1906] Knight, — Notes on our Yellow Cypripediums 93 



SOME NOTES ON OUR YELLOW CYPRIPEDIUMS. 

 Ora W. Knight. 



Though the extreme forms of our native yellow Cypripediums 

 have been recognized as species under the names Cypripedium pubes- 

 cent Willd. (Sp. PI. 4: 143. ISOo) and C. pa n- i florvm Sa.V\sh. (Trans. 

 Linn. Soc. 1: 77. 1791) I have long doubted their sj)ecific distinctness. 

 Study of the plants growing in the field and also of some under cul- 

 tivation in the garden would .seem to prove that we have at best a spe- 

 cies, C. parviflontm Salish., which would ap])ear to be our small 

 flowered plant which has connnonly passed under this name, while 

 the larger flowered form would ai)])car to require the name, Ci/pri- 

 pediiim parviforin7i var. pubescens, in order that its exact relationship 

 be better expressed. 



On May 30, 1901, ^h\ V. M. Hillings found a clump bearing eleven 

 flowering stalks which could be referred under the descriptions in the 

 current manuals to no other species than Cypripedium pubescens. 

 They agreed perfectly with the descriptions in size of flower, compres- 

 sion of lip, shape of foliage and all the characters except color of the 

 blossoms which were bright, not pale yellow. The.se plants were grow- 

 ing in very rich soil in low shady woods. A portion of the plant was 

 pressed and three flowers fi'om it are now in my herbarium. Mr. 

 Billings transplanted jxirt of the cluster into his garden, putting them 

 into less rich soil and in a sutniier spot than where they naturally grew. 

 In 1905 the characters of these plants were .so far changed that they 

 would pass very well for the small-flowered plant, Cypripedium parvi- 

 fionim. The whole plant had become shorter and slenderer with 

 narrower foliage, the lips of the flowers less than an inch in length 

 (some were two inches at time when transj^lanted), lips not appre- 

 ciably flattened laterally and in fact not any longer possessing the 

 characters of the large-flowered plant. 



During the past few years I have annually transplanted into my gar- 

 den clumps of a plant which agreed in all essential characters with the 

 Cypripedium parvi/Jorum of the numuals, save that in most instances 

 the blossoms were pale yellow, not bright yellow, as called for by the 

 descriptions, but some plants had bright yellow blossoms though not 

 otherwise dift'ering. The plants longest growing in the garden (about 

 five years) have increased in size, have larger broader foliage, flowers 

 with lips up to one and three-quarters inches long which are deeper 



