FLOWERING PLANTS AND FERNS OF ARIZONA 517 



This seems to be the form interpreted by Wooton and Standley 75 

 as P. angustifolia Benth. The latter was described from Mexican 

 specimens, whereas P. pallida is mainly a species of the high plateaus 

 of central and northern Arizona. Additional names published by 

 Greene, based on Arizona types, all probably synonyms of P. 'pallida 

 are: P. argentea, P. deganSj P. lutescens, P. ntglecta, P. nitida, P. 

 maligna, and P. triptera. 



2. Ptelea angustifolia Benth., PL Hartw. 9. 1839. 



Ptelea bald win ii of authors. Not Torr. and Gray. 

 Ptelea jucunda Greene, Contrib. U. S. Natl. Herbarium 10: 63. 

 1906. 



Apache County to Hualpai Mountain (Mohave County), south to 

 Cochise and Pima Counties, 3,500 to 8,500 feet, commonly in the 

 yellow pine belt, mostly in canyons, May and June. New Mexico, 

 Arizona, and Mexico. 



P. angustifolia is perhaps not specifically distinct from P. tornentosa 

 Raf. It differs from the eastern P. trifoliata L. (and var. mollis Torr. 

 and Gray) chiefly in its usually narrower leaflets and in the thicker 

 wings and relatively large body of the fruits, which are more often 

 emarginate at base and apex. Additional, probably synonymous, 

 names published by Greene on the basis of Arizona types, are: P. 

 att/ita, P. crenata, P. similis, and P. tortuosa. 



The typical form has the foliage and twigs more or less permanently 

 pubescent. A glabrate form, usually with narrower leaflets, is var. 

 cognata (Greene) Kearney and Peebles (P. cognata Greene ibid. p. 62), 

 the type of which was collected in the Huachuca Mountains (Wilcox 

 477). P. betuiifolia Greene, based on a specimen collected at Fort 

 Bowie (Fisher in 1894), seems to be a synonym. This variety is more 

 common than the typical form in the southern part of the State and 

 begins to flower as early as March. 



60. SIMARUBACEAE. Simaruba.family 



1. HOLACANTHA. Crucifixion-thorx 



A large shrub, of grotesque appearance, intricately branched, with 

 short stout sharply spinose branches ; leaves reduced to small deciduous 

 scales; inflorescences very dense, many-flowered; flowers dioecious, 

 small, greenish yellow; petals commonly 7 or 8; stamens 12 or more 

 in staminate flowers; fruit a ring of 5 or more nearly separate, diver- 

 gent, 1-seeded, drupelike carpels. 



1. Holacantha emoryi A. Grav, Amer. Acad. Arts and Sci. Mem. ser. 

 2, 5: 310. 1855. 



Pinal. Maricopa, Pima, and Yuma Counties. 2.000 feet or lower, 

 frequent but not abundant on desert plains. June and July, type from 

 between Tucson and the Gila River. Southern Arizona, southeastern 

 California, and northern Mexico. 



The fruits persist for years, so it is usually possible to identify each 

 preceding season's fruit clusters by the degree of weathering:. The 

 plant attains a height of 3.5 m. (12 feet) (pi. 16). 



» Wooton, E. O., and Standley, P. C. flora of new Mexico. Contrib. U, S. NatL Herbarium 



19: 1-794. 191o. (See p. - 



