1. YUCCA L.
Trees with simple or branched stems prolonged by axillary naked buds, dark thick corky bark, light fibrous wood in concentric layers, and large stout horizontal roots; or often stemless. Leaves involute in the bud, at first erect, usually becoming reflexed, abruptly narrowed above the broad thickened clasping base, usually widest near the middle, concave on the upper surface, involute toward the horny usually sharp-pointed apex, convex and often slightly keeled toward the base on the lower surface, the margins serrulate or filamentose, light or dull green. Flowers fertilized by insects and opening for a single night, on slender pedicels in 2 or 3-flowered clusters or singly at the base of the large compound panicle furnished with conspicuous leathery white or slightly colored bracts, those at the base of the pedicels thin and scarious; perianth cup-shaped, with thick ovate-lanceolate creamy white segments more or less united at base, usually furnished with small tufts of white hairs at the apex, those of the outer rank narrower, shorter, and more colored than the more delicate petal-like segments of the inner rank; stamens 6, in 2 series, free, shorter than the ovary (as long in 1), white, with club-shaped fleshy filaments, obtuse and slightly 3-lobed at the apex, and cordate emarginate anthers attached on the back, the cells opening longitudinally, curling backward and expelling the large globose powdery pollen-grains; ovary oblong, 6-sided, sessile or stalked, with nectar-glands within the partitions, dull greenish white, 3-celled, gradually narrowed into a short or elongated 3-lobed ivory-white style forming a triangular stigmatic tube. Fruit oblong or oval, more or less distinctly 6-angled, 6-celled, usually beaked at the apex, baccate and indehiscent or capsular and 3-valved, the valves finally separating at the apex; pericarp of 2 coats, the outer at maturity thick, succulent and juicy, thin, dry and leathery, or thin and woody. Seeds compressed, triangular, obovoid, or obliquely ovoid or orbicular, thick, with a narrow 2-edged rim, or thin, with a wide or narrow brittle margin; seed-coat thin, black, slightly rugose or smooth; embryo in plain or rarely ruminate hard farinaceous oily albumen; cotyledon much longer than the short radicle turned toward the small oblong white hilum.
Yucca is confined to the New World and is distributed from Bermuda and the eastern Antilles, through the south Atlantic and Gulf states to Oklahoma and Arkansas, and through New Mexico and northward along the eastern base of the Rocky Mountains to South Dakota, westward to middle California, and southward through Arizona, Mexico, and Lower California to Central America. About thirty species with many varieties and probable hybrids are recognized. Of the species which inhabit the territory of the United States nine assume the habit and attain the size of small trees. The root-stalks of Yucca are used as a substitute for soap, and ropes, baskets, and mats are made from the tough fibres of the leaves. Many of the species are cultivated, especially in countries of scanty rainfall, for their great clusters of beautiful flowers, or in hedges to protect gardens from cattle.
The generic name is from the Carib name of the root of the Cassava.
CONSPECTUS OF THE ARBORESCENT SPECIES OF THE UNITED STATES.
Flower-clusters usually sessile, or short-stalked. Fruit pendulous, with thick succulent flesh; seeds thick; albumen ruminate. Segments of the perianth slightly united at the base. Panicle glabrous or puberulous. Ovary stipitate; leaves sharply toothed on their horny margins, smooth, dark green, slightly concave.1. [Y. aloifolia] (C). Ovary sessile. Leaves concave, blue-green, rough on the lower surface.2. [Y. Treculeana] (E). Leaves concave above the middle, light yellow-green, smooth. Style elongated.3. [Y. macrocarpa] (E, H). Style short.4. [Y. mohavensis] (G, H). Panicle coated with hoary tomentum; leaves concave, smooth, light yellow-green.5. [Y. Schottii] (H). Segments of the perianth united below into a narrow tube; leaves flat, smooth, dark green.6. [Y. Faxoniana] (E). Fruit erect or spreading, the flesh becoming thin and dry at maturity; seeds thin; albumen entire. Leaves rigid, concave above the middle, blue-green, sharply serrate.7. [Y. brevifolia] (F, G). Leaves thin, flat or concave toward the apex, nearly entire, rough on the lower surface, dull or glaucous green.8. [Y. gloriosa] (C). Flower-clusters long-stalked; fruit capsular, erect, finally splitting between the carpels and through their backs at the apex; seeds thin; albumen entire; leaves thin, flat, filamentose on the margins, smooth, pale yellow-green.9. [Y. elata] (E, H).
1. [Yucca aloifolia] L. Spanish Bayonet.
Leaves 18′—32′ long, 1¼′—2½′ wide, erect, rigid, conspicuously narrowed above the light green base, widest above the middle, slightly concave on the upper surface, smooth, dark rich green, with a stiff dark red-brown tip, and horny finely and irregularly serrate margins; long-persistent. Flowers from June until August on stout pedicels, in nearly sessile glabrous or slightly pubescent panicles 18′—24′ long; perianth 1′—1½′ in length and 3′ or 4′ across when fully expanded, the segments ovate, thick and tumid toward the base, those of the outer rank rounded and often marked with purple at apex, the inner acuminate and short-pointed; stamens as long or sometimes a little longer than the light green ovary raised on a short stout stipe. Fruit ripening from August to October, elongated, ellipsoidal, hexagonal, 3′—4′ long, 1¼′—1½′ thick, light green when fully grown, and in ripening turning dark purple, the outer and inner coats forming a thick succulent mass of bitter-sweet juicy flesh, finally becoming black and drying on its stalk; seeds ¼′—⅓′ wide, about 1/16′ thick, with a thin narrow ring-like border to the rim.
A tree, occasionally 25° high, usually much smaller, with an erect or more or less inclining simple or branched trunk slightly swollen at base, and rarely more than 6′ in diameter; sometimes with numerous clustered stems. Bark near the base of the trunk thick, rough, dark brown, marked above by scars left by falling leaves.
Distribution. Sand dunes of the coast from North Carolina to eastern Louisiana; west of the Apalachicola River attaining its largest size and sometimes ranging inland through Pine-forests for thirty or forty miles; and in Yucatan (var. yucatana Trel.).
A common garden plant in all countries with a temperate climate, and long naturalized in the southern states far beyond the limits of its natural range, in some of the West Indian islands and on the Gulf coast of Mexico. Forms with leaves variously striped with white, yellow, and red or with recurving leaves are frequent in cultivation.
2. [Yucca Treculeana] Carr. Spanish Bayonet. Spanish Dagger.
Leaves 2½°—4° long, 2′—3¼′ wide, slightly or not at all contracted above the dark red lustrous base, concave, stiff, rigid, dark blue-green, rough on the lower surface, nearly smooth on the upper, with a short stout dark red-brown tip, and dark brown margins roughened by minute deciduous teeth and ultimately separating into slender dark fibres; persistent for many years, the dead leaves hanging closely appressed against the trunk below the terminal crown of closely imbricated living leaves. Flowers in March and April on slender pedicels, in dense many-flowered glabrous or puberulous panicles 2°—4° long and raised on short stout stalks; perianth 1′—2′ long, 2′—4′ in diameter when fully expanded, with narrow elongated ovate-lanceolate to ovate segments, ¼′ wide, acute, thin and delicate, furnished at apex with a conspicuous tuft of short pale hairs; filaments slightly papillose, about as long as the prismatic ovary gradually narrowed above and crowned by the deeply divided stigmatic lobes. Fruit ripening in the summer, 3′—4′ long, about 1′ thick, dark reddish brown or ultimately black, with thin succulent sweetish flesh; seeds about ⅛′ wide, nearly 1/16′ thick, with a narrow border to the rim.
A tree, occasionally 25°—30° high, with a trunk sometimes 2° in diameter and numerous stout wide-spreading branches; usually smaller and often forming broad low thickets 4°—5° tall. Bark on old trunks ¼′—½′ thick, dark red-brown and broken into thin oblong plates covered by small irregular closely appressed scales. Wood light brown, fibrous, spongy, heavy, difficult to cut and work.
Distribution. Shores of Matagorda Bay, southward through western Texas into Nuovo Leon, and through the valley of the Rio Grande to the eastern base of the mountains of western Texas; forming open stunted forests on the coast dunes at the mouth of the Rio Grande; farther from the coast often spreading into great impenetrable thickets.
Cultivated as an ornamental plant in the gardens of central and western Texas and in other southern States, and occasionally in those of southern Europe.
3. [Yucca macrocarpa] Coville. Spanish Dagger.
Leaves 1½°—2° long, 1′—2′ wide, gradually narrowed from the dark red lustrous base to above the middle, rigid, concave, yellow-green, rough on the lower surface and frequently also on the upper surface, with a stout elongated dark tip, and thickened margins separated into stout gray filaments. Flowers in March and April in densely flowered sessile or short-stalked glabrous or occasionally pubescent panicles; perianth usually about 2′ long, with acuminate segments, those of the outer and inner rows nearly of the same size; stamens shorter than the elongated style. Fruit 3′—4′ long, about 1½′ thick, abruptly contracted at apex into a stout point, nearly black when fully ripe, with sweet succulent flesh; seeds about ⅓′ wide, ⅛′ thick, with a narrow border to the rim.
A tree, rarely exceeding 15° in height, with a usually simple stem 6′—8′ in diameter, and often clothed to the ground with living leaves. Bark dark brown and scaly.
Distribution. Arid plains from western Texas to eastern Arizona and southward in Chihuahua.
4. [Yucca mohavensis] Sarg. Spanish Dagger.
Leaves 18′—20′ long, about 1½′ wide, abruptly contracted above the dark red lustrous base, gradually narrowed upward to above the middle, thin and concave except toward the slightly thickened base of the blade, dark green, smooth on both surfaces, with a stout rigid sharp-pointed tip, and entire bright red-brown margins soon separating into numerous pale filaments. Flowers from March to May on slender erect ultimately drooping pedicels 1′—1½′ long, in densely flowered sessile or short-stemmed panicles 12′—18′ in length; perianth 1′—2′ long, the segments united at the base into a short tube, thickened and hood-shaped at the apex, those of the outer rank often deeply flushed with purple, but little longer than the less prominently ribbed usually wider and thinner segments of the inner rank; stamens with more or less pilose filaments nearly as long as the short style. Fruit ripening in August and September, 3′—4′ long, about 1½′ thick, usually much constricted near the middle, abruptly contracted at apex into a short stout point, dark dull brown or nearly black, with flesh often nearly ½′ thick; seeds ⅓′ wide, rather less than ⅛′ thick, with a narrow border to the rim.
A tree, rarely exceeding 15° in height, with a trunk usually simple or occasionally furnished with short spreading branches, and 6′—8′ in diameter, usually surrounded by a cluster of shorter more or less spreading stems and often clothed to the ground with living leaves. Bark dark brown and scaly. Wood soft, spongy, light brown.
Distribution. Southern Nevada and northwestern Arizona across the Mohave Desert to the California coast, extending northward to the neighborhood of Monterey, California, and southward into northern Lower California; common and attaining its largest size on the Mohave Desert, and sometimes ascending arid mountain slopes to altitudes of 4000° above the sea.
5. [Yucca Schottii] Engelm. Spanish Dagger.
Leaves 2½°—3° long, about 1½′ wide, gradually narrowed upward from the comparatively thin lustrous red base to above the middle, flat except toward the apex, smooth, light yellow-green, with a long rigid sharp light red tip, and thick entire red-brown margins finally separating into short thin brittle threads. Flowers from July to September in erect stalked tomentose panicles; perianth 1′—1¾′ long, the broad oval or oblong-obovate thin segments pubescent on the outer surface toward the base and furnished at the apex with conspicuous clusters of white tomentum; stamens about two thirds as long as the ovary, with filaments pilose at the base, and only slightly enlarged at the apex. Fruit ripening in October and November, obscurely angled, 3½′—4′ long, about 1¼′ thick, often narrowed above the middle, with a stout thick point, and thin succulent flesh; seeds ¼′ wide, about ⅛′ thick, with a thin conspicuous marginal rim.
A tree, in Arizona rarely 18°—20° high, with a trunk often crooked or slightly inclining and simple or furnished with 2 or 3 short erect branches, covered below with dark brown scaly bark, roughened for many years by persistent scars of fallen leaves, and clothed above by the pendant dead leaves of many seasons.
Distribution. Dry slopes of the mountain ranges of Arizona near the Mexican boundary usually at altitudes between 5000° and 6000°, and southward into Sonora.
6. [Yucca Faxoniana] Sarg. Spanish Dagger.
Leaves 2½°—4° long, 2½′—3′ wide, abruptly contracted above the conspicuously thickened lustrous base, widest above the middle, flat on the upper surface, thickened and rounded on the lower surface toward the base, rigid, smooth and clear dark green, with a short stout dark tip, and brown entire margins breaking into numerous stout gray or brown fibres short and spreading near the apex of the leaf, longer, more remote, and forming a thick cobweb-like mass at their base. Flowers appearing in April on thin drooping pedicels, in dense many-flowered glabrous panicles 3°—4° long, with elongated pendulous branches; perianth 2½′ long, the segments thin, concave, widest above the middle, narrowed at the ends, united at base into a short tube, those of the outer rank being about half as wide as those of the inner rank and two thirds as long; stamens much shorter than the ovary, with slender filaments pilose above the middle and abruptly dilated at apex; ovary conspicuously ridged, light yellow marked with large pale raised lenticels, and gradually narrowed into an elongated slender style. Fruit ripening in early summer, slightly or not at all angled, abruptly contracted at apex into a long or short hooked beak, 3′—4′ long, 1′—1½′ thick, light orange-colored and lustrous when first ripe, becoming nearly black, with thick succulent bitter-sweet flesh; seeds ¼′ long, about ⅛′ thick, with a narrow nearly obsolete margin to the rim.
A tree, often 40° high, with a trunk sometimes 2° in diameter above the broad abruptly enlarged base, unbranched or divided into several short branches, and covered above by a thick thatch of the pendant dead leaves of many seasons; frequently smaller and until ten or twelve years old clothed from the ground with erect living leaves. Bark near the base of old trees dark reddish brown, ⅓′—½′ thick, broken on the surface into small thin loose scales.
Distribution. Common on the high desert plateau of southwestern Texas.
7. [Yucca brevifolia] Engelm. Joshua Tree.
Yucca arborescens Trel.
Leaves 5′—8′ or on young plants rarely 10′—12′ long, ¼′—½′ wide, rigid, crowded in dense clusters, lanceolate, gradually tapering from the bright red-brown lustrous base, bluish green and glaucous, smooth or slightly roughened, concave above the middle, with a sharp dark brown tip, and thin yellow margins armed with sharp minute teeth; persistent for many years. Flowers appearing from March until the beginning of May, the creamy white closely imbricated bracts of the nearly sessile pubescent panicle forming before its appearance a conspicuous cone-like bud 8′ or 10′ long; perianth globose to oblong, 1′—2′ long, greenish white, waxy, dull or lustrous, its segments slightly united at the base, keeled on the back, thin below the middle, gradually thickened upward into the concave incurved rounded tip, those of the outer rank rather broader, thicker, and more prominently keeled than those of the inner rank, glabrous or pubescent; stamens about half as long as the ovary, with filaments villose-papillate from the base; ovary conic, 3-lobed above the middle, bright green, with narrow slightly developed septal nectar-glands, and a sessile nearly equally 6-lobed stigma. Fruit ripening in May or June, spreading or more or less pendant at maturity, oblong-ovoid, acute, slightly 3-angled, 2′—4′ long, 1½′—2′ thick, light red or yellow-brown, the outer coat becoming dry and spongy at maturity; seeds nearly ½′ long, rather less than 1/16′ thick, with a broad well-developed margin to the rim, and a large conspicuous hilum.
A tree, 30°—40° high, with a trunk 2°—3° in diameter, rising abruptly from a broad thick basal disk, thick tough roots descending deeply into the soil, and stout branches spreading into a broad, often symmetrical head formed by the continued forking of the branches at the base of the terminal flower-clusters; the stem until 8°—10° high simple and clothed to the ground with leaves erect until after the appearance of the first flowers, then spreading at right angles and finally becoming reflexed. Bark 1′—1½′ thick, deeply divided into oblong plates frequently 2° long. Wood light, soft, spongy, difficult to work, light brown or nearly white; sometimes cut into thin layers and used as wrapping material or manufactured into boxes and other small articles. The seeds are gathered and eaten by Indians.
Distribution. Southwestern Utah to the western and northern rim of the Mohave Desert in California; most abundant and of its largest size on the foothills on the desert slope of the Tehachapi Mountains, California.
8. [Yucca gloriosa] L. Spanish Dagger.
Leaves 2°—2½° long, gradually narrowed above the broad base and then gradually broadened to above the middle, thin, flat or slightly concave toward the apex, frequently longitudinally folded, dull often glaucous green, roughened on the under surface especially above the middle, with a stout dark red tip, and pale margins serrulate toward the base of the leaf, with minute early deciduous teeth, or occasionally separating into thin fibres. Flowers in October, in pubescent or glabrate panicles, 2°—4° long, on stout stalks sometimes 3°—4° in length, their large creamy white bracts forming before the panicle emerges a conspicuous egg-shaped bud 4′—6′ long; perianth when fully expanded 3½′—4′ across, its segments thin, ovate, acute, or lance-ovate, often tinged with green or purple, slightly united at the base, pubescent at apex; stamens about as long as the ovary, with hispid or slightly papillose filaments and deeply emarginate anthers; ovary slightly lobed, 6-sided, light green, gradually narrowed into the elongated spreading stigmatic lobes. Fruit very rarely produced, prominently 6-ridged, pendulous, 3′ long, 1′ in diameter, cuspidate, raised on a short stout stipe, with a thin leathery almost black outer coat; seeds ¼′ wide and about 1/36′ thick, with a smooth coat and a narrow marginal rim.
A tree, with a trunk occasionally 6°—8° high and 4′—6′ in diameter, simple or rarely furnished with a few short branches and usually clothed to the base with pendant dead leaves; in cultivation often becoming much larger, with a stout trunk covered with smooth light gray bark, and erect or in one form (var. recurvifolia Engelm.) pendulous leaves.
Distribution. Sand dunes and the borders of beaches of the seacoast from North Carolina to northern Florida.
Often cultivated with many forms in the gardens and pleasure-grounds of all temperate countries.
9. [Yucca elata] Engelm. Spanish Dagger.
1. Yucca radiosa Trel.
Leaves 20′—30′ long, ¼′—½′ wide, rigid, gradually narrowed from the thin base, tapering toward the apex, or sometimes somewhat broadest at the middle, thin, flat on the upper surface, slightly thickened and rounded on the lower surface toward the base, smooth, pale yellow-green, with a slender stiff red-brown tip, and thickened entire pale margins soon splitting into long slender filaments. Flowers in May and June on slender spreading more or less recurved pedicels, in glabrous much-branched panicles 4°—6° long, raised on stout naked stem 3°—7° in length; perianth ovoid and acute in the bud, when fully expanded 3½′—4′ across, its segments united at the base into a short slender distinct tube, ovate or slightly obovate, those of the outer rank usually acute, not more than half as broad as those of the inner rank; stamens as long or a little longer than the ovary, with slender nearly terete filaments; ovary sessile, almost terete, pale green, abruptly contracted into the stout elongated style. Fruit an erect oblong capsule rounded and obtuse at the ends, tipped by a short stout mucro, conspicuously 3-ribbed, with rounded ridges on the back of the carpels, 1½′—2′ long, 1′—1½′ wide, with a thin firm light brown ligneous outer coat closely adherent to the lustrous light yellow inner coat, in ripening splitting from the top to the bottom between the carpels, and through their backs at the apex; seeds ⅓′ wide and about 1/32′ thick, with a smooth coat and a thin brittle wide margin to the rim.
A tree, with a rough much-branched underground stem penetrating deep into the soil and a trunk often 15°—20° high and 7′—8′ in diameter, covered above with a thick thatch of the pendant dead leaves of many years, simple, or branched at the top with a few short stout branches densely covered with leaves at first erect, then spreading nearly at right angles, and finally pendulous. Bark dark brown, irregularly fissured, broken into thin plates, about ¼′ thick. Wood light, soft, spongy, pale brown or yellow.
Distribution. High desert plateaus from southwestern Texas to southern Arizona; southward into northern Mexico; most abundant and of its largest size on the eastern slope of the continental divide in southern New Mexico and along the northern rim of the Tucson Desert in Arizona.