THE CENTRAL AMERICAN SPECIES OF QUERCUS 39 



glabrate or pubescent, with numerous prominent light lenticels; cups 

 usually about 14 mm. broad (occasionally 20 or only 8 mm.), usually 

 hemispheric but sometimes deeply cup-shaped or deeply saucer-shaped, 

 the margins straight or occasionally flaring, the scales narrowly ovate 

 or cuneate, somewhat or not at all thickened basally, the narrowly 

 rounded apices thin and often loosely appressed, densely puberulent 

 or tomentose, buff or the glabrate scale tips deep red; acorns 15 to 23 

 mm. long, 8 to 15 mm. broad, ovoid to oblong or long-conic, obtuse 

 or acute, smooth or longitudinally furrowed in drying, light brown, 

 glabrate, one-third or only one-fifth included. (See pis. 44 to 49.) 



Range: Mountains of Guatemala and Chiapas; type from Guatemala 

 (von Warscewicz 10) without further data. 



Quercus pilicaulis is a well-marked and very constant species in its 

 fundamental characters (texture, veining, and pubescence of the leaves, 

 scales of the cups, and acorns). Yet, in leaf form, size and shape of 

 fruit, and length of peduncle it presents numerous variations and 

 combinations of variations which, in single specimens, seemed worthy 

 of formal names. It does not now seem desirable to separate a forma 

 exserta which in addition to its exserted acorns also has the elongate 

 peduncles of f. elongata, which in turn has the coarsely toothed leaves 

 of f. macrodonta. It rather seems that these variations may all be 

 attributed to single and independently functional genes, which may 

 appear in almost any population of the species. 



Trelease referred this species to the series Pedunculares, but its 

 constantly impressed-veiny leaves with often apiculate teeth and its 

 cup scales with loosely appressed reddish-brown apices clearly indicate 

 the series Reticulatae. 



Specimens examined: 



MEXICO.— Chiapas: Las Casas, February 1939, Martinez 367 (USNA); 

 April 1939, Martinez 368 (USNA); Cintalapa, February 1939, Martinez 378 

 (USNA); Copainala, February 1939, Martinez 379 (USNA). 



GUATEMALA. — Dept. Huehuetenango: without further data, August 1934, 

 Skutch 1078 (F). Dept. San Marcos: above Rio Tacana, near San Antonio, 

 February 22, 1939, Standley 66128 (F, USNA) ; Puente de Nahuatl-aa, near San 

 Marcos, February 22, 1939, Standley 66206 (F). Dept. Quezaltenango: Cerro 

 La Pedrera, south of Quezaltenango, February 18, 1939, Standley 66464 and 66468 

 (F) ; mountains above Olintepeque, February 20, 1939, Standley 65960 (F, USNA) ; 

 above (north of) Olintepeque, January 29, 1941, Standley 85219 (USNA); Cerro 

 Quemado, February 8, 1906, Kellerman 5922 (US) ; Volcan Santa Maria, January 

 24, 1896, Nelson 3721 (US); Volcan de Santa Maria, above Palojunoj, March 6, 

 1939, Standley 67585 (F) ; January 15, 1941, Standley 83582 (USNA); Quezal- 

 tenango, April 6, 1915, Trelease 34, 35, 36, 37, 38, 39, 40, 41, 42 (111 [no. 37, type 

 of f . hurteri]) ; April 7, 1915, Trelease 32, 33 (111.) ; 1922, Hurter 3, 3b, 4, 5, 6, 7, 

 8, 9 (111). Dept. Totonicapan: between San Francisco El Alto and Momos- 

 tenango, January 19, 1941, Standley 84099 (USNA); region of Chui-quisis, 

 between Totonicapan and Desconsuelo, January 23, 1941, Standley 84398 (USNA). 

 Dept. Chimaltenango: Chichavac, November-December 1930, Skutch 50 (111, 

 US) ; February 28, 1933, Skutch 296 (Mi, US) ; November 14, 1933, Skutch 684 

 (US); Skutch 685 (111 [isotype of f. concava]); Skutch 686 (111, US); Skutch 687 

 (111 [isotype of f. elongata\) ; Skutch 688 (111, US) ; November 19, 1933, Skutch 728 

 (US) ; Cerro de Tecpam, region of Santa Elena, December 26, 1938, Standley 

 609 45 (F) ; Barranco de la Sierra, southeast of Patzum, December 31, 1938, 

 Standley 61509 (F, USNA). Dept. Guatemala: Sapote, March 1890, Smith 1968 

 (G, NY, US); near Fiscal, December 12, 1938, Standley 59617 (F, USNA). 

 Dept. Sacatepequez: Chillani, April 3, 1921, Rojas 367 (US). Dept. Jutiapa: 

 Los Llanitos, near San Jose Acatempa, December 21, 1938, Standley 60599 (F). 



Series Opacae Trel., Mem. Nat. Acad. Sci. 20: 92. 1924. 



Shrubs or small trees with slender glabrate twigs; buds rounded, 

 the stipules persistent or caducous; leaves small, thick and hard, 



