

in Extra-Tropical Countries. 319 



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 Wislizenii, A. de Candolle. 



Mexico, at an elevation of about 7,000 feet, also reaching California. 

 A magnificent tree with dense foliage, the stem attaining finally a 

 circumference of 18 feet (Prof. Sargent). 



Quercus Xalcepensis, 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 Finck). 



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. 



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. 



Raphanus sativus, Linn<5. 



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

 to 16,000 feet, eastward to Japan. In Norway it can be grown north- 

 ward to lat. 70 22' (Prof. Schuebeler). R. caudatus, L., the radish 

 with long edible pods, is regarded by Dr. Th. Anderson as a mere 

 variety, and he thinks, that all are sprung from the ordinary R. 

 Raphanistrum, L., of Europe. All radishes succeed best in a cal- 

 careous soil, or their culture must be aided by manure rich in lime. 

 The root of the black radish is comparatively rich in starch. The 

 seeds, according to Vilmorin, will keep about five years. 



Remirea maritima, Aublet. 



Intra-tropical coast-regions around the globe. A perennial creeping 

 sedge for binding sand. 



Reseda Luteola, Linn. 



The Weld. Middle and Southern Europe, Middle Asia, North- 

 Africa. An herb of one or two years' duration. Likes calcareous 

 soil. A yellow dye (luteolin) pervades the whole plant. The plant 

 must be cut before the fruit commences to develop, otherwise the 

 pigment will much diminish. 



