Yucca campestris McKelvey,
Yuccas of the southwestern United States, (1947): 173 ff., The Arnold Arboretum of Harvard University, Jamaica Plain, Massachusetts, USA.

Type location:
Between Pyote und Wickett, Texas.

Distribution:
Endemic to West Texas near the New Mexico state-border, grows in the Plains in deep sand dunes.

Short description of the species:

Plants acaulescent or with short stems, solitary or in large clumps of several rosettes. Stems from 30 to 100 cm tall. Leaves grass like, narrow, plano-convex 30 to 65 cm long, 6 mm wide at the middle of the leaves, blue green with white to grey margin, with few fine fibers. Flowering stems erect 50 to 150 cm (sometimes up to 200 cm) tall. Inflorescence paniculata, flowers mostly start between the leaves, Flowers; globular 100 to 120 mm long pale green sometimes tinged pink or rose. Capsule; 40 to 50 mm long, 30 to 45 mm in diameter, dry, symmetrical to slightly constricted. Seeds;  thin, shiny, black 10 mm long and wide. Flowers May - June in habitat.

Hardiness:
Not known!  Please report if you are growing this species.

Notes:
Maybe this species is = Yucca glauca x Yucca elata or Yucca baileyi var. intermedia?
Yucca campestris McKelvey (plains yucca) -- Distribution: High Plains, northern Trans Pecos
Comments: Y. elata X Y. constricta hybrid? (Martin & Hutchins, 1981) References: Vines, 1960*

Pictures:
 

Yucca campestris Grown in Alexander Heim's garden in Greece. Copyright 2007 Alexander Heim.

I don't have any photos of this species in habitat, if you have some I may use please let me know.

My own plants:
#1131 Yucca campestris, Texas, Monahans, fh 1179.82, sown 1999.

Reference:
HOCHSTÄTTER, F; (2000), YUCCA (vol. I): 55 (Yucca campestris)
WEBBER, Agric. Monograph U.S.D.A. 17:62-65 (1953) (Yucca campestris as a syn for Yucca glauca x Yucca elata)
The Flora of Texas Consortium Vascular Plants Endemic to Texas
THIEDE, J. (2001) Illustrated handbook of succulent plants vol. 1. (Monocotyledons (Eggli ed.)): 91. (Yucca campestris).