KUTACE.E. 389 



ccnce, or indehiscent. Seeds few, usually with whitish albumen, 

 sometimes exalbuminous ; embryo green, with foliaceous cotyledons, 

 and a superior radicle. Herbs, shrubs, or trees, with opposite, stipu- 

 late, usually compound leaves, which are not dotted, and hermaphrodite 

 flowers. They occur in various parts of the world, chiefly in warm 

 extra-tropical regions, as in the south of Europe, America, Africa, 

 and India. The order has been divided into two sections: 1. Zygo- 

 phylleae, having albuminous seeds. 2. Tribuleaa, having exalbuminous 

 seeds. Lindley mentions 7 genera, comprising 100 species. Examples 

 Zygophyllum, Guaiacum, Tribulus. 



826. Some of the plants abound in a stimulant resin, which pervades 

 the wood and bark; others are bitter and acrid. The medicinal species 

 are used as sudorifics. Zygophyllum Fabago is called the Bean-caper, 

 on account of its flowers being used as a substitute for capers. The 

 plant is said to act as a vermifuge. Guaiacum officinale is a beautiful 

 West Indian tree, the wood of which, commonly called lignum-vitaa, 

 is prized for its hardness. The alburnum is of a greyish-yellow colour, 

 while the duramen is greenish-black. The fibres of the wood are 

 remarkable for their direction, being cross-grained, in consequence of 

 one layer crossing another diagonally. It yields a resinous matter 

 known as the resin of Guaiac, or Gum-guaiac. This resin exudes 

 spontaneously, or it may be procured by incisions, or by the applica- 

 tion of heat. A solution of the resin in alcohol, when applied to the 

 fresh cut surface of a potato, gives rise to a blue colour. Both the 

 wood and the resin are used medicinally on account of their stimulant 

 diaphoretic properties. In decoction and tincture they are adminis- 

 tered in cutaneous and syphilitic diseases. Guaiacum sanctum from 

 Mexico has similar properties, and is sometimes used medicinally on 

 the continent. 



827. Order 56. Rntaceze, the Rue Family. (Polypet. Hypog.) 

 See figs. 532, 533. Calyx having 4-5 segments, with an imbricated 

 aestivation. Petals alternate with the divisions of the calyx, distinct, 

 or cohering below into a spurious gamopetalous corolla, rarely want- 

 ing; aestivation either contorted or valvate. Stamens equal in number 

 to the petals, or twice or thrice as many (rarely fewer by abortion or 

 non-development) (fig. 534), usuaUy hypogynous, but in some instances 

 perigynous. Between the stamens and ovary there is a more or less 

 complete cup-shaped disk, which is either free or united to the calyx. 

 Ovary sessile or supported on a gynophore (fig. 382), its carpels equal 

 to the petals in number or fewer; ovules 2, rarely 4 or fewer in each 

 carpel; styles adherent above (fig. 382); stigma simple or dilated. 

 Fruit capsular, its parts either combined completely or partially; seeds 

 solitary or in pairs, albuminous or exalbuminous ; embryo with a 

 superior radicle. Trees or shrubs, with exstipulate, opposite or 

 alternate leaves, usually covered with pellucid resinous dots (figs. 87, 



