VEGETATIVE REPRODUCTION IN AN EPHEDRA 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 172 
WwW. i. @ faiws 
(WITH FIVE FIGURES) 
When the branches of many plants are covered with soil or 
even make contact with it, they may put out roots and produce 
new plants. This method of reproduction is common among 
angiosperms and to a less degree among gymnosperms, where 
heretofore it has been reported only for Coniferales. Many species, 
distributed among Abies, Picea, Pinus, Larix, Pseudotsuga, Thuja, 
Chamaecyparis, and Cryptomeria, produce new plants by the 
rooting of horizontal branches which then either erect the tip of the 
rooting branch or send out erect lateral shoots. The unfortunate 
term “layering” has been applied to this method of vegetative 
reproduction. 
The latest account for a gymnosperm is that of Cooper’, who 
describes “layering” in Abies balsamea and cites the scanty 
literature of the subject. 
Until now no special method of vegetative reproduction has 
been reported for Gnetales, perhaps because the relative inaccessi- 
bility of the group has prevented careful field studies. 
In September ro11 occasional clumps of an Ephedra were found 
on the very steep rocky sides of the cafion of Rifle Creek, near the 
southern boundary of the White River forest reserve in western 
Colorado. This Ephedra is probably conspecific with E. nevadensis, 
although differing from the latter in some minor characters. 
Rifle Creek, where it falls over the edge of the White River pla- 
teau, for some miles has carved out of very hard limestone a box 
cafion with walls in some places rising perpendicularly to a height 
of more than 150 meters (fig. 1), or even leaning outward over the 
cafion floor. Emerging from the box cafion the stream flows for 
OOPER, Wrt.1aM S., Reproduction by layering among conifers. Bot. Gaz. 
* Coo 
52: 369-379. fig. I. 1911 
439] - [Botanical Gazette, vol. 55 
