Ipomoea tenuiloba Torr.
Distribution: New Mexico, Eddy, Grant, and Hidalgo counties (Austin 1990), also Otero County (see below); Arizona, Cochise (several locations in different mountain ranges), Pima, and Santa Cruz counties (Austin 1991, 1992); Texas, Jeff Davis County (Austin 1992), Trans-Pecos mountains (Correll & Johnston 1979); Mexico, Chihuahua (Austin 1992).
Habitat: Chaparral, Madrean oak woodlands, and ponderosa pine zones [in Arizona] (Austin 1991); slopes and summits (Correll & Johnston 1979).
Plants Seen or Cited: Apparently not in the New Mexico Natural Heritage Program Database. Four collections at UNM from New Mexico:
1. Wagner & Sabo. No. 3444. 9 August 1977. Grant county. Black Range, canyon bottom.
2. Wagner & Sabo. No. 3433. 10 August 1977. Grant county. Slope above Kneeling Nun vista, granite, very rocky.
3. Sivinski. No. 1551. 8 August 1990. Otero county. Sacramento Mountains, Ysletano Canyon, on limestone soil, west-facing slope.
4. Ivey. No. 205. 15 September 1990. 7000 ft. Hidalgo county. Animas Mountains in Gray Ranch. T31S, R18W.
Comments: Austin recognizes two varieties: var. tenuiloba (white flowered) and lemmonii (Gray) Yatskievych & Mason (purple flowered), both of which occur in Arizona and New Mexico.
Discussion: Austin (1992) considers this taxon to be globally rare. Its status is similar in some ways to Draba standleyi (except it does not appear to require an unusual substrate) and Euphorbia bifurcata in that the plants occur in several ranges between west Texas and southern Arizona (and into Mexico), but they are not especially common at any location. D. standleyi was recommended to be on L2, E. bifurcata on L4. This plant seems to be widespread enough to be placed on L4.
Recommendation: Place on L4 (Apparently uncommon in New Mexico, but common elsewhere).
Austin, D.F. 1990. Annotated checklist of New Mexican Convolvulaceae. Sida 14(2):273-286.
Austin, D.F. 1991. Annotated checklist of Arizona Convolvulaceae. Sida 14(3):443-457.
Austin, D.F. 1992. Rare Convolvulaceae in the Southwestern United States. Ann. Missouri Bot. Gard., 1992, 79:8-16.
Correll, D.S. and M.C. Johnston. 1979. Manual of the vascular plants of Texas, second printing. The University of Texas at Dallas, Richardson, TX.
Yatskievych, G. and C.T. Mason, Jr. 1984. A taxonomic study of Ipomoea tenuiloba Torrey (Convolvulaceae), with notes on related species. Madroño 31(2):102-108.
Information Compiled By: David L. Bleakly, 1998