YUCCA AND AGAVE. 



The following addition to tlie Catalogue of the plants of Nevada and Utah is from Dk. Geoegb 

 Engelmann as a result of Ms recent study of our hitherto ill-defined and little understood species of 

 these genera. 



YUCCA, L. 



Perianth cup-shaped, of six (whitish) petal-like lanee-oval acutish leaves, withering-persistent, 

 longer than the six cluh-shaped stamens. Stigmas 3, more or leas united. Pod ohlong or cylindrical, 

 somewhat 6-sided, 3-celled, the cells incompletely 2-celled by a partition from the hack. Seeds very 

 numerous, flat, horizontal, in 6 rows, hlack, with the linear straight or curved embryo diagonal, as long 

 as the albumen.— Stems woody, fibrous, very short or rising into thick columnar palm-like simple or 

 branching trunks, bearing persistent rigid linear or lance-linear mostly sharp-pointed leaves, with smooth, 

 rough, or filamentose edges, and terminated by an ample compound panicle (or rarely a spike) of showy 

 pendulous flowers, opening wide in the evening and half-closed in the morning. 



5 1. EU-YUCCA. Filaments club-shaped, obtuse, papillose-pubescent, mostly shorter than the pistil, 



often spreading or recurved ; anthers oblong or sagittate ; ovary prismatic or subcylindric, obtuse 



or narrowed into a sort of style ; stigmas elongated, bi-lobed, papillose. 



* Sarcocarpa. Pendulous fruit fleshy and iudehiscent ; thick seeds somewhat rugose, with deeply lobed 

 (ruminated) albumen. , 



1. Y. BACCATA, Torr. Bot. Mex. Bound. 221. Stems none, or short, or several feet high ; leaves very 

 thick and rigid, lance-linear, narrowed above the broad base, concave, terminating in a stout spine, with 

 very coarse marginal fibres ; flowers panicled ; petals rhombic-ovate (IJ-li' long) or linear-lanceolate, 

 (sometimes over 3' long;) ovary attenuate into a style; stigmas short; _fruit ovate or cylindric, 

 long-rostrate. — From New Mexico and S. Colorado, through S. Utah, to Arizona, California and Mexico. 

 Northward a low plant, it becomes a tree farther south ; leaves 1^-2° long, 1^-2' wide. The edible sweet 

 fruit are often called "Dates;" seeds variable in size, usually the largest in the genus, 5-6" wide, IJ-li" 

 thick. 



* * Clistocarpa. Fruit iudehiscent, at last dry; seeds thickish, smooth, with the albumen entire. 



2. Y. BEEViFOLiA, Eng. (T. Dmconis, Var. arim-escens, Torr. Bot. Wlii-pp., Pac. S. B. Surv. 4. 147.) 

 Tree-like, at last much branched ; the short narrow leaves crowded at the end of the branches, thick 

 very rigid, stout and sharp-pointed, not narrowed above the broad base, serrulate on the margin ; panicle 

 sessile at the end of the branches ; fruit large, 4' long, ovate, pointed.— Deserts of S. Utah, thi-ough 

 Arizona, to S. E. California where it forma entire forests on the desert plateaus at 2-4,000 feet altitude. 

 Often 20-30° high and 1-2° in diameter, with a thick rough bark; leaves 4-6' or in younger specimens 

 10-12' long, i-J' wide, stiff'er and stouter pointed than any other in the genns. The flower when known 

 may make it necessary to remove it from § Euyucca. 



* * * CTuenomrpa. Erect fruit dry, septicidally 3-valved from the apex, the valves at last again 

 divided at tip ; seed very thin, smooth, with an entire albumen. 



3. Y. ANGUSTiFOLiA, Pursh. Stems none or short ; leaves narrowly linear, scarcely narrowed above 

 the broad base, rigid, spiny-pointed, nearly flat above, convex below, with very slender marginal fibres 

 li-2i°long; flowers spiked; petals broad-ovate, li-lf long ; stigmas half as long as the ovary sessile' 

 erect; capsule cylindric-ovate, thick, obtuse, short-pointed; seed large, (5-7" in diameter,) with a wide 

 margin. 



Var. p. EABIOSA, Eng. Stems several feet high ; flowers in large panicles ; petals narrow lanceolate 

 IJ-lf ' long. ' 



Western plains to Texas, Colorado, New Mexico and into Utah ; the variety in Central Arizona and 

 northward to the borders of Utah. A very variable plant, which eastward toward the Mississippi and 

 the Gulf has broader, shorter, and more flaccid leaves, (r. stricta, Sims ?,) but is .always recognized by the 

 thick never constricted obtuse capsule and the large broad-margined seed, 5-7" wide Both forms here 



