Naturalisation in Extra-Tropical Countries. 455 



Quercus virens, Linn&* 



The Live-Oak of North-America, extending northward only to 

 Virginia, occurring also in Mexico. One of the hardiest of the 

 evergreen species, and among congeners in the United States the 

 quickest in growth [Fernow]. Likes a coast-climate and a soil rich 

 in mould. Becomes 60 feet high, with a stem sometimes to 9 feet 

 in diameter. Supplies a most valuable timber for ship-building ; 

 it is heavj, compact, fine-grained ; it is moreover the strongest and 

 most durable yielded by any American oaks. Like Q. stellata, it 

 lives also on sea-shores, helping to bind the sand, but it is then not 

 of tall stature. Q. Virginiana (Miller) is the oldest name for this 

 oak as pointed out by C. Koch. Of many of the 300 oaks occurring 

 in the western and eastern portions of the northern hemisphere, the 

 properties remain unrecorded and perhaps unexamined ; but it would 

 be important to introduce as many kinds as possible for local test- 

 growth. 



Quercus ^Tislizenii, A. de Candolle. 



California, at an elevation of about 7,000 feet, extending to Shasta. 

 Allied to Q. agrifolia. A magnificent tree with dense foliage, the 

 stem attaining finally a circumference of 18 feet [Prof. Sargent]. 

 Wood hard, tough, and durable [Prof. Green]. 



Quercus Xalospensis, Humboldt and Bonpland. 



Mexico, ascending to 5,000 feet, preferring for localities poor soil, 

 but of ferruginous clay, where little else will grow. Height to 80 feet; 

 it is a quick grower ; its timber will endure only under roof ; the 

 tree gives a heavy crop of acorns [Hugo Fink]. The nearly allied 

 Q. commutata attains 70 feet and ascends to 1 1,000 feet [Liebmann]. 



Quillaja saponaria, Molina. 



Chili. A colossal tree, fit not only for loamy but also sandy and 

 peaty soil. The bark is rich in saponin, and therefore valuable for 

 dressing wool and silk, also for various cleansing processes. Kage- 

 neckia oblonga (Ruiz and Pavon) is allied, and from the same country, 

 extending to Peru, and provides locally tan-bark [Dr. J. A. de los 

 Rios]. 



Rafnia amplexicaulis, Thunberg. 



South-Africa. The root of this bush is sweet like liquorice, and is 

 administered in medicine. Rafnia perfoliata (E. Meyer), also from 

 South-Africa, furnishes likewise a medicinal root. 



Baphanus sativus, Linn. 



The Radish. Temperate Asia, southward to the Himalayas up to 

 16,000 feet, eastward to Japan. Cultivated already by the ancient 

 Romans and Greeks. Ripens seeds quite well even in the hot desert- 

 tracts of Central Australia. Can in mild climes be grown all the 



