1918] St. John,—Spiranthes in Dover, Massachusetts 113 
Another collection of this puzzling plant (St. John, no. 2,046) 
showed likewise a blending of the characters of S. vernalis and S. 
gracilis, but in this case they were combined differently. The speci- 
mens resemble S. gracilis in the size of the corolla and the quadrate 
shape of the lip; they resemble S. vernalis in having the summit of 
the culm pubescent as in that species; they show characters inter- 
mediate between those of the two species in that the lip is partially 
suffused with green and is somewhat crisped at the margin, while the 
spirals of the spike are fewer and more distant than in 8. gracilis but 
not as much so as in S. vernalis. These plants are without doubt of 
the same nature as those collected at Easton, Massachusetts, and 
described as S. X intermedia Ames! As in Dover, the plants in 
Easton were growing in the immediate proximity of the alleged 
parents, S. gracilis and S. vernalis.2 The second occurrence of this 
natural hybrid, at a different station is a noteworthy bit of evidence 
towards Prof. Ames’s suggestion that this apparently fertile hybrid 
may rapidly establish itself as a distinct species. There is every 
reason for the supposition that at this second known station the 
crossing has again occurred, instead of the supposition that the plant 
has spread from the original station at Easton. 
Close observation and study of these specimens from Dover in the 
fresh condition seems to confirm Prof. Ames’s statement è that “ Spir- 
anthes X intermedia is a non-Mendelian hybrid. It is intermediate 
throughout, the characters of both parents being merged in all the 
important vegetative and floral parts.” 
In order to bring out any relation between the location of the hybrid 
plants and those of the parent species, the writer made a census of 
their occurrence in this part of Dover. Mrs. Everett’s field in which 
Spiranthes vernalis has grown for at least twelve years is nothing but a 
rather dry hayfield on a gentle south slope in the western and higher 
part of Dover. A definite ridge running across it divides this six 
acre field into two nearly equal parts, one to the west, and one to the 
east, which is lower, with a definite gully running through it. This 
1 Ruopora, v. 262 (1903). 
2 Prof, Ames originally described S. X intermedia as a hybrid of S. gracilis (Bigel.) Beck and 
S. praecor Watson, but he later demonstrated [Ames: Orchidaceae, Fasc. i. 113-21 (1905)] 
that the northern plant which he had called S. praecor, should be treated as S. vernalis Engelm. 
& Gray. Hence the hybrid X S. intermedia Ames is to be considered as one between S. gracilis 
(Bigel.) Beck and S. vernalis Engelm. & Gray. 
3 Ruopora, v. 263 (1903). 
