24 HOUGH'S AMERICAN WOODS. 



brown color, and the sap-wood yellowish or greenish white. Specific 

 Gravity, 0.7263 ; Percentage of Ash, 0.60; Relative Approximate Fuel 

 Value, 0.7219 ; Coefficient of Elasticity, 109628 ; Modulus of Rupture, 

 1066 ; Resistance to Longitudinal Pressure, 592 ; Resistance to Indenta- 

 tion, 205 ; Weight of a Cubic Foot in Pounds, 45.26. 



USES. A very valuable timber for agricultural implements, wheel- 

 stock, axe-helves, etc. It is particularly valuable for the hubs of wheels 

 owing to the difficulty with which it splits, and its superiority over Hick- 

 ory for axe-helves is attested by the greater price which they command 

 in market. 



MEDICINAL PROPERTIES. None are claimed of this species. 



ORDER JUGLANDACE2E: WALNUT FAMILY. 



Leaves alternate, pinnate and without stipules. Floicers monoecious and apetalous, 

 except in some cases in the fertile flowers. Sterile flowers in catkins with an irregu- 

 lar calyx adnate to the scale of the catkin. Fertile flowers solitary or in small clus- 

 ters, with calyx regularly 3-5-lobed, adherent to the incompletely 2-4- celled, but 

 1-ovuled ovary. Fruit a sort of dry drupe (a tryma), with a fibrous and more or less 

 fleshy and coriaceous outer coat (shuck) very astringent to the taste, a hard, bony in- 

 ner coat (shell), and a 2-4-Jobed seed, which is orthotropous, with thick, oily and 

 often corrugated cotyledons and no albumen. 



All representatives of the order are trees. 



GENUS JUGLANS, L. 



Leaves odd-pinnate, with numerous serrate leaflets; leaf -buds few-scaled or nearly 

 naked. Sterile flowers in long, simple, imbricated, axillary catkins from the wood of 

 the preceding year; calyx unequally 3-6-cleft; stamens 12-40 with very short and free 

 filaments. Fertile flowers several in a cluster or solitary at the ends of the branches; 

 calyx 4-toothed and bearing in its sinuses 4 small petals; styles 2, very short; stigmas 

 2, somewhat club-shaped and fringed. Fruit drupaceous with a fibrous and spongy, 

 somewhat fleshy, indehiscent epicarp (shuck), and a rough irregularly furrowed en- 

 docarp (shell); embryo edible and wholesome. 



Trees with strong-scented resinous-aromatic bark and a pith which separates into 

 thin transverse disks. (Juglans is contracted from Latin Jovis glans, the nut of Jove.} 



35. JUGLANS NIGRA, L. 

 BLACK WALNUT. 



Ger., Schwarze Wallnussbaum ; Fr., Noyer noir ; Sp., Nogal negro. 



SPECIFIC CHARACTERS. Leaflets ovate-lanceolate, somewhat heart-shaped at the 

 base, taper-pointed, smooth above, lower surface and petioles minutely glandular 

 pubescent, emitting, when bruised, a characteristic aromatic odor. Flowers (April 

 and May) as described for the genus. Fruit (October) globose, 2 inches in diameter 

 with roughly dotted surface, odoriferous, spongy; nut globose, somewhat flattened, 

 corrugated. 



A tall and handsome forest tree with dark, deeply furrowed bark and 

 sometimes attaining the height of 125 ft. (38m.) and 8 ft. (2.5 m.) in di- 

 ameter of trunk. When growing in the open it develops a full, round top 

 of symmetrical outline and casting a dense shade. 



