S50 HIPPOCASTANACE^. JEscvlvs, 



Leares compound, pinnatcly 3-5-foliolate : leaflets petiolulatc. — Otherwise 

 same as Acer. 



1. N. aceroides (Mosnch): leaflets 3-5, ovate or oval, acuminate, sparing- 

 ly and unequally tootlied above the middle, the upper ones sometimes con- 

 fluent ; fertile racemes elongated, pendulous ; fruit oblong, with large up- 

 wardly dilated arcuate wings. — Manch, meth. p. 334. N. fraxinifolium, 

 Nutt. f gen. 1. p. 253 ; nC. prodr. 1. p. 596; Hook. Jl. Bor.-Am. 1. p. 114. 

 Acer Negundo, Linn.; Michv. ! fl. 2. p. 253; ^ Mich.x. f. sylv. 1. t. 46. 



In low grounds,' Canada (lat. 54° ex Hook.) to N. Carolina ! & Arkansas!: 

 April. — Trunk 15-30 feet high, with a smooth yellowish-green bark. The 

 sap contains sugar in small quantity. Leaves slightly pubescent, varying^ 

 from ovate to nearly lanceolate. FloAvers yellowish-green. Stamens most- 

 ly 5. Wings of the fruit broad and incurved at the apes. — Ash-leaved Ma- 

 ple. Box-Elder. 



2. N. Calif or nicum. : young leaves villous, 3-foliolate; leaflets 3-lobed f 

 lobes incised or toothed. — N. Mexicanum, DC. I. c? 



California, Douglas ! — Our specimens have neither fruit nor fall-growQ 

 leaves ; but they appear to belong to a very distinct species. The leaflets are 

 all lobed and incised ; the terminal one largest and broadly cuneiform at the 

 base. Flowers very much crowded : sepals unequal. — The N. Mexicanum is 

 so briefly characterised that it is impossible to determine the question of its; 

 identity with cur species. 



Order XLIV. HIPPOCASTANACE^. DC. 



Sepals 5, usually united into a campanulate or tubular 5-toothed ca- 

 lyx: aestivation imbricated. Petals 5, or 4 by the suppression of the 

 inferior one, commonly unequal and irregular, unguiculate, hypogy- 

 nous. Stamens 6-8, commonly 7, distinct, unequal, inserted upon the 

 hypogynous disk : anthers oval, versatile. Ovary roundish, composed 

 of 3 united carpels, 3-celled, with 2 collateral ovules in each cell % 

 style filiform, acute. Fruit subglobose, coriaceous, 3- (or frequently 

 by suppression 1-2-) celled, 2-3.valved, with loculicidal dehiscence. 

 Seeds solitary or very few, large, with a smooth or shining testa, and 

 a broad pale hilum, somewhat campulitropous, with no albumen. Co- 

 tyledons very thick and fleshy, gibbous, cohering, remaining under 

 ground in germination : radicle conical, curved : plumule large, 2-leav. 

 ed. — Trees or shrubs. Leaves opposite (in Ungnodia alternate), ex- 

 stipulate, compound : leaflets serrate. Flowers showy : pedicels arti- 

 culated, 



1. ^SCULUS. Linn.; Juss. gen. p. 251. 



Hippocastanum, Touni. ,- Garin. — ^sculus & Pavia, ^oc;A. ; DC. — ^scalus, 

 Pavia, Macrothyrsus, <f Calothyrsus, Spack. 



Sepals united into a 5-toothed campanulate or tubular calyx. Petals 4-5, 

 more or less unequal. Otherwise as in the character of the Order. — Leaves 



