478 



LXXII. CUPULIFERvE. 



[Quercus. 



ovules at the base or the top of the seed. The cotyledons are thick fleshy, 

 as a rule farinaceous, in a few cases oily (candles are made of the acorns 

 of an oak in Jtfew Grenada). 



Of this large genus 281 sp. are described in De Candolle's Prodromus. A. S. 

 (Ersted, in his introduction to "Liebmann, Chenes del'Amerique tropicale," 1868, 

 proposes to divide it into 4 genera, with the following diagnostic characters, three 

 of which contain species described below : 



Styles stigmatose along the inner surface ; male 

 flowers in drooping catkins ; leaves generally 

 serrate or lobed. 

 Scales of cup imbricate 1. Quercus (1-15). 



Scales of cup in concentric belts 

 Styles stigmatose at the apex only ; male flowers 

 in erect spikes ; leaves entire. 

 Scales of cup imbricate ..... 

 Scales of cup in concentric belts 



2. Cyclobalanopsis (16,17). 



3. Pasania (18). 



4. Cyclobalanus. 



Under this arrangement the species of Quercus are American, European, and 

 West Asiatic, whereas the species of the other genera are confined to Eastern 

 Asia and the Indian Archipelago, with one exception, Pasania densiflora, (Erst, 

 of California. The following clavis includes (in brackets) the more important 

 European and West Asiatic Oaks. 



Leaves serrate dentate lobed or pinnatifid ; male fl. in pen- 

 dulous catkins, without rudimentary ovary. 

 Cup with imbricate scales, adpressed or spreading (Quercus, 

 (Ersted). 

 Scales closely adpressed in the ripe fruit, more or less 

 connate at base. 

 ; Leaves persistent until winter, generally beyond the 



appearance of the new leaves; styles linear or 

 linear-clavate. 

 Full-grown leaves tomentose or pubescent beneath. 

 Acorn globose, supported at the base by a flat or 

 slightly concave cup ; main lateral nerves 8- 



12 pair, bifurcating 1. Q. semecarpi folia. 



Acorn cylindrico-conical, the lower half or third 

 part enclosed in a hemispherical cup. 

 Main lateral nerves 6-12 pair, not prominent . 2. Q. Ilex. 

 Main lateral nerves 10-20 pair, prominent. 

 Leaves 4-8 in. long, rusty or tawny-tomentose 



beneath; main lateral nerves 10-16 pair 3. Q. lanuginosa. 

 Leaves 3-6 in. long, grey-tomentose beneath ; 



main lateral nerves 14-20 pair . . 4. Q. incana. 

 Full-grown leaves glabrous on both sides . . 5. Q. dilatata. 



Leaves deciduous in autumn ; styles short, thick, 

 clavate, and often lobed. 

 Leaves dentate, deeply lobed or pinnatifid ; main 

 lateral nerves 6-12 pair. 

 Leaves glabrous, short-petiolate, with auriculate 



base ; fruit pedunculate . . . . (6. Q. pedunculata. ) 

 Leaves pubescent beneath, narrowed into petiole ; 



fruit sessile (7. Q. sessili flora.) 



Leaves velvety beneath, pubescent above ; fruit 



short-pedunculate (8. Q. Toza.) 



Leaves dentate, main lateral nerves 10-14 pair . (9. Q. lusitanica.) 



