458 ACEKACE^ — SAPINDACB^. 



Flowers either perfect or unisexual. They are inhabitants of tropical 

 countries chiefly, and a great number of them are found in South 

 America. Authors notice 50 genera, including 589 species. Examples 

 — Malpighia, Banisteria, Hiptage, Hirsea, Gaudichaudia. 



Some of the woody plants of this order exhibit an anomalous for- 

 mation of the stem, from the absence of annular rings and medullary 

 rays, and the peculiar mode in which the bark is produced. This is 

 shown in figs. 123, p. 61 ; 126, and 127, p. 62. Many of the 

 plants are astringent. Some have stinging hairs (fig. 89, p. 33). 

 The fruit of Malpighia glabra and of M. pnnicifolia is called Barbados 

 Cherry, and is used as an article of dessert. Nitraria is a genus doubt- 

 fully referred to this order ; by some it is placed imder the order 

 Zygophyllacem. N. tridentata, found in the desert of Soussa, near Tunis, 

 is said by some to be the true Lotus-tree of the ancient Lotophagi. 



Order 39. — AcEEACEiE, the Maple Family. (Polypet. Eypog.) 

 Calyx divided into 5, rarely into 4 or 9 parts, with an imbricated 

 sestivation. Petals equal in number to the lobes of the calyx, with 

 which they alternate, rarely wanting. Stamens generally 8, inserted 

 on a hypogynous disk. Ovary free, 2-lobed, 2-celled ; ovules in pairs ; 

 amphitropal, pendulous ; style 1 ; stigmas 2. Fruit, a samara (fig. 

 561, p. 310), composed of two winged carpels, each 1-celled with 1-2 

 seeds. Seeds erect, exalbuminous ; embryo curved, with foliaceous 

 cotyledons, and the radicle next the hUum. — Trees with opposite, 

 simple, lobed or palmate, exstipulate leaves. Flowers often polyga- 

 mous. They are confined chiefly to the temperate parts of Europe, 

 Asia, and North America. They yield a saccharine sap, from which 

 sugar is sometimes manufactured. It is said that their juices become 

 acrid as the season advances. The bark is astringent, and yields 

 reddish-brown and yeUow-coloured dyes. Acer saccharinum is the 

 Sugar Maple of America. Acer Pseudo-platanus, the Sycamore or 

 Great Maple (the Plane-tree of Scotland), acts well as a shelter in 

 exposed places, as near the sea. Its sap is slightly saccharine. Its 

 wood is used in machinery and for charcoal. The leaves are often 

 covered with black spots, caused by the attack of a fungus, Khytisma 

 acerinum. There are 3 known genera, and 60 species. Examples — 

 Acer, Negundo, Dobinea. 



Order 40. — SAPiNDACE.a!, the Soapwort Family. (Polypet. Eypog.) 

 Sepals 4-5, distinct or cohering at the base ; sestivation imbricated. 

 Petals 4-5, occasionally absent, hypogynous, sometimes naked, some- 

 times with a glandular or scaly appendage inside ; sestivation imbri- 

 cated. Stamens usually 8-10, sometimes 5-6-7, very rarely 20 ; fila- 

 ments free, or combined just at the base ; anthers introrse. Thala- 

 mus forming a fleshy or glandular disc, into which the stamens are 

 often inserted. Ovary trUocular, rarely bi- or quadri-locular ; ovules 

 anatropal, definite ; style either undivided or 2-3 cleft. Fruit either 



