204 XXXV. AURANTIACE^. Citrus. 



Order XXXIV. RUTACE^.— Rueworts. 



Herbs, or generally shrubs and trees, with punctate Ivs. and no stipules. 



Fis. perfect. Sep. 4— 5. P«r. 4— 5, rarely 0. ,, j- i. 



Sla. as many, or twice or thrice as many as petals, inserted on the outside of a cup-like disk. 



Ova. 3— 5-lobed, 3— 5-celled ; styles united or distinct only at base. 



Fr. usually separating into its component, few-seeded carpels. 



Genera 47, species 400, usually inhabiting the warmer parts of the temperate zone on the Eastern con- 

 tinent, and the equatorial parts of S. America. They are characterized by a powerful odor and intense 

 bitterness, often febrifugal and anthelmintic. Dictamnus abounds in a volatile oil, dittusing an inflam- 

 mable gas. 



Gc7icra. 



Sepals permanent. Petals equal Ruta. l 



Sepals deciduous. Petals unequal DMamnw. 2 



1. RUTA. 



Calyx of 4 — 5 sepals united at base ; petals 4 — 5, concave, obo- 



vate, distinct; torus surrounded by 10 nectariferous pores; stamens 



10; capsule lobed. — % Herbaceous or shrubby^ mostly European. 



R. GRAVEOLENs. Common Rue. — SujfFiuticose, nearly glabrous ; Ivs. 2 and 3- 

 pinnately divided, segments oblong, obtuse, terminal ones obovate-cuneate, all 

 entire or irregularly cleft; fls. terminal, corymbose ; fet. entire. — Native of S. 

 Europe. Stem branched, 3 — 4f high. Leaflets 6—10" by 2—4", conspicuously 

 dotted. Corolla yellow, 6" diam. Jn. — Sept, \ 



2. DICTAMNUS. 

 Calyx of 5 deciduous sepals ; petals 5, unguiculate, unequal ; fila- 

 ments declinate, with glandular dots; capsules 5, slightly united. — % 

 Herbs^ native of Germany. 



D. ALBUs.- Willd. (and D. Fraxinella. Link.) F.raxinella.—St. simple; 

 Ivs. pinnate, the rachis more or less winged ; fis. in a large, terminal, erect pan- 

 icle. — In gardens. Stems 1 — 2f high. Flowers sho-«y, white, varying to rose- 

 color and purple. The whole plant emits a lemon-scented, aromatic, volatile 

 oil, which is so abundant in hot weather as to render the air around it inflam- 

 mable, t 



/?. rubra. Flowers purple ; rachis of the leaves winged, f 



Order XXXV. AURANTIACE^.— Oranges. 



Trees ox shrubs, glabrous, abounding in little transparent receptacles of volatile oil. 



Lv8. alternate, articulated with the petiole which is frequently winged. 



Cai.— Sepals 3—5, united into a short, urceolate or campanulate cup. 



Cor.— Petals 3—5. 



Sta. as many as the petals, or some multiple of their number, in a single row, hypogynous. 



Ova. compounded of several united carpels. Style 1. 



JFV. — A berry (orange), many-celled, pulpy, covered with a thick rind. 



Sds. attached to the inner angle of each carpel. Albumen 0. 



Genera 20, species 95, nearly all natives of tropical Asia, and are naturalized throughout all tropical 

 regions, and cultivated in all civilized countries for their beauty and fragrance, both of flowers and fruit. 



Proper?!^?.— These fruits contain free citric and malic acid, and their pulp is grateful to the taste. 

 The rind contains an aromatic, volatile oil, which i.s tonic and stomachic. The rind of the lime yields 

 the oil of Bergamot, and the flower of the orange the oil of Neroli. 



CITRUS. 



Gr, Kirpia, the citron ; the fruit of one of the species. 



Sepals and petals in 5s ; anthers 20, or some other and higher 

 multiple of 5, versatile, the connectile articulated to the filament ; 

 filaments dilated at base, polyadelphous ; berry 9 — 18-celled. — A no- 

 ble genus of trees and shrubs, all tropical, combining in its species, beauty 

 of form, loith shining, ever-green foliage, odoriferous flowers, an/1 fragrant 

 and delicious fruit. 



1, C, LiMovuM, Lemon Tree.— Petioles somewhat winged, articulated with 

 the lamina (which is thus shown to be the terminal or odd leaflet of a reduced 



