Synonyms:
Yucca louisianensis Trelease. in Mo. Bot. Gard. Ann. Rpt. 13:64 (1902) (in part)
Yucca tenuistyla Trelease, in Mo. Bot. Gard. Ann. Rpt. 13:53 (1902) (in part)

Distribution:
Edward's Plateau, South Texas Plains.

Type location:
Without precise locality: "Western Texas".

Distribution:
From Eastern Edward's Plateau Texas, southwards to the Gulf of Mexico, to South West to the Rio Grande, West of the Pecos River, Texas.

Short description of the species:
Plant acaulescent or with short procumbent stems 20 to 40 cm long (occasionally 100 cm!), growing in clumps of 1 to 20 rosettes. Leaves grass-like 20 to 50 cm (Occasionally up to 65 cm long!), 0,8 to 1,5 cm wide, nearly flat or somewhat plano-convex, twisting, pale to dark green. Leaf margin white or green eventually filiferous, with strait or curled fibers. Inflorescens up to 250 cm, paniculate. Panicle 20 to 45 cm above the leaves, 45 to 120 cm tall, with a few (8 to 15) branchlets. Flowers campanulate (bell shaped) 2,5 to 4,5 cm long. Pistil 2,5 to 3,8 cm long. Ovary 0,5 to 0,6  cm thick, slender cylindrical with oblate apices, pale green. Style 0,8 to 1,1 cm long, whitish green to pale green. Fruit 3 to 6,3 cm long, 1,5 to 4,3 cm thick, Oblong-cylindrical, mostly constricted. Seed black, glossy, with broad marginal wing, 0,7 to 0,9 x 0,9 to 1,5  cm. Flowering in May in habitat.

Hardiness:
Yucca constricta is hardy here in Northern Denmark if it's grown in a raised bed, and is protected against winter moisture from October to May.

My own plants:
#334A Yucca constricta Texas Llano, DJF1306, sown 1992.
            Grown in a raised well drained bed, which is protected against winter moisture from October to May.
            It has lots of fibers along the edge of the leaves. Received as Yucca glauca var. constricta
#334B Yucca constricta Texas Llano, DJF1306, sown 1992.
            Grown inside an unheated greenhouse,
            It has lots of fibers along the edge of the leaves. Received as Yucca glauca var. constricta
#334C Yucca constricta Texas Llano, DJF1306, sown 1992.
            Grown in a large pot, that are outside during the summer and inside the unheated greenhouse from October to May.
            It has lots of fibers along the edge of the leaves. Received as Yucca glauca var. constricta
#1130 Yucca constricta Texas Woods Hollow Mts., 1270 m., fh 1179.80 sown 2000.

Pictures:

#334A Yucca constricta Texas Llano, DJF1306.
Grown in a raised well drained bed, and protected against moisture from October to May.
Photo by Benny Moeller Jensen ©1999-2005.

Notes:

Some Authors think that Yucca constricta may be a hybrid of Yucca elata x ?

Reference:
BUCKLEY in Proc.. Phil. Acad. Sci., January, 1862, 8 (1863)
TRELEASE in Rep. Missouri Bot. Gard. 13: 53 (1902)
TRELEASE in Rep. Missouri Bot. Gard. 13: 64 (1902)
WEBBER, J. M. Agric. Monograph U.S.D.A. 17: 53-55 (1953) (Yucca constricta)
The Flora of Texas Consortium Vascular Plants Endemic to Texas (Yucca tenuistyla)