Phlox andicola Nuttall ex A. Gray 



PLAINS PHLOX 



Phlox Family (Polemoniaceae) 



CONSERVATION STATUS 



U. S. Fish and Wildlife Service: None 



Bureau of Land Management: Watch 



Montana Natural Heritage Program: G4 S 1 ; apparently secure globally, but may be 

 critically imperiled in Montana where it is extremely rare. Results of 1997 studies provided a 

 basis for changing the state rank. 



DESCRIPTION: Plains phlox is a perennial herb with loose tufted stems that are 4-10 cm (1-4 in) 

 high, sometimes forming mats, and arising from creeping rhizomes. The 5-8 pairs of opposite, linear 

 leaves have prominent midveins, whitish bases and are 10-25 mm long, ca. 1 mm wide, and come to 

 a sharp point. Foliage is glabrous to sparsely hairy and the stem is distinctly white. The 1-5 flowers 

 are white to pale pinkish or blueish, with a tubular corolla 12-15 mm long, and 5 spreading, well- 

 rounded lobes, 6-9 mm long. The loose inflorescence is borne at the stem tips. There are usually 5 

 stamens and a single style, which is 5-9 mm long, with a 3-lobed stigma. The calyx is 6-1 1 mm long, 

 tubular with 5 herbaceous, hairy, pointed lobes (costae) which are separated by whitish membranes, 

 and with a tangle of pubescence along the lobes. The calyx is shorter than the corolla. Flowering in 

 May-early June. 



Alyssum-leaved phlox (Phlox alyssifolia) has 2-5 mm wide, more elliptic leaves. Hood's phlox 

 {Phlox hoodii) has usually shorter leaves (less than 1 mm long) and, on the average, narrower 

 leaves and smaller corolla tube and calyx. The latter also has calyx length about equaling the corolla 

 tube length. Dimensions of the largest P. hoodii specimens may overlap with those of the smallest P. 

 andicola specimens. Flowering material is needed for definitive identification. 



GEOGRAPHICAL DISTRIBUTION 



Global distribution: Great Plains; from 

 southwest North Dakota to southeast 

 Montana, south to northwest Kansas and 

 eastern Colorado (Great Plains Flora 

 Association 1986). 



Montana distribution: Plains phlox 



has been collected from six locations in 



Carter, Dawson, Rosebud and Sheridan 



counties. It is reported from Wibaux Co. 



in Lesica and Shelly (1991) but a voucher specimen has not been located. 



98 



