CHAP. XXX. 



XANTHOXYLA CEJE. 



487 



App. i. Half-hardy Species ofRuta. 



The following species of Rhta are generally kept in the frame or green.house ; but there is little 

 doubt that they would live in verv dry soil or in lime rubbish, at the base of a wall, with some pro- 

 tection during severe weather. B. pinnata L. [Bot. Reg., t. .JOT.), a native of the Canary Islands, 

 where it grows to the height of (5 ft. ; IL bractebsa D<c., a slirub 2 ft. high, a native of Sicily ; It. 

 angustif;.lia Pcrs. {fiff. ISli.), a native of the south of France, which was 

 considered by Linna;us and others as a variety of the common rue; 

 J{. macrophylla Sol., from the north of Africa, where it grows :> ft. 

 high ; R. mbnt;\na C/us., from the south of Europe, also growing 3 ft. 

 high ; R. divaricata Tenore, from the south of Italy; R. Corsica Dec, 

 from Corsica; R. albiflira Houk., 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 tlie 

 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 Rixta. gravenlcns, but the shrub is 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. The Aplophvllum, or SnfPLE-LF.AfED 



Rue. Lin. Sj/st. Decandria Monogjnia. 



This genus, which forms a section of .Rfita in De Candolle's Prorfron??*^, 

 was instituted by A. Jussieu in M^m. M7is., 12. p. 464., and is adopted by G. 

 Don. It contains two or three species of small under.-hrubs, which are 

 hardy, but which are more frequently treated as herbaceous than as ligneous 

 plants. 



a. 1. A. hnifhlium G. Don., i?uta /inifWia L., [Rot. Rep., 565., and our 

 fig. 157.) has entire oblong-lanceolate leaves, and vellow 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. 



a. 2. A. snaviolens G. Don., Riila. suavfeolens Dec, has spathulately lance- 

 olate glaucous leaves, and vellow flowers in corymbs, smelling like those of 

 Prfmula officinalis. It is a' native of Tauria, where it forms a shrub about 

 2 ft. high ; and was introduced in ISOU. It flowers from June to September. 



e. 3. A. fruliculdsum G. Don, 7/ilta fruticulbsa Lab., is a native of the 

 country about Damascus. It grows about 1 ft. high, but has not yet been in- 

 troduced into Britain. 



157 



CHAP. XXX. 



OF THE HARDY AND HALF-HARDY LIGNEOUS PLANTS OF THE 

 ORDER XANTHOXYLA'CEjE. 



The (^enera belonging to this order which contain hardy species are three, 



Xanthoxylum, Ptelea, and Ailantus, which arc thus distinguished in Don's 



Mill., i. p. 777. 



Xantho'xylum L., and H. ct Klh. Flowers bisexual. Calyx 3— 5-partcd, 

 with an equal number of petals and stamens. Carpels 1—5, 2-valved, 

 Leaves simple, ternate, abruptly and impari-pinnate. 



Ptelea 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. 



AlLA'NTUsT>C'A'i. Flowers polygamous. Calyx 5-cleft. Petals 5. Stamens 

 10, unequal. Styles 3—5, arising from the notches of the ovaries. Carpels 

 3—5, membraneous, 1-celled, 1-seeded. Leaves abruptly or impari- 

 pinnate. 



