called ' bear- 

 grass,' are much used for such work as making 

 seats for chairs and especially hanging meat, 

 for which they are so much prized in the 

 country that the plants are tolerated as weeds 

 in cultivated fields. In Mexico and our south- 

 western states the fibre of several of the baccate 

 species is crudely cleaned and put to various 

 local uses, cordage included. The long leaves of 

 " palma local" (Y. Treculeana) ,with coarse fibre, 

 and "izote " {T. Schottii Ja/iscensis), with fine 

 fibre, are apparently of considerable use in this 

 manner, respectively in the eastern and western 

 parts of Mexico. 



" The pollination relations of nearly all of 

 the group are among the most peculiar and 

 restricted thus far discovered. I .aloifolia in an 

 exceptional way appears to be freely self-fertile, 

 but self-seeding is very unusual with all of the 

 other species of this genus. These, so far as is 

 known, depend for their pollination upon 

 small moths belonging to thetineid genus Pro- 

 nuba. These moths are not known to feed in 

 the larval stage on anything but the developing 

 seeds of the plants named; so that the mutual 

 dependence of moth upon plant and of plant 

 upon moth appears to be absolute. The rainfall, 

 which stimulates the flowering of the Yuccas, 



1 invariably induces the appearance of these 

 grubs, even though they may have been absent 



I through several dry seasons. The bearing and 

 meaning of this fact has as yet escaped both 

 botanists and entomologists. That the flowers 

 were formerly pollinated otherwise appears 

 certain from the presence of nectar-glands 

 which now appear to be useless." 



From this genus, as now limited by Pro- 

 fessor Trelease, are separated the beautiful T. 

 Whippleioi California, which is frequently cul- 



| tivated in Europe — this is placed in the genus 

 Hesperoyucca ; the large "Joshua-tree" of the 

 Mohare Desert — T. brevifolia of Engelmann, 

 which is now called Clistoyucca arborescens; 

 and, perhaps the most beautiful of all the 

 Yucca-like plants, a tree from the mountains 

 below Saltillo, Mexico, with large Tube- 

 rose-like flowers, which is made the type of 

 a new group Samuela, under the name of S. 

 Carnerosana. 



