This grand old tree belongs to the genus Quercus, and pedunculata is generally given as the species; it is, however, a form of Robur with stalked cups; there are several sub-varieties, such as Concordia, fastigiata (pyramidal), silver variegated, pectinata, asplenifolia, purpurascens, pendula, leucocarpa (yellow) and heterophylla. The stalkless form of Robur is called sessiliflora. These are the giant Oaks of the great parks. Cerris, the Turkey Oak, is a somewhat smaller but still large tree; rubra is the Red Oak; there is a beautiful variety called aurea. There is a silver-variegated form of Cerris among several others. Lucombe's Oak is a sub-evergreen. Other species of medium size are coccinea, the North American Scarlet Oak, which has beautiful colour in autumn (Waterer's variety, or Knap Hill Scarlet is good); conferta (syn. pannonica) the Hungarian Oak, a handsome, deeply-lobed species of very quick growth; palustris, the Pin or Marsh Oak, another North American species with fine colour in the fall; macrocarpa, the Burr Oak; Mirbeckii (syn. Zang) a very handsome species; and heterophylla, narrow-leaved. The common evergreen Oak (also known as Holm Oak and Holly Oak) is Q. Ilex, a useful hardy but rather dull tree. There are, however, several other good evergreen species, such as acuta and serrata, both small species from Japan; cuspidata and its variegated form; and glabra. Other species are Phellos, the Willow Oak, with long, narrow leaves; Suber, the Cork Oak, which gives the commercial cork; and Prinus, the Chestnut Oak. The Evergreen and Turkey Oaks are good seaside trees and the former thrives in towns. Deep loamy soil.