CHAP, XXX. XANTHOXYLA CEE. - 487 
App. i. Half-hardy Species of Ruta. 
The following species of Rita are generally kept in the frame or green-house ; but there is little 
doubt that they would live in very dry soil or in lime rubbish, at the base of a wall, with some pro- 
tection during severe weather. R&. ape L. (Bot. Reg., t. 307.), a native of the Canary Islands, 
where it grows to the height of 6 ft.; 2. bractedsa Dec., a shrub 2 ft. high, a native of Sicily; #. 
angustifolia Pers. (fig. 156.), a native of the south of France, which was 
considered by Linnzus and others as a variety of the common rue; 
R. macrophflla Sol., from the north of Africa, where it grows 3 ft. 
high ; 2. montana Clus., from the south of Europe, also growing 3 ft. 
high ; 2. divaricata Tenore, from the south of Italy ; R. cérsica Dec., 
from Corsica; R. albiflora [Hook., from Nepal, which was introduced 
in 1823, and which is found in the Himalayas, at elevations of trom 
500 ft. to 800 ft. ; together with some other species from Nepal, from the 
south of Europe, and from the north of Africa; might all, we think, be 
tried at the base of a conservative wall, with every prospect of success. 
Perhaps half or more of the sorts above enumerated are only varieties 
of Ruta gravéolens, but the shrubis so truly beautiful in the form and 
colour of its foliage, in its neat and compact shape, and its numerous 
flowers, that every variety is well worth cultivating. 
Genus II. 
APLOPHY’LLUM Andr. Juss. Tut APLOPHYLUUM, or SIMPLE-LEAVED 
Rue. Lin. Syst. Decndria MonogYnia, 
This genus, which forms a section of Rita in De Candolle’s Prodromus, 
was instituted by A. Jussieu in Mém. Mus., 12. p. 464., and is adopted by G. 
Don. It contains two or three species of small undershrubs, which are 
han? but which are more frequently treated as herbaceous than as Jigneous 
plants. 
” 1. A. linifdlium G. Don., Rita linifdlia L., (Bot. Rep., 565.,and our 
fig. 157.) has entire oblong-lanceolate leaves, and yellow flowers in corymbs. 
It is a native of Spain, near Valencia, and also of Greece. It was introduced 
in 1752, grows to about 1 ft. in height, and flowers from July to September. 
2 2. A. suaveolens G. Don., Rita suaveolens Dec., has spathulately lance- 
olate glaucous leaves, and yellow flowers in corymbs, smelling like those of A &x 
Primula officinalis. It is a native of Tauria, where it forms a shrub about 2 > 
2 ft. high ; and was introduced in 1800. It flowers from June to September. 
® 3. A. fruticuldsum G. Don, Rita fruticuldsa Lab., is a native of the 
country about Damascus. It grows about 1 ft. high, but has not yet been in- 
troduced into Britain, 
CHAP. XXX. 
OF THE HARDY AND HALF-HARDY LIGNEOUS PLANTS OF THE 
ORDER XANTHOXYLA‘CEX. 
Tur genera belonging to this order which contain hardy species are three, 
Xanthdxylum, Ptélea, and Ailéntus, which are thus distinguished in Don’s 
Mill., i. p. 777. 
Xanrno’xyium L., and H. et Kth. Flowers bisexual. Calyx 3—5-parted, 
with an equal number of petals and stamens. Carpels 1—5, 2-valved. 
Leaves simple, ternate, abruptly and impari-pinnate. 
Pre'.ea L. Flowers bisexual. Calyx 4—5-parted. Petals 4—5. Sta- 
mens 4—5. Fruit compressed, 2—3-celled ; cells 1-seeded, turgid in the 
centre, each cell extended into an orbicular reticulated wing. Leaves of 3 
leaflets, rarely of 5 leaflets. 
AILANTUs Desf. Flowers polygamous. Calyx 5-cleft. Petals 5. Stamens 
10, unequal. Styles 3—5, arising from the notches of the ovaries. Carpels 
3—5, membraneous, I-celled, 1-seeded. Leaves abruptly or impari- 
pinnate, 
