DICOTYLEDONS. 141 



ACER. 



Characters of the family. 



1. A. RUBRUM L. Rp:d ]Maple. a small tree with red or 

 purple twigs; leaves simple, broadly ovate, jnihiiately o-5-lol>ed or 

 sometimes merely serrate or cut-tootlied, acuminate at the apex, 

 rounded or cordate at the base, smooth or pul)escent, becoming 

 briglit red in autumn; flowers appearing before tlie leaves on erect, 

 chistered ])edicels; petals red or yellow, oblong or linear; fruiting 

 pedicels elongated and drooping; samara red, smooth, wings about 

 an inch long. February-ApriL Swamps and river banks. 



2. A. Saccharum Marsh. Sugar Maple. A large tree; 

 leaves simple, palmately lobed, truncate or cordate at the base, 

 lobes sinuate-toothed and acuminate, pale and slightly pubescent 

 beneath; flowers appearing with the leaves, on clustered, droojting 

 pedicels; calyx bell-shaped, fringed; petals none; samaras smooth, 

 wings about 1-H ii^- long. April-May. In cold woods, more 

 abundant northward. The sap of this tree is the principal source 

 of maple sugar, and some forms of the tree produce the curled nuiple 

 and bird's-eye maple used in cabinet making. 



3. A. N EG UNDO L. Box Elder. A small tree; leaves opposite, 

 pinnately 3-5-foliate ; leaflets ovate, lol)ed, toothed or entire, pubes- 

 cent when young; flowers di'Pcious, ai)i)earing from lateral buds 

 before or with the leaves ; the staminate on long and drooping pedi- 

 cels, the j>istillate in drooping racemes; samaras smooth, 1-H in. 

 long. March-A})ril. River banks. Often cultivated as a (piick- 

 growing shade tree. 



74. HIPPOCASTANACEiE. lU'C'KEYI-: FAMILY. 



Trees or shrubs ; leaves opposite, long-petioled, palmately 

 (;omi)onn(l ; flowers showy, polygamous, in terminal panicles; 

 calyx 5-lobed, oblique; petals 4-5, unequal; stamens 5'S, 

 hy})ogynous : pistil 1, ovary 3-celled, 2 ovules in each cell, 

 style slender; fruit a 1-3-celled, leathery cai)sule, 1-3-seeded, 

 scL'ds with a large scar. 



iESCULUS. 



Characters of the family. 



JE. Pavia L. I{i:i» I'.i rui ^l:. Shnibs; stems erect. br:niche(L 

 4-8 ft. hi<'li ; l«-allets iisii.illv .'». l;iiie.-u|;il.' t.» luiiiow Iv nval, aeiimi- 



