Jtolans. JUGLANDACE^. 179 



Group 7. Flowers moncecious or dioecious ; the sterile, and sometimes the fertile also, 

 in aments, or in heads or spikes, either furnished with a calyx or achlamydeous. 

 Ovary several-celled, but the fruit always (except in Liquidambar) one-celled. 

 — Trees or shrubs, or (in Urticace^) herbs. 



Order XCVIII. JUGLANDACEiE. DC. The Walnut Tribe. 



Flowers monoecious, incomplete. Sterile fl. in aments. Calyx adnate to the 

 bracts or scales of the ament, oblique, unequally 2 - 6-parted. Stamens 

 indefinite. Fertile fl. few, clustered or sometimes racemose. Calyx ad- 

 herent to the ovary ; the limb minute, 3 - 5-parted. Petals none, or rarely 

 3-5 and minute. Ovary 2 - 4-celled below, 1-celled above, with a single 

 ovule : styles 1-2, very short : stigmas 2-4, unequal, elongated, sometimes 

 discoid and lobed. Fruit drupaceous ; the fepicarp fibrous-fleshy or coriaceous, 

 not opening, or separating into 4 valves : endocarp (nut-shell) bony, smooth or 

 rugose- furrowed, 2 - 4-celled below, 1-celled above. Seed without albumen, 

 4-lobed ; the cotyledons fleshy and oily, sinuous : radicle very short — Trees, 

 with alternate pinnated leaves, destitute of stipules. 



1. JUGLANS. Linn. (excl. spec); Nutt. gen. 2. p. 220; Endl. gen. 5890. WALNUT. 



[ So named from the Latin, Jovii glans, or the nut of Jupiter ; on account of its excellence.] 



Sterile fl. Aments simple, cylindrical, imbricated. Bracts entire. Calyx 5 - 6-parted. 

 Stamens 8 - 40. Fertile fl. solitary or several together on a peduncle at the extremity 

 of the branches. Bracts none or minute. Calyx 4-cleft or 4-toothed. Corolla 4-petalled, 

 inserted at the summit of the calyx, between its teeth. Styles 2, very short : stigmas 2, 

 somewhat clavate. Drupe fibrous-fleshy, indehiscent ; the nut-shell rugose and irregularly 

 furrowed. — Trees, with unequally pinnate leaves. Sterile and fertile flowers proceeding 

 from separate buds. Pith separating into numerous thin disks. 



1. JuGLANS NIGRA, Linn. Black Walnut. 



Leaflets ovate -lanceolate, somewhat cordate at the base, the under surface and petioles 

 slightly pubescent ; drupe globose, roughly dotted, spongy ; nut nearly globose, corrugated. 

 —Linn. sp. 2. p. 997 ; Michx. fl. 2. p. 191 ; Michx.f. sylv. 1. f. 30 ; Pursh, fl. 2. p. 636 ; 

 Nutt. gen. 2. p. 220 ; Ell. sk. 2. p. 622 ; Torr. compend. p. 357 ; Beck, hot. p. 335 ; Dar. 

 lingt. fl. Cest. p. 543 ; Loud. enc. trees <^ shr. p. 734. 



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