PLATE 9. 
CHEIRANTHUS ALPINUS. 
(Erysimum ochroleucum). 
The genus Erysimum is so closely related to Cheiranthus that it is no 
wonder the two have become much confused. This is unfortunate in many 
ways, especially in connection with garden plants, for once a name becomes 
established—no matter how inaccurate it may be from a purely scientific point 
of view—it clings to a plant with the utmost tenacity. Hence the plant now 
figured would be more accurately described as an Erysimum. 
There are many species of Erysimum, but very few are of any ornamental 
value. Of these, the handsome subject of the coloured plate is certainly the 
best and most useful for garden purposes. It is found spread over the 
Pyrenees and Alps from Spain to Transsylvania, growing in rocky places. 
With such a wide distribution, it naturally follows that there are several forms 
of this plant, varying in height from three to eighteen inches. Some of the 
taller forms are weedy in habit and scarcely worth growing, but the form 
figured and more generally known as Cheiranthus alpinus, is dwarf and compact. 
Its beautiful sulphur coloured flowers of good size are very freely produced, and 
the plant remains in full beauty for a considerable period, rendering it eminently 
suitable for growing on sunny ledges, or in pockets in the rock garden. 
E. ochroleucum in its various forms has been in cultivation for a long 
time, but the present plant was introduced as Cheiranthus ochroleucus in 
the year 1819 from the Alps. The name Cheiranthus alpinus has been applied 
to five different plants of the genus Erysimum, the true C. alpinus of Linnaeus 
being a native of Lapland and Norway. The latter plant I have not seen in 
cultivation and as there does not seem to be any specimen of this in the Kew 
Herbarium it probably never has been introduced, all the plants bearing the 
name belonging to other species. 
E. ochroleucum is a most ornamental plant, forming compact tufts from 
6in. to 9in. high, and is of very easy cultivation. It will thrive in the 
herbaceous border, although liable to get killed by wet in the winter. Cuttings 
root readily, and the plant may also be increased by division of the root. 
E. ochroleucum var. helveticum (syn. E. rhceticum) is a somewhat taller 
plant of less compact habit and narrower leaves. 
There are two or three other species well worth a place in the rock 
garden including E. rupestre (pulchellum) from Asia Minor. It forms a low 
carpet and thrives well in gritty soil and enjoys a sunny position. It is similar 
in appearance to E. ochroleucum but smaller in foliage and flower. E. 
pumilum is a very small growing plant from the Alps, often but one or two 
inches high, with yellow flowers, large in comparison to the plant. It thrives 
best in poor well-drained soil, as also does the Armenian E. purpureum, a little 
gem with purple flowers on plants no larger than those of the preceding- 
species. Of the annual members of the genus the well known E. perov- 
skianum is by far the best, with its orange yellow flowers. W. Irving. 
