VASCULAR PLANTS. 119 



a nut (akene), the base of which is surrounded 

 by a cupula (persistent involucre). 



1. Quercus, L 



Monoecious. Aments slender. 8 perigo- 

 nium 4 — 8-parted: ? 6-dentate. Style short; 

 stigmas 3. Ovary 3-locuiar, 6-ovulate, sur- 

 rounded by a scaly, bud-like involucre, which 

 in fruit enlarges into a cup surrounding the 

 base of the nut. £ . 



2. Castanopsis, Spach. 



Monoecious. Aments slender, panicled on 

 the young shoots. $ perigonium 5-lobed; 

 stamens 10. ? flowers 1 — 3, in a scaly invol- 

 ucre, sessile at the base of the ament; perigo- 

 nium 6-lobed, 2-seriate; fruit 1 — 3 nuts entirely 

 enclosed in a prickly, irregularly rupturing in- 

 volucre. ^ . 



3. Corylus. Tournef. 



Monoecious. Aments slender. Scales (bracts) 

 imbricated. $ flowers, besides the scales, 2- 

 bracteolate. Stamens 8; anthers 1-locular. 9 

 flowers immersed into a bud; uppermost 

 scales containing flowers, the rest empty. Ovary 

 2-bracteolate, crowned by a minute perigoirium, 

 2-locular; stigmas 2. Fruit a nut surrounded by 

 a large incised involucre, formed by the growth 

 of the 2-bractlets. ^ . 



