568 
RUTACEAE 
trop. and temp., esp. S. Afr. and Austr. Most are shrubs and trees, 
often xerophytic and frequently of heath-like habit (e.g. Diosma). 
Leaves alt. or opp., exstip., usually compound, with glandular dots, 
often aromatic. In many Aurantieae there are short shoots whose 
leaves are reduced to thorns (cf. Cactaceae). Infl. of various forms, 
usually cymose. Fir. g , rarely unisexual, regular or zygomorphic, 
5 — 4-merous (see Ruta), with a large disc below the gynoeceum. 
K 5 or 4, the odd sepal posterior; C 5 or 4, imbricate; A 10 or 8, 
obdiplostemonous, or 5, 3, 2, or 00, with introrse anthers; G (5 or 4), 
rarely (3 — 1) or (00 ), often free at base and united above by the style 
(cf. Apocynaceae), multiloc.; ovules 2 — 00 in each loc., anatropous 
with ventral raphe and micropyle facing upwards. Fruit various; 
schizocarps, drupes, berries, &c. Seeds with or without endosperm. 
A 
B 
Floral diagrams of Rutaceae, after Eichler. A, Ruta graveolens (d=disc) ; B, Citrus 
Aurantium , single case showing variable numbers in stamen-bundles. 
Several R. are or have been used in medicine, chiefly on account 
of the oils they contain, e.g. Ruta, Galipea, Toddalia, &c. Citrus 
yields important fruits, and Chloroxylon a dye-stuff. 
Classification and chief genera (after Engler) : The groups of R. 
differ considerably among themselves, and several of them were 
formerly regarded as independent orders. The relationships to allied 
orders are thus given by Engler : 
Zygophyllaceae 
Cneoraceae 
f Meliaceae 
Burseraceae 
| tSimarubaceae 
Rutaceae 
The characters of the chief sub-orders only are given here. 
RLJTOIDEAE. Cpls. usually 4 — 5, rarely 3 — 1, or more than 
5, often only united by the style, and ± divided when ripe; loculicidal 
dehiscence usually with separation of the endocarp ; rarely 4 — 1 fleshy 
drupes. 
I. Zanthoxyleae (woody plants, usually with small greenish, 
regular, often unisexual firs. ; cpl. rarely with > 2 ovules; embryo 
with flat cotyledons in endosperm) : Zanthoxylum, Fagara, Choisya. 
