838 The Trees of Great Britain and Ireland 



Fruit, ripening in one season, one to three nuts, ovoid, plano-convex or com- 

 pressed, enclosed in an involucre, which is tomentose within and is covered externally 

 with branched spines fascicled between deciduous scales, the nuts escaping by the 

 ultimate splitting of the involucre above into two to four valves. Nut crowned by 

 the styles, marked with a scar at the base, its shell lined with tomentum. Seed 

 usually solitary, occasionally two to three in each nut, the aborted ovules, two to 

 eleven in number, remaining at the apex of the seed. Albumen absent. Cotyledons 

 thick, fleshy, undulate, sweet, farinaceous, remaining under ground on germination. 



The genus ' is confined to the warmer parts of the northern temperate zone, and 

 much difference of opinion exists as to the various forms 2 which are met with. 

 Formerly only two species were recognised, viz. C. sativa and C. pumila ; but the 

 former, widely spread over North America, Europe, and Asia, exists in certain well- 

 marked geographical forms, which it is convenient to treat as distinct species. A 

 small shrub, occurring in North America, near the coast in the South Atlantic states 

 and in Louisiana and Arkansas, is considered by American botanists to be another 

 distinct species, Castanea alnifolia, Nuttall, and will not be further alluded to. 

 Four species have been introduced into cultivation and are distinguished as 

 follows : 



I. Leaves without stellate tomentum, acute at the base. 



1. Castanea dentata, Borkhausen. N. America. See p. 856. 



Leaves tapering at the base, long acuminate at the apex, green and glabrous 

 beneath, pendulous. Petiole glabrous. 



II. Leaves with stellate tomentum, rounded or cordate at the base. 



2. Castanea sativa, Miller. Europe, N. Africa, Asia Minor, Caucasus, Persia. 



See p. 839. 

 Leaves green beneath, always showing some trace at least of tomentum, 

 not pendulous, coarsely serrate. Petiole and young shoots scurfy pubescent. 



3. Castanea crenata, Siebold et Zuccarini. China, Japan. See p. 854. 



Leaves green beneath, tomentum variable in quantity, shallowly and 

 crenately serrate, the teeth often reduced to bristle-like points. Petiole, young 

 shoots, and midrib densely pubescent with short hairs. 



4. Castanea pumila, Miller. N. America. See p. 857. 



Leaves silvery white and always tomentose beneath. Petiole and young 

 shoots strongly pubescent. 



1 In Castanea, the leaves are deciduous, no terminal bud is formed, and the fruits ripen in one season. In Caslanopsis 

 the leaves are persistent, a terminal bud is present, and the fruits ripen at the end of the second season. 



1 Dode enumerates twelve species, some of which are alluded to in our accounts of C. crenata and C. pumila. 



