No. 10 
BULLETIN 
OF THE 
~ TORREY BOTANICAL CLUB 
] Apia 904 
Pe, gS aig Saal la oa 
The chimney-shaped stomata of Holacantha Emoryi* 
CHARLES E. BESSEY 
(WITH PLATE 24) 
Last December two fine twigs and a cluster of the ripe fruits 
of the “ burro thorn ” (Holacantha Emoryt Gray) were brought to 
the Botanical Department of the University of Nebraska by Mrs. 
Dorothy Bacon, who had collected them in the Salt River valley, 
near Phoenix, Arizona. They at once attracted attention because 
of their complete leaflessness, and the thorny nature of their 
branches. The shrub is said to grow about three meters high, 
and to form an impenetrable thicket from the ground up. It 
grows in the desert, where it was first found about fifty years ago 
by Major W. H. Emory of the United States Army in one of his 
_ expeditions, In the “Notes of a Military Reconnaisance from 
ort Leavenworth in Missouri, to San Diego in California’ (Wash- 
ington, 1848), a poor drawing of a branch is given on the 
Second plate of Appendix No. 2 (page 157). From an imperfect 
drawing, probably the original of the one given in the plate, Dr. 
George Engelmann surmised that it might be some species of 
Koeberlinia, a most excellent guess, as was afterwards shown. In 
* Seven years ago ( 1897) I read a paper on the peculiar stomata of the ‘‘ burro 
thorn”? ( Holacantha Emoryi Gray) before the British Association for the Advancement 
of Science (at Toronto), accompanying it with a number of drawings. 1 did not print 
“@ Paper at that time, hoping to add to it in certain details before doing so, I wished 
re h 
‘tla’ shoots) in order to study the development of these peculiar stomata. As my 
seat romised material has not yet a , it seems best to publish the paper 
Mm its original form with the figures which accompanied it. 
[The preceding number of the BULLETIN, Vol. 3t, No. 9, for September, 1904 
Bt: AS7-522, p/. 16-23) was issued 4 O 1904. ] 
525 
