Naturalisation in Extra-Tropical Countries. 409 



Platanus racemosa, Nuttall. 



The Californian Plane-Tree. A good promenade-tree, which 

 according to Prof. Bolander grows more rapidly and more compact 

 than P. occidentalis. Wood harder and therefore more durable, also 

 less liable to warp. According to Dr. Gibbons, the tree attains a 

 height of about 100 feet and a stem-diameter of 8 feet. The wood 

 is brittle ; in use however by turners. 



Plectocomia Himalaiana, Griffiths. 



Sikkim, up to 7,000 feet, extending to 27 north latitude. This 

 Rattan-Palm requires moist forest-land. Its canes are not durable ; 

 but the plant is an object worthy of scenic horticulture, and would 

 prove the hardiest among its congeners. P. elongata (Blume) 

 ascends, according to Drude, to 4,500 feet. 



Plectocomia macrostachya, Kurz. 



Tenasserim, at about 3,000 feet elevation, therefore most likely 

 hardy in temperate lowlands. 



Plectranthus esculentus, N. E. Brown. 



Natal. A low underscrub, the tubers of which are eaten by the 

 natives and to a limited extent cultivated by them [J. M. Wood]. 

 These kinds of plants may become much improved under careful 

 cultivation. 



Plectranthus Madagascariensis, Bentham. 



Madagascar. This herb produces nutritious tubers [Mingard and 

 Daruty] . 



Plectronia ventosa, Linn& 



South- Africa. A hedge-bush, like P. ciliata (Sender) and P. spi- 

 nosa (Klotzsch). 



Plumbago Capensis, Thunberg. 



South- Africa. Quite a hedge-plant for small gardens, with the 

 particular value of bearing handsome blue flowers in autumn. P. 

 tristis (W. T. Aiton) is an allied species. 



Plumiera acutifolia, Poiret. 



Tropical America. A small, thick-branched tree, hardy at some 

 distance beyond the tropics. It is of such easy cultivation, that it 

 may become important, like many other as yet neglected apocynaceous 

 plants, for the scent of its large and copious flowers. 



Poa airoides, Koeler. (Catdbrosa aquatica, Beauvois.) 



The Water Whorl-grass. Europe, North-Africa, Northern and 

 Middle Asia, North- America. A creeping grass, suitable for pas- 

 tures subject to inundation ; hence fit also for irrigation. 



