124 THE LATER EXTINCT FLORAS OF NORTH AMERICA. 



Order CORNACE/E, 



Cornus Newberryi Hollick. 1 



PL XXXVII, figs. 2-4. 



Cornus acuminata Newb. Ann. N. Y. Lye. Nat. Hist., Vol. IX (April, 1868), p. 71. 

 (not C. acuminata. Weber, Palseontogr. , Vol. II (1852), p. 192); Ills. Cret. and 

 Tert. PI. (1878), PL XX, figs. 2-4, under C. acuminata. 



" Leaves ovate or oA r ate-lanceolate, long-pointed, acute, entire, nar- 

 rowed at the base, and slightly decurrent; midrib distinct, straight or 

 curved toward the summit, following the course of the frequently deflexed 

 point; lateral nerves numerous, regular, and nearly parallel, simple, lower 

 ones straight with a slightly curved summit, upper ones becoming pro- 

 gressively more arched upwards, when near the apex of the leaf curved in 

 so as nearly to join the extremity of the midrib; tertiary nervation so 

 fine as to be hardly perceptible in the fossil state." 



The specimens of these leaves contained in the collection of Dr. 

 Hayden are quite numerous and pretty well preserved. Although there is 

 no fruit of Cornus associated with them, there pan be little doubt that they 

 are properly referred to that genus. The aspect of the leaves of Cornus is 

 peculiar, and such as is usually readily recognizable at a glance. This 

 facies is given by the outline as well as the nervation. The outline is 

 usually more or less accurately oval, the margin entire, the base rounded 

 or slightly wedge-shaped, the summit pointed and laterally flexed. The 

 nervation is very clearly defined, the midrib strong at the base, tapering 

 gradually till it reaches the extreme point of the apex ; the lateral nerves 

 pinnate, approximated below, more remote above ; all simple, arched 

 upward, those near the summit being drawn in to join the midrib. 



This latter characteristic is visible in all the species of Cornus known 

 and is particularly noticeable in the common herbaceous species of C. Can- 

 adensis. It is also very marked in C. Florida, C. sericea, C. altemifolia, etc. 



The tertiary nervation is generally delicate and sparse, the tertiary 

 branchlets running across obliquely, but with nearly a straight course, 

 between the adjacent lateral nerves. In all these characters, as far as they 



1 Dr. Newberry's original published name, C. acuminata (1868), was antedated by Weber's, 

 C. acuminata (1852), given to another species. It therefore became necessary to change the 

 name, — A. H. 



