Dicotyls or Exogenous Plajits. 33 



sterile flowers in small heads, cupule 4-valved, nuts triangular Fagus. 1 



Sterile flowers in slender catkins, cupule a prickj' bur Caslanea. 2 



Sterile flowers in slender catkins, cupule scaly, fruit an acorn Quercus. 3 



1. Genus FA'-GUS. — Tree with a close smooth ash-gray bark; 

 leaves strongly straight-veined, from slender tapering buds. 



Fa'-gus at-ro-pu-nic'-e-a (Marsh.) Sudw. {F.ferruginea Ait.) Beech. 

 — Leaves oblong-ovate acuminate, distinctlj- and often coarsely toothed. 



2. Genus CAS-TAN'-E-A. — Trees or shrubs; sterile flowers in long 

 cylindrical showy white catkins, fertile flowers few in an ovoid and 

 very prickly involucre. 



Cas-tan'-e-a den-ta'-ta (Marsh.) Sudw. [C. satava van americana 

 Gr.) Chestnut. — A very large tree, leaves oblong -lanceolate, long 

 acuminate, serrate with coarse pointed teeth, smooth and green both 

 sides. 



Cas-tan'-e-a pu-mi-la (L.) Mill. Chinquapin. — A spreading shrub or 

 small tree; leaves oblong, acute, serrate with pointed teeth, luhite 

 downy beneaili. Reported in southern Ohio. 



3. Genus QUER'-CUS. — Mostly large trees; the fertile flowers 

 scattered or somewhat clustered, the ovary enclosed in a scah- bud- 

 like involucre which becomes a cup around the acorn. 



A. White Oaks. Leaves lyi-ate oi- simialr pinnatifid. 



Quer'-cus al'-ba L. White Oal(. — Leaves pale or glaucous beneath, 

 bright green above, obovate-oblong, obliquely cut into 3-9 oblong or 

 linear or obtuse, mostly entire lobes; cup saucer-shaped, rough and 

 naked, inuch shorter than the ovoid or oblong acorn (1 inch long.) 



Quer'-cus mi-nor (Marsh.) Sarg. [O. stellata Wang.) Iron Oak ; Post 

 Oak. — Leaves grayish or yellowish-downy beneath, pale and rough 

 above, thickish, sinuately cut into 5-7 rounded, divergent lobes, the 

 upper ones much larger and often truncate or 1-3 notched; cup deep 

 saucer-shaped, naked, one-third or one-half the length of the ovoid 

 acorn C/z-H inch long.) 



Quer'-cus ma-cro-car'-pa Mx. Bur Oak. — Leaves obovate-oblong, 

 lyrate pinnatifid or deeply sinuate lobed or nearly parted, sometimes 

 nearly entire, downy or pale beneath, the lobes sparingly or obttisely 

 toothed or the'smaller ones entire; acorn broadly ovoid, 1-1 j4 inches 

 long, half immersed or enclosedr»by the fringed cup. 



