1 82 BOTANY. 



in number to the lobes of the calyx, with which they alternate ; rarely 

 wanting. Stamens generally eight, inserted on a hypogynous disk. Ovary 

 tree, two-lobed, two-celled ; ovules in pairs ; amphitropal, pendulous ; style 

 one ; stigmas two. Fruit, a samara, composed of two winged carpels, each 

 o!ie-celled, with one to two seeds. Seeds erect, exalbuminous ; embryo 

 curved, with foliaceous cotyledons, and the radicle next the hilum. Trees 

 with opposite, simple, lobed or palmate, exstipulate leaves. Flowere often 

 l)olygamous. They are confined chiefly to the temperate parts of Europe, 

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

 is sometimes manufactured. 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 or break-wind in exposed places, as 

 near the sea. Its sap is slightly saccharine. Its wood is used in machinery 

 and lor charcoal. The leaves are often covered with black spots, caused 

 by the attack of a fungus, Xyloma or Rytisma acerinum. There are three 

 known genera, and sixty species. Examples : Acer, Negundo, Dobinea. 

 ( )f these genera, the two first with thirteen species are North American. 



Acer pseudo-platanus (Europe) {pi. 07, ßg. 1) ; «, a flowering branch ; 

 hy a male ; c*, female flower ; 6?, the winged fruit ; e, the seed. 



Order 182. MALPioniAcii.E, the Malpighia Family. Sepals five, slightly 

 united, persistent, often glandular at the base; aestivation imbricated, 

 l^etals five, unguiculate, with convolute aestivation. Stamens usually ten, 

 often monadelphous ; anthers roundish, with a projecting process from the 

 connective. Ovar}' formed by three (rarely two or four) carpels, more or 

 less combined ; ovules solitary, with a long pendulous cord ; styles three, 

 distinct or united. Fruit dry or fleshy, sometimes winged. Seeds solitary, 

 orthotropal, suspended, exalbuminous; embryo straight or curved in various 

 ways ; cotyledons foliaceous or thickish. 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 forty-two 

 genera, including 555 species. 



/Section A. Dijylosteviones. Number of stamens always double that of 

 petals, some of them occasionally sterile. Styles usually two to three. The 

 same number of ovaries united. Flowers of one form only. 



Tribe 1. Malpighiece. Fruit wingless. Example : Malpighia. 



Tribe 2. Banisteriecv. Carpels provided with wings, the dorsal solely or 

 most developed. Example : Lophopterys. 



Tribe 3. Hirmce. Carpels winged ; the marginal solely or most developed. 

 Example : Molina. 



Section B. Meiostetnones. The whole or part of the alternipetalous 

 stamens wanting. Style single by the abortion of two others. Ovaries 

 distinct. Flowers of two different forms on the same plant. 



Tribe 4. Gaudichaudiece. Carpels with or without wings. Example : 

 Gaudichaudia. 



182 



