46 MISC. PUBLICATION 4 7 7, U. S. DEPT. OF AGRICULTURE 



cups 20 to 22 mm. broad, hemispheric, the bases rounded or some- 

 what constricted, margins not Enrolled, scales oblong or narrowly 

 ovate, the apices narrowed but truncate or rounded, loosely appressed. 

 finely fulvous-tomentose; acorns depressed-globose or hemispheric, 

 densely fulvous-sericeous or glabrate and light brown, one-half or 

 more included; abortive ovules apical. (See pis. 58 and 59.) 



Range: Mountains of southern Guatemala and Chiapas (about 

 1,500 to 3,000 m.). 



The large cups with loosely appressed scales and long buds with 

 fulvous-cilia te scales adequately distinguish Q. benthami from the 

 other annual-fruited species, whereas the same characters together 

 with its annual fruition separate it from Q. acatenangensis, which 

 sometimes has similar leaves. Sterile specimens of Q. seemanni are 

 very difficult to separate from Q. benthami except by the long, ciliate- 

 scaled buds of the latter. The former species is known only from 

 Costa Rica, however, and there are sufficient fruiting specimens to 

 establish the nature of its cup scales as tightly appressed. 



The annual-fruited species of Erythrobalanus with moderately 

 large cups and loosely appressed fulvous scales would seem to form a 

 natural group. Q. humboldtii, Q. costaricensis , and Q. benthami have 

 this type of fruit in common. However, of these species, Q. benthami 

 is the only one with apical aborted ovules, and Q. costaricensis is the 

 only one with leaves broadly rounded and granular-bullate on the 

 lower surface. Trelease characterized Q. gemmata as having leaves 

 "very obtuse". His photograph of the type clearly indicates it to be 

 conspecific with Q. benthami and shows its very obtuse leaves to be 

 totally lacking apices by which to judge this point. The relationship 

 of Q. benthami is very problematic. It probably is more closely 

 related to the Andean Q. humboldtii than to any other known species, 

 but its apical abortive ovules make its reference to the Andinae 

 difficult. 



Specimens examined: 



MEXICO.— Chiapas: Mount Tacana. August 1938. Matilda 2386 (USNA [3F> : 

 Mount Ovando. November 14-18. 1939, Matuda 3935 (USNA). 



GUATEMALA. — Dept. Sax Marcos: northeast flank of Volcan Tacana, 

 vicinity of San Rafael (3 miles from Chiapas boundary), February 20, 1940, 

 Steyermark 36212 and 36274 (F, USXA) ; near southeast portion of Volcan Tacana, 

 between Conjula and La Union Juarez, February 22, 1940, Steyermark 36376 and 

 36389 (F, USNA) : south slopes of Volcan Tajumulco, above Finca El Porvenir, 

 March 8, 1940, Steyermark 37267 (F). Dept. Quezaltexaxgo: slopes of Volcan 

 Zunil about Aguas Amargas, February 17, 1939, Standley 65408 (F, USXA); 

 Santa Maria, without date, Hartweg 563 (XY[isotvpe]). Dept. Chimaltex'axgo : 

 Chichavac, Xovember 16, 1933, Skutch 692 and 698 (US). Dept. Jutiapa: Volcan 

 Suchitan, northwest of Asuncion Mita, Xovember 18, 1939, Steyermark 31947 (F) 



Series Costaricanses Trel., Mem. Xat. Acad. Sci. 20: 145. 1924. 



Medium-sized trees; twigs thick, from sparsely long-tomentose 

 becoming glabrate and russet brown; buds large, ovoid or elongated, 

 tomentose or glabrate; leaves persistent, medium-sized, elliptic or 

 ovate, obtuse, impressed-veiny and glabrate above, rather persistently 

 loose-tomentose beneath with prominent veins and prominently 

 bullate lamina, petioles short; staminate catkins fulvous-tomentose; 

 fruit annual, short-stalked, rather large, the glabrate cup scales thin 

 and loosely appressed, abortive ovules lateral or basal as in Lepido- 

 balanus. 



Range: Mountains of Costa Rica. 



Includes: Q. costaricensis Liebm. (type). 





