14 



Only a small subpopulation (<100 plants) was found on BLM 

 land. Elsewhere in Montana, the species was considered 

 "common" at one site, but other populations were estimated 

 to consist of fewer than 1,000 individuals or were 

 incompletely surveyed. 



2. Reproductive biology: Reproduction is by seed. Most plants 

 were flowering with a few having early fruits when the 

 population was surveyed (June 21) but there were also many 

 vegetative plants. Browsed heads were observed in 1994. 



E. MANAGEMENT CONSIDERATIONS 



Astragalus terminalis has a relatively narrow range and is 

 considered rare in Wyoming (Fertig 1994) and in parts of its 

 range in Idaho (Barneby 1964). Although Barneby (1964) described 

 Astragalus terminalis as "locally plentiful in the valleys of the 

 Beaverhead River and Red Rock Creek," it is known from relatively 

 few collections with precise location data, from that locale or 

 elsewhere in Montana. It is possible that the species has 

 undergone decline or that it persists mostly on private or other 

 land which has not been surveyed. Nearly all known Montana 

 populations are subject to livestock grazing; however, the 

 effects of grazing on this species are not known. The population 

 near Pipe Organ Rock is threatened by an infestation of sweet 

 clover (possibly seeded) and other weeds which originates from an 

 excavated stockpond and gravel pile on private land. The BLM 

 subpopulation is in more pristine habitat, but is small, and 

 could be threatened if the weeds spread. BLM Sensitive status is 

 appropriate for this species, rather than the currently proposed 

 Watch status. The occurrences on BLM land probably represent the 

 most defensible remaining populations of this species in Montana, 

 and should be protected from heavy livestock grazing and 

 infestations of exotic plant species. 



Delphinium bicolor Nuttall ssp. novum 

 Limestone Larkspur 



DESCRIPTION 



. . General description: This larkspur, in the Buttercup Family 

 (Ranunculaceae ) , has been identified in the past as 

 Delphinium andersonii or Delphinium geyeri. Herbarium work 

 has shown that Montana plants are not closely aligned with 

 either of these taxa but are more closely related to 

 Delphinium bicolor. A specialist in the genus, Michael 

 Warnock (Sam Houston State University, Huntsville, Texas), 

 was consulted and a new taxon will be described as a 

 subspecies of Delphinium bicolor. The plants are perennials 

 with relatively strong deep roots. The deeply palmately 



