Search Field Guide
Advanced Search
Montana Field Guide

Montana Field Guides

Henderson's Wavewing - Cymopterus hendersonii
Other Names:  Pteryxia hendersonii

Status Under Review

Global Rank: GNR
State Rank: S2?
* (see State Rank Reason below)

Agency Status
USFWS:
USFS:
BLM:
MNPS Threat Rank:
C-value:

External Links






State Rank Reason (see State Rank above)
Cymopterus hendersonii is currently known in Montana from four locations in the Bitterroot Range of Ravalli Co. and one location in the Madison Range, one location in the Gravelly Range and one location in the Ruby Range, all in Madison Co. All known populations are from high elevations.

Cymopterus hendersonii was described from a collection made by Louis Henderson in east-central Idaho in 1895 (Coulter and Rose 1900). Subsequent treatments of the genus have placed similar plants from south-central Montana to Utah and Colorado into C. hendersonii (Mathias and Constance 1944-45, Cronquist 1961). However, Ronald Hartman has determined that the former plants are different from C. hendersonii and should rightly be called C. longilobus. True Cymopterus hendersonii is known from Madison and Ravalli counties in Montana (R. Hartman, personal communication) and east-central Idaho. Cronquist (1961) reported that the Henderson collection was made in Custer Co., but Love (2003) indicates it was from Lemhi Co.
 
General Description
Henderson's waferparsnip is a low, mat-forming perennial herb with a branched root crown covered in old leaf petioles. The petiolate leaves are all basal, 2-9 cm long and twice divided into well-separated, narrow segments. Herbage is glabrous or slightly roughened. The naked stems are 1-8 cm high, lax or erect. Small yellow flowers are born in a compound umbel subtended by 0-7 linear bracts. Each ultimate umbel is subtended by 3-7 narrow bracts, longer than the flowers. Fruits are elliptic, 2.5-5 mm long with 8 thickened, longitudinal wings protruding up to 1 mm above the surface.

Phenology
Flowering occurs in July and August.

Diagnostic Characteristics
Cymopterus nivalis (=C. bipinnatus) has white flowers and more membranous wings on the fruits. Cymopterus longilobus is a larger plant with most stems greater than 8 cm high. Cymopterus terebinthinus has short-hairy herbage.

Species Range
Present
 


Summary of Observations Submitted for Montana
Number of Observations: 6

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

 

(Observations spanning multiple months or years are excluded from time charts)



Habitat
Cymopterus hendersonii occurs in dry talus or skeletal soil of upper slopes and ridge crests at 2620-3000 m (8,600- 9600 ft.) in elevation. Associated vegetation is sparse and dominated by cushion plants. The plant is associated with limestone in Madison Co. and with granite or metamorphic parent material in Ravalli Co.

Ecology
Cymopterus hendersonii is a small plant and occupies habitats with sparse vegetation
suggesting that it is not tolerant of competition.

Ravalli Co. populations all occur in the Selway-Bitterroot Wilderness. The Madison Range population also occurs in a wilderness area. The populations in the Ruby and Gravelly ranges are subject to livestock grazing; however, it is unlikely that these small forbs are palatable, and the sparsely vegetated habitat is probably not frequented by livestock.

References
Login Logout
Citation for data on this website:
Henderson's Wavewing — Cymopterus hendersonii.  Montana Field Guide.  .  Retrieved on , from