Yucca glauca Nutt.
Synonyms: Y. angustifolia Pursh
An evergreen shrub with a low, often prostrate stem carrying a hemispherical head of leaves 3 to 4 ft across. Leaves narrow linear, 1 to 21⁄2 ft long, 1⁄2 to 3⁄4 in. wide, tapering to a long fine point, of a glaucous green, the margins white, and beset with a few threads. Raceme, erect, 3 to 41⁄2 ft high, rarely branched. Flower dull greenish white, 21⁄2 to 3 in. long, pendulous. Bot. Mag., t. 2236.
Native of the western central USA from Texas and New Mexico north to Kansas, Nebraska and southern Wyoming; it was discovered by Thomas Nuttall, and introduced by him in 1811, when he visited England, bringing with him specimens, seeds and bulbs of some of the plants he had found during his journey from the Great Lakes to the Missouri and then south to New Orleans. His description was published in 1813 in a catalogue of Fraser’s nursery.
Y. glauca is quite hardy at Kew and Edinburgh, but does not flower with the freedom and regularity of Y. gloriosa and Y. recurvifolia. Neither is it so striking, being of a pale green, rather than truly white. Still, it is quite handsome.
var. stricta (Sims) Trel. Y. stricta Sims sec. Trel.; Y. glauca var. gurneyi McKelvey – A robust variety with a more branched inflorescence, described from plants collected by James Gurney in Seward County, Kansas, and brought into cultivation in the Missouri Botanic Garden. Trelease identified this variety with the yucca named Y. stricta in Bot. Mag., t. 2222 (1821). This was said to have been raised from seeds sent by John Lyon in 1816 from the Carolinas, where Y. glauca does not occur. Either Lyon obtained the seeds from a collector who had visited the area of Y. glauca, or Sims was mistaken and the plant had in fact been raised from the seeds of Y. glauca brought to England by Nuttall.
Y. × karlsruhensis Graebener – A hybrid of Y. glauca (seed-parent), raised by Graebener, head gardener to the Archduke of Baden at Karlsruhe and described in 1903. Y. filamentosa was stated to be the other parent, but the rather lax foliage suggests that it may have been Y. flaccida. It is little known in this country, but is valued in Germany and Central Europe. According to the original description the leaves are glaucous, about 5⁄8 in. wide; flowers white with a reddish stain on the outside. For an illustrated note on this hybrid by Camillo Schneider, see New Fl. and Sylv., Vol. 1 (1928), p. 34 and fig. x.
A cross between Y. glauca (seed-parent) and Y. filamentosa was made by Thomas Javit at St Etienne, France, in 1921. The plants first flowered with him in 1927 and two years later in the Vilmorin nurseries at Verrières, to which he had given some of the seed. A merit of this cross was that the inflorescences were almost as wide as in Y. filamentosa, but produced earlier (Gard. Chron., Vol. 87 (1934), p. 66 and fig. 27).
Y. angustissima Engelm. ex Trel. – Near to Y. glauca but with more slender leaves, up to barely 1⁄4 in. wide. The flower-spike is racemose as in that species, but shorter. Flowers white, with a pale green or white, oblong style (dark green and swollen in Y. glauca). Native of the southwestern USA, common in northwestern Arizona. It is hardy.