Some HorticuLtTuRAL FERN VARIATIONS 9 
horticultural variations but in small numbers, probably 
because they are much less widely cultivated than 
exaltata. This species has been cultivated more than 
fifty years, in increasing amounts as time passed. By 
1895 it had become a comparatively well-known house 
plant with the popular name of “sword fern.” About 
this time florists became aware that they were growing 
under this name two different ferns, one rigid, rather 
erect-leaved, with plane pinnae, and spore-fertile, the 
other more flexible, drooping, with slightly undulated 
pinnae, and mainly, if not entirely, spore-sterile, repro- 
ducing only by runners. These two forms are said to 
have been referred to the late George E. Davenport of 
the Fern Society for diagnosis, the second form being — 
named by him N. exaltata bostoniensis because of its 
prevalence and possible origin near Boston. 
The old sword fern then practically went out of 
existence as a trade species, and the Boston fern was 
grown in ever increasing numbers. Nowadays the few 
dealers who advertise the sword fern or N. ezaltata 
seem always to have it confused with other species, NV. 
cordifolia or ‘‘N. tuberosa.” True exaltata, as I consider 
it, I know only as Porto Rican plants collected for the 
New York Botanical Garden. 
The fifty varieties already referred to have all come 
from the Boston variety of N. ezaltata. Beginning 
about 1900 there has been an increasing number of new 
forms appearing in the greenhouses each year. About 
fifty have been named as commercial varieties. Prob- 
ably almost an equal number have been discarded or are 
still held for further tests to determine their value. It 
has been my privilege to study these forms in two ways; 
first, by frequent visits to the establishments of com- 
mercial growers where I have seen them literally by the 
hundred thousand; second, by assembling at the Brook- 
lyn Botanic Garden a collection of all obtainable varie- 
