DESCRIPTION 



1. GENERAL NONTECHNICAL DESCRIPTION: Senecio debilis is 

 a rayless composite with dark orange disk flowers. 

 The stem leaves have rounded lobe tips and are lobed 

 about halfway or more to midrib. The plant is 

 located in moist, alkaline meadows along roadsides. 



2. TECHNICAL DESCRIPTION: Senecio debilis is a fibrous- 

 rooted perennial from a short caudex, 1-5 dm. tall, 

 glabrous or lightly f loccose-tomentose when young; 

 leaves are thickish, somewhat succulent , the basal 

 ones petiolate, with entire to more often crenate or 

 lobulate blades; cauline leaves few and reduced, 

 becoming sessile, sublyrate to pinnately divided, 

 with deep, rounded sinuses and narrow, obtuse or 

 rounded lobes; heads several or rather many, discoid, 

 often somewhat orange; involucre 5-7 mm high. 



3. LOCAL FIELD CHARACTERS: Senecio debilis is 

 distinguished by the bright orange rayless flowers 

 and the stem leaves that have rounded lobes. 



GEOGRAPHICAL DISTRIBUTION 



RANGE: Senecio debilis is found from in northern 

 Colorado northwestward through Wyoming to southwestern 

 Montana and adjacent Idaho. 



:. CURRENT SITES: Senecio debilis was found frequently 

 in the alkaline regions of Centennial Valley, 

 especially the western portion. In Montana, it is 

 known from three counties: Beaverhead, Madison and 

 Lewis and Clark. This species was also surveyed this 

 past year in the Tendoy Mountains (Vanderhorst and 

 Lesica, in progress) . 



ASSOCIATED VEGETATION: Senecio debilis occurs in wet 

 alkaline meadows that are dominated by Carex spp. and 

 Deschampsia elonqatum and with the following forbs: 



Polemonium occidentale (western Jacob's ladder) 



Valerian edulis (edible valerian) 



Cirsium scariosum (elk thistle) 



Juncus balticus (baltic rush) 



Spartina pectinata (cordgrass) 



Hordeum brachyantherum (meadow barley) 



Antennaria microphylla (rosy pussy-toes) 



TOPOGRAPHY AND SOILS: Senecio debilis occurs in 

 bottomlands that are derived from alkaline soils. 



