[taxon report][distribution map][all photos][line drawing]
Scientific Name: Peritoma multicaulis (de Candolle) H.H. Iltis
Synonyms: Cleome multicaulis de Candolle; Cleome sonorae A. Gray; Peritoma sonorae (A. Gray) Rydberg
Vernacular Name: Slender spiderflower
R-E-D Code: 2-2-1
Description: Annual; stems slender, erect, up to 60 cm tall; leaves sessile or with short stalks, palmately compound, leaflets 3, elliptic, slender, folded, 2 mm wide or less; flowers in axils of stem leaves, petals pink or white, 4-7 mm long; pods elongate, up to 20 mm long and 4 mm wide; smooth, circular in cross section, with a narrow stalk-like base; pods bent abruptly downward at the juncture of the pod's narrow base and the pedicel. Flowers August to September.
Similar Species: The widespread and common Peritoma serrulata (Rocky Mountain bee-plant) has narrowly elliptic leaflets, 5-15 mm wide and flowers 8-13 mm long.
Distribution: New Mexico, Grant and Hidalgo counties; Wyoming, south-central Colorado, southeastern Arizona, western Texas; Mexico.
Habitat: Wet, saline or alkaline soils; often in and around alkali sinks, alkaline meadows, or old lake beds.
Remarks: The slender spiderflower has not been seen in New Mexico since 1851 when two separate collections were made. One collection was made by George Thurber at Las Playas in Hidalgo county. The other collection was made by Charles Wright at "the mouth of the Mimbres River". References to another Wright collection in New Mexico "in the Valley of the Rio Grande, below Doņa Ana" are most likely based on a mix-up in interpretation of early, incomplete, printed labels.
This is a rare, but widespread wetland species. There are several populations in south-central Colorado and in Wyoming where plants can be locally common. It is nearly extirpated from its entire range south of Colorado. It was documented as extant in 2003 in Presidio County, Texas (Poole et al. 2007).
Conservation Considerations: Many wetlands in the southwest have been destroyed and the few remaining continue to be seriously threatened by various human uses. Continued searches are needed for this species in New Mexico.
Important Literature (*Illustration):
Iltis, H. 1958. Studies in the Capparidaceae V. Capparideaceae of New Mexico. Southwestern Naturalist 3:133-144.
Iltis, H.H. 2007. Studies in Cleomaceae V: A new genus and ten new combinations for the Flora of North America. Novon: A Journal for Botanical Nomenclature 17(4):447-451.
*New Mexico Native Plants Protection Advisory Committee. 1984. A handbook of rare and endemic plants of New Mexico. University of New Mexico Press, Albuquerque.
Poole, J.M., W.R. Carr, D.M. Price and J.R. Singhurst. 2007. Rare plants of Texas: A field guide. W.L. Moody Jr. Natural History Series, number 37. Texas A&M University Press, College Station. 656 pp.
Information Compiled By:
Ken Heil, Joey Herring, 1999; last updated, 2011