Sensitive Plant Status Reviews 



Lomatium attenuation Evert 



TAPERTIP BISCUITROOT 



Parsley Family (Apiaceae) 



CONSERVATION STATUS 



U.S. Fish and Wildlife Service: None. It was formerly listed as Category 3C (USDI Fish 

 and Wildlife Service 1993), removing it from Category 2 (C2) status. Listing of C2 

 species was officially discontinued by the Service in 1996 (U.S. Fish and Wildlife Service 

 1996). 



Bureau of Land Management: Sensitive (USDI BLM 1996). 



Montana Natural Heritage Program: It is ranked G2 S2, imperiled by rarity globally 

 and in the state. The global rank was recently changed from G3 to G2 (Fertig 1996, 

 Heidel 1996) because it was found to have a more restricted distribution in Wyoming than 

 previously thought (W. Fertig, pers. commun.). 



DESCRIPTION: Tapertip biscuitroot is a low herbaceous perennial growing from an elongated 

 fleshy root. It has short stems which bear one or two finely dissected 3-pinnate leaves which are 

 2-1 1 cm long and ovate in outline with linear to oblanceolate ultimate segments < 1.5 mm wide. 

 The herbage, flower stem, and inflorescence are scaberulous. The inflorescence is a many 

 flowered compound umbel borne on a long peduncle which exceeds the leaves in fmit. The 

 involucre is absent or inconspicuous, and the involucel is absent or consists of 1 -6 narrow, 

 attenuate bracts 1-4 mm long. The umbellets have about 15 small, yellow-petaled flowers with 

 only 2-6 per umbellet developing into fruits. The mature fruits are glabrous, dorsally flattened 

 schizocarps 5-8 mm long and 3-5 mm wide, with low ribs on their faces (adapted from Evert 

 1983). 



In habit, leaf dissection, and fruit characters, Lomatium attenuatum resembles the more common 

 and widespread Lomatium cous. However, the former has inconspicuous, attenuated involucel 

 bracts (hence its specific epithet) while the latter has conspicuous, broadly rounded bracts. Also, 

 Lomatium attenuatum has greater overall scabrosity. It can be distinguished from low growing 

 species of Cymopteris which it resembles by its fruits which have low ribs, rather than prominent 

 wings on their flattened sides. Figure 4 is a line drawing of the species. 



GEOGRAPHICAL DISTRIBUTION 



Global distribution: Lomatium attenuatum is a regional endemic of the Rocky 

 Mountains. It has population centers in northwestern Wyoming and southwestern 

 Montana which are disjunct, separated by the Yellowstone highlands. 



Montana distribution: The species was first discovered in the state in 1993 by Peter 

 Lesica on BLM land in the Tendoy Mountains, Beaverhead County (Vanderhorst and 

 Lesica 1994). Since then additional Beaverhead County populations were found on 



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