DICOTYLEDONS. 45 



I. JUGLANS. 



Staminate aments cylindrical, solitary, borne on wood of 

 the previous year, stamens numerous, filaments short, calyx 

 4-6-parted ; pistillate flowers single or a few together on a 

 short peduncle at the base of the growth of the season ; calyx 

 4-parted, petals 4, minute, adnate to the ovary ; styles 2, short, 

 plumose, fruit large, globose or oval, exocarp tibrous-fleshy, 

 becoming dry, indehiscent, endocarp bony, very rough. 



1. J. NIGRA L. Black Walnut. Leaflets 13-21, ovate-lanceo- 

 late, serrate, acuminate, somewhat cordate or oblique at the base, 

 nearly smooth above, pubescent beneath, petioles minutely downy ; 

 fruit Aisually single, globose, about 2 in. in diameter. April-May. 

 On rich soil, rare near the coast. One of the most valuable of our 

 native trees, the wood being very durable and highly prized for cabi- 

 net work. 



2. J. ciNEREA L. Butternut. Leaflets 15-19, ovate-lanceo- 

 late, acuminate at the apex, rounded or slightly inefjuilateral at the 

 base, serrate, downy beneath ; petioles, branchlets, and fruit viscid- 

 pubescent ; fruit often in small clusters, oblong. April-May. More 

 connnon northward. Wood less valuable and nut less oily tlian 

 Black Walnut. The English Walnut (./. rer/id) is occasionally seen 

 in cultivation. It has 7-11 leaflets and a nearly smooth endocarp. 



II. HICORIA. 



Leaflets serrate; staminate aments usually in 3's on a 

 common peduncle, or sometimes sessile at the base of the 

 growth of the season ; calyx 2-3-parted, stamens 3-10, flla- 

 monts short ; pistillate flowers 2-5 in terminal clusters, calyx 

 1 -parted, petals none, styles 2 or 4, fimbriate ; fruit sub- 

 lobose, exocarp sei)arating nn)re or less comidetely into \ 

 vjilves, endocar}) snH)otli or anghMl. 



& 



1. II. rKCAN (Marsh) liritt. 1'i:<an. A large tree with rou-li 

 gray bark, young twigs and leaves i)ul>es('ent, nearly glabrous when 

 mature ; leaflets 11-1."), oblong-lanceolate, acuminate, serrate, falcate ; 

 slaniinate aments nearly sessile, .")-() in. long; exocarj* thin, nut oval 

 or oblong, tliin-sliellt'd. Marcli-Ajiril. Kiver-hottoms. Karely 

 native east of the Mi»is,>ii.|>i llivrr, ImiI \si<lely i)lauled lor its fruit. 



