Yucca harrimaniae var. neomexicana (Woot. & Standl.) Reveal


Family: Agavaceae

Vernacular Name: New Mexico Spanish bayonet

Synonym: Yucca neomexicana Woot. & Standl.

Distribution: This Yucca is documented from a relatively small area in sw. Baca and Las Animas counties Colorado, the western tip of Cimarron County, Oklahoma, and Colfax and Union counties, New Mexico. I have not seen it in adjacent counties, but it is rumored from near Walsenburg, Huerfano County, Colorado, and from Harding, Mora, and San Miguel counties in New Mexico. It could be in extreme nw. Dallam County, Texas if any habitat laps over the state line.

In no place have I found Y. neomexicana approaching the foothills of the Sangre de Cristos. It seems totally restricted to the lava-capped mesa country of the Plains near the southern Colorado state line.

Habitat: Y. neomexicana is moderately restricted in habitat. I have seen it only on escarpments and rock outcroppings. I do not know the geology, but believe the preferred rock type to be a dense laminated sandstone with some properties of shale. The plant also grows on basalt, and perhaps other rocks.

Remarks: Yucca glauca and Y. neomexicana have been rumored to hybridize, but I believe this assumption is due to more confusion of the observer than to fact. Most Yucca species will make occasional hybrids when growing microsympatrically, but I have been unable to find suspect plants involving Y. neomexicana as of yet.

S.D. McKelvey (1947) reported Y. neomexicana from the area of La Veta in Huerfano County, Colorado. This is close to the main distribution, but it is in a mountainous area to the west, and I have been unable thus far to find it there (only finding Y. glauca/baileyi). However, I have yet not seen her herbarium specimens, so cannot be positive that it does not occur there.

All of J.M. Webber's (1953) and McKelvey's records for the Pacific Slope of the Rockies are referable to Yucca harrimaniae, which is related, but clearly distinct (though perhaps not at the species level, an opinion open to debate and in need of study).

As it is, I believe the plant may qualify for recognition on our list. It is not rare, but it seems quite restricted in range.

Plants Seen or Cited: Yucca neomexicana Wooton & Standley 1913. Contr. U.S. Natl. Herb. 16: 115. T.L. Volcanic hill about half a mile north of Des Moines, Union County, New Mexico. (=Y. coloma) D.M. Andrews. 1926. Rockmont Nursery, Autumn Catalogue, p. 22. (epithet is short for Colorado-Oklahoma)

Information Compiled By: David J. Ferguson