_ (Black Poplar), and _P. tremula_.

POTENTILLA FRUTICOSA* (Shrubby Cinquefoil).--Well deserves more
attention.

PRUNUS.--Of these, the Cherry and Bird Cherry,* Plum,* Bullace,* and the
beautiful _P. triloba_ are a success.

PTELEA TRIFOLIATA.

PYRUS.--_P. Aria_* (the White Beam tree), _P. Aucuparia_* (Mountain
Ash), _P. japonica_,* _P. rotundifolia_,* _P. Sorbus_* (Service tree).

QUERCUS (Oak).--The most satisfactory species are _Q. sessilifolia_,*
and _Q. pedunculata_. These generally thrive well and are amongst the
most beautiful of trees for large gardens. In poor soil and windswept
places the British Oaks do not grow more than about 40 feet in height,
but develop into picturesque features. Their foliage here is of a
pleasing green when that of the Beech and Sycamore is past its best.
Very few acorns are produced. _Q. Cerris_,* the Turkey Oak, and its
variety _laciniata_,* and _Q. lucombeana_,* are also beautiful trees. We
must also mention the Evergreen Oak (_Q. Ilex_),* _alba_, _palustris_,
_laurifolia_, _coccinea_ (Scarlet Oak), _Suber_ (Cork Oak), _conferta_.

RHODODENDRON.--Of the Rhododendrons the following are satisfactory: _R.
altaclerense_, _Anthopogon_, _arborescens_, _arboreum Campbelliae_,
_azaleoides_, _blandyanum_, _calendulaceum_, _campanulatum_,
_campylocarpum_, _catawbiense_, _caucasicum_,* _ciliatum_,
_cinnabarinum_,* _ferrugineum_,* _fulgens_, _glaucum_,* _hirsutum_* and
varieties, _indicum balsaminaeflorum_, _lancifolium_, _lepidotum_,*
_myrtifolium_,* _nobleanum_,* _n. album_,* _ponticum_* (many varieties),
_praecox_,* _punctatum_, _racemosum_, _Rhodora_, _sinensis_* (_Azalea
mollis_), _Vaseyi_,* _Wilsoni_. These are the principal Rhododendrons
that thrive and flower well here. No other shrubs give such a long and
varied flower display.

RIBES.--_R. alpinum_, _aureum_, and _rubrum_. _R. sanguineum_* and its
varieties are the principal ornamental currants.

ROBINIA PSEUDACACIA.*--An elegant foliage tree, and usually the last to
break into leaf.

ROSA.--Practically all the Tea and Hybrid Perpetual Roses can be grown,
if sheltered spots are chosen and the plants grown as dwarfs. However,
the stronger varieties are the most satisfactory ones, and in bad
seasons it is July before they commence to flower, although September
has well advanced before they cease. The hybrid Sweet Briars are the
freest of all to grow. Groups form thickets of foliage which are almost
hidden with blossom. _Rosa