866 LXX. HIPPOCASTANEiE. 



fleshy. Embeto exalbuminous ; cotyledons foliaceous, green, accumbent, irregularly 

 folded or convolute ; radicle descending, facing the hilum. 



GENEEA. 

 Acer. Kegundo. Dobinea. 



AcerinecE, regarded bj' Bentham and Hooker fil. as a sub-order of Sapindacece (see p. 353), only differ 

 from tbese in their always opposite leaves and non-appendiculate petals, and in their occasionally trimerous 

 fruit (Acer pseudo-Platamts) , as in most Sapindacece. Hippocastanea only differ from Acerinece in their capsvde 

 with semi-septiferous valves ; and are further allied, since in both orders the buds bear both leaves and 

 flowers. For the affinity with Malpighiacece see p. 301. 



Acerine(S inhabit northern temperate regions, and especially Japan, the Himalayas, and eastern North 

 America. The curious genus Dohinea, which is placed in Acerinece, is Plimalayan ; [it has apetalous ? 

 flowers -without a disk, and a one-celled ovary, which ripens into a small broadly-winged achene. — Ed.]. 



Acerinece contain a sugary sap, milky in some, limpid in others, which is obtained by incision of the 

 trunk, and is either evaporated for sugar (the Maple Sugar of Canada), or allowed to ferment and thus 

 form spirituous or acid liquors. Their bark is astringent, and yields reddish or yellow colouring principles. 

 [The wood of various species is of great value, especially the Bird's-eye Maple of America. — Ed.] 



LXX. HIPPOCASTANEyE,"- Endlicher. 



Large or small teees with scaly buds. Leaves opposite |^alternate in 

 Ungnadia. — Ed. J, generally digitate, rarely imparipinnate, with toothed or crenate 

 leaflets ; stipules 0. Flowees ^ or polygainous, in racemes or terminal thyrsi. 

 Calyx campanulate or tubular, 5-fid, lobes unequal, imbricate. Petals 4-6, 

 inserted on the receptacle, unequal, clawed, not appendiculate, imbricate. Disk 

 hypogynous, entire, annular or unilateral. Stamens 5-8, usually 7, inserted within 

 the disk, and free ; filaments filiform, exserted, ascending ; anthers 2-celled, dehiscence 

 longitudinal. Ovaet sessile, oblong or lanceolate, of 3 2-ovuled cells ; style conical 

 or filiform ; stign%a pointed ; ovules curved, fixed to the central angle of the cell, 

 superimposed or horizontal, or one ascending, the other pendulous. Capsule coria- 

 ceous, naked or spinous, 3-eelled or 2-1 -celled by suppression, loculicidal, valves 

 semi-septiferous. Seeds usually solitary in each cell; testa coriaceous, shining; 

 hilum basUar, large. Embeto exalbuminous, curved ; cotyledons large, thick, fleshy, 

 often more or less confluent ; radicle short, near the hilum. 



PEINCIPAL GENEEA. 

 ^sculus. Pavia. Ungnadia. 



The little group of Sippooasfanecs, which evidently belongs to the family of Sapindacece, is only dis- 

 tinguished from the latter by its opposite digitate leaves and the 2-ovuled ovarian cells; and it must 

 further be observed that the genus Ungnadia, placed by botanists near ^scmIuh, has alternate and impari- 

 pinnate leaves, which bring it still nearer to Sapindacece. For the affinity with Aoerinecs, see this family. 



Hippocastama are chiefly North American, except Castanella [which is not referable to Hippooastaneee, 



' Included in the ' Genera Plantarum ' in Sapindaces, nadia being alternate invalidates the only character 

 where it does^ot even form a tribe ; the leaves^f Uiig- distinguishing it from Sapindacece proper. En. 



