D. POPULATION BIOLOGY 



Populations in the Tendoys range in estimated size from very 

 small with less than 10 plants to very large with over 10,000; 

 most are of intermediate size. There is a tendency for plants 

 to grow in clumps. Plants were flowering in June. 



E. MANAGEMENT CONSIDERATIONS 



This inconspicuous species has turned out to be far more 

 common than older records indicated, fulfilling Lesica and 

 Shelly's (1991) predictions. The species has a wide 

 distribution both rangewide and within Montana. It is often 

 found on loose talus slopes, a habitat that is usually 

 inherently protected from impacts such as grazing and 

 recreational trampling, and is adapted to disturbance. For 

 these reasons, we recommend that this species be dropped from 

 further BLM consideration and from state tracking. 



Pediocactus simpsonii (Engelm.) Britt. & Rose 

 Simpson's hedgehog cactus 



A. DESCRIPTION 



1. General description: This is a small pincushion cactus 

 (Cactaceae) . The stem is spherical and partly buried and 

 bears spines on raised tubercles. The showy pinkish flowers 

 which bloom early in the season are borne on top of the spine 

 bearing tubercles. See slide 13 in Appendix E. 



3. Diagnostic characters: In Montana, the only other 

 pincushions are species of Coryphantha . These two genera are 

 distinguished by the position of attachment of the flowers and 

 fruits. In Coryphantha they are attached at the base of the 

 tubercles, away from the spines, while in Pediocactus they are 

 borne on the tubercles, near the spines. A pocket knife is 

 useful for dissecting the cactus to observe this feature in 

 the field. Vegetatively , these genera are very similar. 

 Species of Coryphantha were never seen in the Tendoys. 



B. GEOGRAPHIC DISTRIBUTION 



1. Species range: "Washington to Wyoming, south to Nevada, 

 Arizona, and New Mexico (Welsh et al. 1987)." Also in 

 southwestern Montana. 



2. Montana distribution: Dorn (1984) lists as reported from 

 southwestern Montana, but the occurrence was verified in 

 Beaverhead County, from foothills of the Pioneer Mountains in 

 1992. 



3. Occurrences in the study area: Eight populations were 

 documented, scattered throughout the range. 



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