

GREENE FTELEA IN THE WEST AND SOUTHWEST. 71 



gonus; nevertheless the whitisli and shining twigs attest its being really of the 

 present singiUar group of northern Arizona^ though differing considerably from inost 

 others as to its broad obovate leaflets of rather thinnish texture. 



43, Ptelea nitida, s]). nov. 



Shrub perhaps low, the branching at least eonipai't, the fructification copious, in 

 short and very few-flinvered panicles; all twigs and branches whitish, very smooth 

 and somewhat shining: leaves small, of the same hght green on both faces, glabrous, 

 strongly punctate; mid<lle leaflet ovate-lanc^eolate, 3 to 4 cm. long, acntish at each 

 end, obscurely crenulatc, the laterals oval to lanceolate and from nearly or quite 

 as large to smaller by about one-tliird, all sessile: samaras large for the leaves, 

 all triquetrous, the faces round-obcordate, 1,5 cm. hi length and breadth, retuse at 

 base but obcordate at the broad summit; body oval, of less than tlie M'idtli of the 

 wing, very faintly eircumvalhite, but also the rugosity equally low and obscure, a?J 

 is also the reticulation of the wing, the fruit as a whole remarkably smooth and pol- 

 ished, the scattered punctuation hardly more obvious. 



Species known to me only as in the IIerl)armm of the California Academy from 

 somewhere in the Grand Canyon of the Colorado in Arizona, collected by E. 0. 

 Wooton, July 8, 1S92. 



44. Ptelea argentea, sp. nov< 



Twigs whitisli and poli^shed, much smoother than in any others of the group, 

 neither ridges nor glands obvious to the unaided eye: leaves hard and quite coria- 

 ceous, of a bright but not shining green above, very pale and witli a silvery gloss 

 beneath, yet everywhere perfectly glabrous, odd leaflet lanceolate or even slightly 

 rhombic-lanceolate, acute, 3 to 4.5 cm. long, laterals smaller by about one-fourth, 

 hniceolate, all sessile, obscurely snbserrulate: samaras large for the foliage, usually 

 triquetrous, those 2-wiuged and plane-suborbicular but broader than long, the breadth 

 1-5 cm.; body in all elongated-obovate, marked throughttut its length with obscure 

 low but quite transverse ridges and with low circnmvallation, the dots many, yet 

 inconspicuous; style slender, not long, yet longer than the short cuneiform stipe. 



This s])ecieSj remarkable for its leathery foliage, silvery-lustrous beneath, is known 

 to me only as collected by Dr. F. H. Knowlton, somewhere in the Grand Canyon of 

 the Colorado, September 10, 1SS9, the specimens filling two sheets in the National 

 Herbarium (one tlie type). Notwithslau^hng the luster on the lower fate of the 

 leaflets, I am unable to detect any indument there, either lepidote or otherwise, 



45. Ptelea neglecta, s|>. nov. 



Mature twigs of the season hght chestnut-color, short-rugulose, glandular-tuber- 

 culate, glabrous, those a year oi<l whilish, smoother and shming. leaves equally 

 Iight-green on both lai^^s, subcoriaceous, glabrous, conspicuously and darkly gland- 

 dotted, odd JeaHet lanceolate, :15 to 5 cm. long, obtuse, the pair commonly little 

 smaller, e(iual-sided, all obscurely or not at all crenate, sessile: samara very large 

 lor the loliage, 2 to 2.1^ cui. long, broadly oval or obovate, letuse at both ends, body 

 rather narrowly oval and long, ol the width ol the wing, not rugose but very strongly 

 gland-dotted, the dots, Jiowever, in some thsposed in rather definitely transverse 

 lines, style and stq>e subequal^ botli slunt. 



Near Kanab, southern L'tali, A. Wetherilb 1897; tlie only specimens in the Herb- 

 arium of the Calitorma Academy, consisting <^i two sorry fragments, but well in 

 fruit, and evmcing a marked sp(*cies. 



46. Ptelea triptera, sp* nov. 



Shrub apparently low, the w^iitisli or straw-colored l^rancht^s more glandular- 

 tuberculate than rugose: leaves small, in maturity subcoriaceous, yellow-green 



-L 



