I9IS-] TRELEASE— LARGE FRUITED AMERICAN OAKS. 11 



Wishing materials that should throw light on this question, I 

 turned in 1912 to my amiable correspondent, Dr. Purpus, who was 

 then in eastern Mexico : but before my letter reached him. Dr. 

 Purpus had gone into southern Mexico. The result of my appeal, 

 therefore, was not further specimens of Quercus insignis, but col- 

 lections of an equally large and almost equally large-fruited white 

 oak which appears to be characteristic of the Chiapas region. With 

 somewhat similar but more deeply toothed leaves about 7 X 20 cm., 

 equally short-petioled, this combines a stoutly stalked turbinate 

 cup as much as 60 mm. in diameter, the scales of which are barely 

 if at all free at tip with their bases connate in zones ; and the 

 ovoid pointed acorn measures 40-50 X 50-60 mm. Though closely 

 related to Q. insignis, this species is so distinct in its collective char- 

 acters as to stand as the type of a separable group of white oaks, 

 and it has been called Q. cyclobalanoides^ because of its very peculiar 

 cup-markings. 



EXPLANATION OF PLATES. 



(All figures are of natural size.) 

 Plate I. 



Quercus macrocarpa. Above, three acorns from a very small-fruited 

 Michigan tree (Pieters), partly with and partly without fringe to the 

 cup, and a single fruit of the largest and "mossiest" type from Illinois 

 (Adams). Below, two of the more typical acorns of different cup-depth, and 

 a cup showing a not infrequent inrolling of the inner scales, also from 

 Illinois (Adams). 



Plate II. 



Above, two cups and three acorns of the large-fruited Mexican 

 red oak, Quercus chiapasensis (Purpus). Below, basal and side view of 

 two acorns of the large-fruited Chinese oak, Pasania cornea (after pho- 

 tographs by Fairchild). 



Plate III. 



Above, two fruits of the Mexican ring-scaled white oak, Quercus cyclo- 

 balanoides (Chiapas, Purpus). Below, a fruit of the great-acorned Mexican 

 Tvhite oak, Quercus insignis (Huatusco, Purpus). 



The University of Illinois, 

 March 8, 1915. 



9 Quercus cyclobalanoides n. sp. Arbor grandis ; foliis brevipetiolatis, 

 acutis, oblanceolatis, mucronato-dentatis : fructu magna; cupula turbinata, 

 luteo-tomentosa, pluriannulata; glande ellipsoidea, sub 50 mm. diametro. 

 Quercus Insignes valde affinis, sed sectio distincta, Cyclobalanoidese, constitu- 

 ens. — Q. insignis Journal of Heredity, 5 : 407. /. 12. 1914— not Martens and 

 Galleotti, /. c. 



