LILIACE. SILVA OF NORTH AMERICA. 5 
some of the arborescent species, which are often beset with leaves from the surface of the ground 
upward, are employed to protect dwellings and gardens from the intrusion of cattle. 
Yucca is rarely attacked by insects,’ and is comparatively free from fungal diseases.’ 
Owing to their numerous clusters of beautiful large waxy white flowers and their habit, unfamiliar 
to northern eyes and the people of the Old World, Yuccas have become favorite garden plants, and 
many of the species may now be seen in the pleasure-grounds of the northern states, and of Europe, 
where they grow without protection in the countries bordering the Mediterranean. 
Yuccas can be raised from seeds, which germinate readily and quickly, by cutting off the terminal 
or lateral crowns of leaves and placing them on the surface of the soil of propagating beds, where they 
will soon develop roots, or from pieces of the stolons. 
The generic name is derived from the Carib name of the root of the Cassava.‘ 
Texas, New Mexico, California, Sonora, and Chihuahua, ii. 490.— on other species also. It appears in the form of very numerous 
Rev. Hort. 1886, 508. 
1 In the coast region of the south Atlantic states Yuccas, espe- 
cially Yucca aloifolia, are frequently injured by the larve of Mega- 
thymus Yucce, Walker, which bore into the underground stems and, 
by weakening the trunk and inducing decay, frequently cause the 
prostration of the plant. The presence of the borer can be detected 
by its excrements at the base of the leaves and by chimney-like 
projections formed by the bases of the flower-stalk and of the 
tender partly devoured young leaves, through which they are 
expelled. (See Riley, Trans. St. Louis Acad. iii. 223 [Notes on the 
Yucca Borer]; 8th Ann. Rep. Insects of Missouri, 169.) 
2 The fungi which are known to attack the different species of 
minute spots which have a black border and a paler-colored centre 
and hardly protrude above the surface of the leaf, and is one of 
Ap- 
parently it attacks the living leaves, which it at first disfigures, and 
the imperfect forms as yet unknown in a perfect condition. 
ultimately destroys, and in the case of cultivated Yuccas it might 
become a serious disease. A larger and more striking, although 
less widely distributed fungus, Dothidea Pringlei, Peck, attacks the 
leaves of Yucca aloifolia and Yucca Schottii, forming prominent 
The other fungi which 
attack Yuceas are all small, the most characteristic being Nectria 
hard black tubercles of considerable size. 
depauperata, Cooke, Leptospheria jilamentosa, Ellis & Everhart, 
Phyllachora scapincola, Saccardo, and Anthostomella nigroannulata, 
The most 
widely diffused among them is probably Kellermannia yuccegena, 
Ellis & Everhart, which infests the leaves of Yucca aloifolia, Yucca 
arborescens, Yucca glauca, Yucca filamentosa, and probably occurs 
Saccardo, belonging to the Pyrenomycetes, and the imperfect Cer- 
cospora Yucce, Cooke, and Septoria Yuccce, Saccardo. 
3 Baines, The Garden, xxxiil. 487. 
‘ Parkinson, Theatr. 154, 1624. 
Yucca belong almost exclusively to the Pyrenomycetes. 
CONSPECTUS OF THE ARBORESCENT SPECIES OF THE UNITED STATES. 
Kuyucca. 
anthers cordate, emarginate, glabrous; pollen powdery; ovary sessile or stipitate ; style 3-lobed, 
Filaments clavate, papillose, free from the perigone, spreading or recurved at maturity ; 
short or elongated. 
Sarcoyucca. Panicle usually sessile. Fruit baccate, pendulous, the exocarp thick and succulent ; 
seeds thick ; 
Panicle glabrous or puberulous. 
albumen ruminate. 
Ovary stipitate. Leaves serrulate, slightly concave, smooth, dark green . . . . 1. Y. ALorronia. 
Leaves concave, blue-green, rough on the lower surface . . .. . 2. Y. TRECULEANA. 
Leaves flat, smooth, dark green . . . a ee a ee ee 3. Y. MACROCARPA. 
Leaves concave above the middle, smooth, light yellow-green. . . . 4. Y. MoHAVENSIS. 
Panicle coated with hoary tomentum. 
Leaves concave, smooth, light yellow-green . . a «= = 5. Y. Scuorrmn. 
Clistoyucca. Panicle stalked or sessile, inclosed at first in a ieee seeciaped bud joaned by 
its closely imbricated bracts. Fruit baccate, erect or spreading, the exocarp becoming thin 
and dry at maturity ; seeds thin ; albumen entire. 
Leaves concave above the middle, blue-green, sharply serrate . . . . . . . . 6. Y. ARBORESCENS. 
Leaves thin, flat or concave toward the apex, rough on the lower surface, dull or glau- 
cous green, more or less plicately folded. . . . . 7. Y. GLORIOSA. 
Chenoyucca. Panicle pedunculate. Fruit capsular, erect, septicidally and loculicidally dehis. 
cent; seeds thin, albumen entire. 
Leaves thin and flat, filamentose on the margins, smooth, pale yellow-green . . . . 8. Y. CONSTRICTA. 
