374 PROCEEDINGS OF THE AMERICAN ACADEMY 



10. Isopyrum Hallii, n. sp. Elatum ; caule 1 - 2-pedali) superne 

 bifoliato ; foliis amplis triternatis summove biternato ; foliolis obovato 

 cuneatis (sesqui - bipollicaribus) irregulariter trifidis apice incisis ; flori- 

 bus in pedunculo comrnuni elongato nudo vel folioso-bracteato nunc 

 bifido pluribus umbellatini dispositis ; sepalis 5 obovatis stamina nu- 

 merosissima baud superantibus ; filamentis apice clavatis ; petalis nullis ; 



R. Occident alis Nutt. in Torr. & Gray, Fl. 1, p. 22, excl. char, pro parte. 

 R. hispidus Hook. Fl. Bor.-Arn. p. 19, pro parte. — Oregon, British Columbia, 

 Sitka. Nuttall's species was founded, as his specimens testify, upon the large- 

 flowered and usually very shaggy-hairy plant, which is not uncommon on the West- 

 ern coast, although seldom collected in fruit (I have ripe carpels only in a specimen 

 collected by Burke) ; but the description of it somehow got badly mixed up with the 

 R. recurvatus of Bongard, and Nuttall's own R. tenellus, i. e. with the following 

 species. To this pertains all that relates to the long style, comparatively small 

 narrow petals, &c. 



Var. canus. R. canus Benth. PI. Hartw. p. 294. — California, in moist valleys of 

 the Sacramento. Evidently a more canescent form of the present species. I have 

 not seen the fruit, nor any other specimens answering to Hartweg's no. 1626. The 

 specimens of Bigelow's Bot., Whipple's Expedition, referred to R. canus, probably 

 belong to R. Californicus. 



* * Micranthi, petalis (5) haud ultra lineas 3 longis angustis luteis ; stylo elon- 

 gato. 



■<- Occidentales ; foliis supremis vel segmentis lanceolatis integerrimis ; petalis 

 calycem excedentibus ; carpellis in capitulo 10-20. 



R. Nelsonii. R. recurvatus var. Nelsonii DC, Syst. 1, p. 290. R. recurvatus 

 Bong. Veg. Sitcha, p. 123, non Poir. R. occidentalis Torr. & Gray, 1. c. pro 

 parte. — Oregon to Sitka. Forma typica; foliis latioribus ; acheniis pilis parcis 

 rigidis pi. m. conspersis nunc glabratis stylum ejusdem longitudinis maxime un 

 cinatum gerentibus. 



Var. tenellus gracilior; foliis parvulis, lobis angustioribus ; stylo quam 

 achenium lajve breviore. R. tenellus Nutt. in Torr. & Gray, 1. c. — Northern Cali- 

 fornia (Bolander) to Vancouver's Island, &c. There is a R. tenellus of Viviani, 

 from Egypt, perhaps of earlier date than Nuttall's, which, though overlooked by 

 Boisser, may claim to be used. Nuttall's name is not a good one for the whole 

 species as now regarded ; and his character is somewhat misleading as to " flowers 

 minute " (the petals- are sometimes a quarter of an inch long), and very much so 

 as to the " minute style." The style is, indeed, less prolonged than in what I take 

 for the type of the species ; and this with the smoothness of the achenium and 

 something in the habit of the plant might forbid the union : but there are transi- 

 tions between the two forms. 



-t- +- Orientales ; foliis amplioribus ; petalis calyce brevioribus ; carpellis pluri- 



mis in capitulo denso. 

 R. recdrvatus Poir. — Canada to Florida. 



