Trees and Shrubs

Yucca aloifolia L.

Frost-tender, slow-growing, rounded shrub or small tree with a simple or branched stem, linear to narrowly lance-shaped, toothed leaves, ending in a stiff point, and, from summer to autumn, stout, erect panicles of pendant, bell-shaped, white, sometimes purple-tinged, flowers held above the foliage.  To 8m.  [RHSE, Hortus]. See also Yucca aloifolia L.f. var. draconis (L.) Voss.

Yucca aloifolia L. var. crenulata

For a description of the species see Yucca aloifolia L. Crenulata is described by Johnson’s Dictionary as a frost-hardy succulent with scalloped leaves and white and green flowers, growing to 60cm [JD]. It is a variety of Y. aloifolia with somewhat scalloped leaves. Haworth gave specific names to a number of naturally occurring forms of Y. aloifolia.

Yucca aloifolia L. var. draconis (L.) Engelm.

For details of the species see Yucca aloifolia L.  The variety draconis has a branched trunk and drooping leaves.  It may be synonymous with Yucca aloifolia pendula listed by Paxton's and Johnson's Dictionary.  [RHSD, Hortus]. 

Yucca bowieana [Macarthur]

Unidentified Yucca or related species. I have found no reference to a plant of this name.

It is possibly an error with Aloe bowieana intended, although it seems unlikely that Macarthur would mistake a plant from the Americas with one from South Africa. See Notes.

Yucca filamentosa L.

Fully-hardy, clump-forming shrub, stemless or nearly so, with basal rosettes of rigid, inversely lance-shaped leaves, margined with curly white threads, and long upright panicles of nodding, bell-shaped white flowers, tinged cream or green, in summer.  To 75cm, flowers to 1.5m.  [RHSE, Hortus]. 

Yucca flaccida Haw. var. glaucescens Trel.

Stemless or short-stemmed yucca with narrow, pointed, green or glaucous leaves, to 90cm, bent down at the end and with the leaf margins furnished with threads, usually straighter than Yucca filamentosa.  The flowers are yellowish white in erect, downy panicles.  [RHSD, Hortus]. 

Yucca glauca Nutt.

Stemless or short-stemmed yucca with a horizontal rosette, to 1.2m across of narrow, pointed, glaucous leaves.  The flowers are greenish-white, pendulous, in an erect raceme to 1.5 m high.  [RHSD, Hortus]. 

Yucca gloriosa L.

Frost-hardy, erect shrub with a stout stem, branching at the top, bearing terminal tufts of narrowly lance-shaped, stiffly-pointed, arching leaves, and, in summer to autumn, long, upright panicles of pendant, bell-shaped, sometimes purple-tinged, white flowers.  To 2m.  [RHSE, Hortus].