ACERACE^E SAPINDACE.E. 381 



formed by 3 (rarely 2 or 4) carpels, more or less combined ; ovules 

 solitary, with a long pendulous cord; styles 3, distinct or united. 

 Fruit dry or fleshy, sometimes winged (fig. 466). Seeds solitary, 

 orthotropal, suspended, exalbuminous ; embryo straight or curved in 

 various ways ; cotyledons foliaceous or thickish (fig. 506). Trees or 

 shrubs, sometimes climbing, with simple, opposite, or very rarely 

 alternate, stipulate leaves, without dots. Hairs, when present, peltate. 

 Flowers either perfect or unisexual. They are inhabitants of tropical 

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

 America. Lindley notices 42 genera, including 555 species. Exam- 

 ples Malpighia, Banisteria, Hiptage, Hiraea, Gaudichaudia. 



804. Some of the woody plants of this order exhibit an anomalous 

 formation 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. 105, 108, and 109. Many of the plants are astringent. 

 Some have stinging hairs (fig. 84). The fruit of Malpighia glabra is 

 called Barbadoes Cherry, and is used as an article of dessert. Nitraria 

 is a genus doubtfully referred to this order. N. tridentata, found in 

 the desert of Soussa, near Tunis, is said by some to be the true Lotus- 

 tree of the ancient Lotophagi. 



805. Order 42. Acemcete, the Maple. Family. (Polypet. Hypog.) 

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

 vation. 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. 

 465), composed of two winged carpels, each 1-celled with 1-2 seeds. 

 Seeds erect, exalbuminous; embryo curved, with foliaceous cotyle- 

 dons, and the radicle next the hilum. Trees with opposite, simple, 

 lobed or palmate, exstipulate leaves. Flowers often polygamous. 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. Acer saccharinum is the Sugar Maple of America. 

 Acer Pseudo-platamis, the Sycamore or Great Maple (the Plane-tree 

 of Scotland), acts weU 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, Xyloma or Rytisma acerinum. There are 3 

 known genera, and 60 species. Examples Acer, Negundo, Dobinea. 



806. Order 43. Sapindacete, the Soapwort Family. (Polypet Hy- 

 pog). Sepals 4-5, distinct or cohering at the base; aestivation imbri- 

 cated. Petals 4-5, occasionally absent, hypogynous, sometimes naked, 

 sometimes with a glandular or scaly appendage inside ; aestivation 

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

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



