BOTANICAL MUSEUM LEAFLETS 
HARVARD UNIVERSITY 
~ 
( 
CaMBRIDGE, MassacnuseTTs, JUNE 22, 1973 VoL. 23, No 
A NEW SPIRANTHES 
FROM THE GRASSLANDS 
OF CENTRAL NORTH AMERICA 
BY 
Cuarues J. SHEVIAK* 
The genus Spiranthes L. C. Rich. is highly complex 
and in eastern North America has caused some confusion 
among taxonomists and others who have had cause to 
determine occasional specimens. Many species are with 
difficulty separated from their allies, and apparent hy- 
brids occur with sufficient frequency to obscure specific 
distinctions. Among the species most notorious for such 
behavior is S. cernua (L.) L. C. Rich. This species com- 
prises various ecological and morphological races, at least 
some of which appear to intergrade and hybridize with 
other species. Spiranthes cernua has needed definitive 
study, but wide field experience is a prerequisite for such 
an undertaking, and, thus far, no one has attempted to 
clarify the situation. At present, two varieties in addi- 
tion to the heterogeneous assemblage considered typical 
are frequently recognized. 
Variety odorata (Nutt. ) Correll differs from more typi- 
cal SS. cernua in its rhombic-ovate lip, stoloniferous roots, 
and its occurrence principally in coastal plain swamps. 
[t is often appreciably more robust and foliose than typi- 
cal WS. cernua. This taxon has historically been treated as 
* Botanical Museum, Harvard University. 
[ 285 ] 
