No. 411.] NORTHERN APETALOUS FLOWERS. 199 
northern regions, and have been developed to endure severe 
climatic conditions. They are or were wind-fertilized, the 
moncecious or dicecious flowers appearing in early spring, when 
there are no leaves to intercept the pollen. 
There are about thirty-five species of the Juglandacez, which 
include the walnut and hickory, large trees valuable for timber 
and fuel. The flowers are green; the staminate form a long 
drooping ament, while the pistillate are solitary, or few in a 
cluster. The perianth is present in both forms. In Juglans 
there are four narrow petals in the sinuses of the calyx; but 
in Hicoria they are wanting. An abortive ovary rarely occurs 
in the staminate flowers. 
In the Myricacez, or bayberry family, neither the male nor 
female flowers possess a perianth, but its place is taken by 
several bracts near the flower. 
The Salicacez form a large family confined almost entirely 
to the north temperate and arctic zones. It includes the pop- 
lar and the willow. The poplar has no perianth, but the recep- 
 tacle is extended to form an oblique, cup-shaped disk. In early 
spring the pollen is expelled forcibly a short distance by the 
elastic purple anthers. In the genus Salix so variable are the 
species and so freely do they hybridize that any entirely satis- 
factory treatment from a systematic standpoint is impossible. 
The Swedish botanist Anderson, whose standard monograph, 
published in the Prodromus of De Candolle, was the work of 
nearly twenty-five years, declared that he never saw two speci- 
mens of Salix nigricans, which has one hundred and twenty 
synonyms, that were exactly alike. In Great Britain the num- 
ber of species have been placed all the way from twelve to 
eighty. This genus is exceedingly interesting to the evolu- 
tionary botanist, since it so fully refutes the ancient dogma of 
the constancy of species. Though the flowers were formerly 
anemophilous, they are now fertilized by insects. There is an 
abundance of honey, a sweet perfume, and the bright yellow 
stamens render the blossoms very conspicuous. As an evi 
dence of their attractiveness, it may be mentioned that they 
are collected in England for decorative purposes on Palm 
Sunday, and are offered for sale in New England cities by 
