160 PROCEEDINGS OF THE AMERICAN ACADEMY 



Canotia holacantha, Toit. in Pacif. R. Rep. iv. G8 ; Benth. & 

 Hook. Geu. i. 616 (where the radicle is inadverteutly said to be 

 superior); Brewer & Watson, Bot. Cahf. i. 190. — Arizona, in the 

 arid desert region, especially along mountain water-courses, Emory, 

 Bigelow, and various other collectors, in fruit, first collected in flower 

 by Palmer, and recently by Rothrock in Wheeler's Expedition. 



A genus of hitherto undetermined affinity. Dr. Torrey, who knew 

 only the fruit, with calyx and filaments persistent at its base, compared 

 it with Eucryphia ; upon which Beutham and Hooker appended it, alono- 

 with that genus and Euplironia, to Rosacea:, tribe Qalllajece. What- 

 ever may be said of those genera, this is certainly not Rosaceous. 

 Baillon, the first botanist to publish any thing upon the genus since 

 the flowers were known, and who describes the '• discum crlandulosum 

 incrassatum " under the ovary (but wrongly describes the calyx as 

 valvate and the ovules as anatropou-), refers Canotia without question 

 to Celastracece.* This is better than Rosacece, and the inferior radicle 

 tells in its favor, as against the view which I take, having now for the 

 first time examined the floweis. But I am confident that the plant 

 belongs to the Rutacece. The structure of the gynol)ase, as I should 

 call it, points strongly in this direction. This large and fleshy or, when 

 dry, rather corky body upon which the ovary is mounted is broader 

 than the latter in the blossom, as well as of twice its height; and is 

 so confluent with it that, upon superficial observation, it would be taken 

 for a component part of it. But it is solid within, and has a papillose- 

 glandular surface, unlike that of the ovary it supports, which is smooth. 

 Its likeness to that of Rue is manifest ; and in Thamnosma the same 

 body becomes stipitiform. I find no trace in Canotia of a proper disk 

 around the base of this, which is conspicuous in Thamnosma, As the 

 fertilized ovary enlarges, it soon becomes broader than the gynobase 

 as well as longer ; in the fruit the latter so inconspicuous that it has been 

 ovei'looked. The wood and bark are not bitter to the taste, in the 

 manner of most Simarubacece (which in a comprehensive consideration 

 of relationships must be taken along with Rutacece), nor is the surface 

 at all pustulate- or tuberculate-glandular as in Thamnosma. But in 

 the petals, and especially in the sepals and minute bracts of the inflo- 

 rescence, I discern evident traces of the Rutaceous oil-glands. Faint 

 and few though they be, they suffice to confirm the affinity. 



There are four of these spartioid green-barked and raainl}'^ leafless 

 shrubs in the dry Arizonian region. Thamnosma montanum, Torr., 



* Adansonia, x. 18, & Hist, des Plantes, vi. 43, 1875. 



