CONTRIBUTIONS TO THE BOTANY OF MICHIGAN. 207 



leaves, glabrous and shining above and purplish beneath; elliptical or 

 oval-lanceolate, an inch or less wide by four or five long and acutish at 

 both ends, floating. Spike ovate. This may be considered the type. 

 Floating in shallow water, Keweenaw county. Not common. The other 

 form is a coarsely branched plant with stems often ten or twelve feet 

 long and with long-petioled, mainl}^ cordate-ovate leaves and a cylin- 

 drical spike. It may be known as Pohgonum amphibium L. var. coc- 

 eineum (Muhl) (P. coccincum Muhl. in Willd. Enum. 1,428, 1809). P. 

 incarnatum Ell. is frequent in KeweeuaAV county and also on Belle Isle. 

 P. hydropiperoides Six. var. Macounii Small is frequent at Orion, Mich. 



Chenopodiacca\ 



Atriplex hastata Lin. is common at Detroit and Ypsilanti ; it has 

 triangular halberd-shaped leaves ; erect or diffusely spreading. 



Var. patula (Lin.) A. patula Lin. Sp. PI. 1053, 1753.) This form 

 is intermediate between the species and the following variety ; the leaves 

 are lanceolate-hastate or with a short lobe on each side near the base; 

 prostrate. Common at Detroit. 



Var. littoralis {Lin.) {A. littoralis Lin. 1. c. 1051). Erect with linear- 

 lanceolate, entire leaves. Keweenaw countv in clavev soils. Rare. 



Caryophijllacecr. 



Cerastium semidecandrum Lin. was collected near Clifton, in August, 

 1898. Only a few specimens were seen. 



Arenaria serpyllifolia L. var. tenuior Koch, a very slender, delicate 

 form, is found in woods near Copper Harbor. 



Ra nun Cilia cew. 



Aquilegia vulgaris Lin., the common purple columbine of the gardens, 

 has escaped in places. 



Cruciferce. 



Braya humilis {Meyer) Rohinson was collected at Copper Harbor in 

 July, 1895. An occasional specimen may be found in crevices of rocks 

 along the lake shore, but it is very rare. 



Erysimum inconspicuum (*S'. Wats.) MacM. var. syrticolum {Shel- 

 don), {E. syrticolum Sheldon, Bull. Torr. Club, 20, 285, 1893), differs 

 from the species in its more robust habit, paler pubescens, and stigma 

 more evidently two-lobed. Reported from Keweenaw county as E. par- 

 viflorum. 



Rosacece. 



Prunus cuneata Raf. is frequent along the rocky shores of Keweenaw 

 county. 



Rubus Canadensis Lin. {R. Millspaughii Britton) is common in Ke- 

 weenaw county. 



Other species, according to the recent revision, that are frequent in 

 the Lake Superior district are Rubus frondosus Bigel: R. argutus Link, r 

 R. procumbens Ph., {R. Canadensis Am. Authors non Lin.) ; R. Bailey- 

 anus Britt. (also common in and around Detroit) ; and R. nigricans^ 

 Rydh.; R. Ensleni Tratt. is frequent near Rochester and Detroit. 



