1921] Ames, — Notes on New England Orchids, — I. Spiranthes 79 



normal seeds. Material from other stations (Webster, Mass., and 

 Toronto, Canada) was found to be polyembryonic and subsequent 

 studies seemed to confirm the belief that polyembryony is a reliable 

 guide to the recognition of the wet meadow and bog form of »S. 

 cernua. Leavitt stated this positively in his paper on the Geographic 

 Distribution of Closely Related Species. 1 In the late summer of 

 1920 I made careful studies of material collected in Easton and Sharon 

 and confirmed the accuracy of Leavitt's observations. Specimens 

 which grow associated with Calopogon and Arethusa are polyembry- 

 onic without exception according to my observations. The same 

 is true of specimens that grow in what is usually termed sour soil. 

 In dry fields where ericaceous plants are encroaching the polyem- 

 bryonic form also prevails. In woodlands and rich upland pastures 

 polyembryonic forms are wanting, their place being taken by the 

 form with normal seeds that we now refer to Spiranthes cernua var. 

 ochroleuca. 



Spiranthes vernalis Engel. & Gray, as far as the northern forms 

 referred to it are concerned, may be simply a hybrid between S. 

 cernua and »S. gracilis. In September, 1920, I found specimens of a 

 Spiranthes which showed unmistakable signs of hybridity. They 

 were almost perfectly intermediate between S. cernua and S. gracilis 

 with both of which species they were associated in a small run-out 

 field on the shore of Wilbor Pond near the Easton-Sharon line. These 

 hybrids resembled closely some of the more robust forms of so-called 

 S. vernalis collected in the neighborhood of South Easton in 1903 

 and 1904. Only three plants were found. Intensive exploration of 

 the surrounding fields failed to reveal additional specimens. In its 

 proportions the suspected hybrid resembled S. cernua very closely 

 but was much taller and more slender. The flowers had the yellow- 

 ish tinge that is sometimes so characteristic of var. ochroleuca. The 

 lateral sepals were wide-spreading as in S. gracilis and the flowers 

 were arranged in slender, elongated racemes that seemed to consist 

 of several spirals. The characters of the hybrid are very clearly 

 shown in the accompanying plate (128). Whether or not the south- 

 western forms of S. vernalis originally described by Engelmann and 

 Gray were of hybrid origin and comparable to this northern form is 

 a question for which the answer may be forthcoming as a result of 

 experimental evidence. All of the species that enter into the ques- 



1 American Naturalist, xli (1907) 234. 



