Q2 SALICACE.K. Popiilus. 



^_ +. Stamens 60 or more: leaves deltoid, sinuateli/ crenatc ; jietloles Jiattened : 

 seeds li oy 2 lines long: youiuj bark yellowish, hecoiuiiuj light <jratj. 



3. P. Fremonti, Watson. A large tree, with gray craokeil bark and terete 

 branches: lea\es broadly deltoid or often somewhat reniibim, with a broad acute 

 apex and usually more or less of a sinus at base, few serratiires (4 to 12 on each 

 side), and petioles 1 to 2\ inches long; the petioles, branchlcts, and margins of the 

 leaves often with short spreading pubescence when young : aments with glabrous 

 rhachis and bracts ; the staminate loose, with pedicels 8 to 10 lines long and con- 

 spicuous disks 3 or 4 lines broad : styles 3 : fruiting aments 3 or 4 inches long : 

 capsules ovate, 3 or 4 lines long, on sliort stout i)edicels (a line or two long), the 

 disk 3 lines broad ; valves 3, thick-coriaceous : seeds white. — Proc. Am. Acad. x. 

 350 and 1. c. 13(5. P. moniiiftra, Newberry, Pacif. P. Pep. vi. 81); AVatson, Pot. 

 King Exped. 327. 



Var. (0 Wislizeni, Watson, 1. c. 137. I^eaves sharply acuminate, truncate or 

 slightly cuneate at base : staminate aments with shorter [)edicels and less dilateil 

 thin disks : pistillate aments very slender, 2 to G inches long : ilisk 2 or 3 lines broail : 

 capsides ovate to ovate-oblong, somewhat angled, 3- or usually 4-valved, 4 or 5 lines 

 long, on slender pedicels 2 to 8 lines long. — P. moniliftra, Torrey, Dot. ISIex. Bound. 

 204, etc. 



The typical form of the species is found on the U|)per Sacianiento River anil eastward in Nevada 

 and to S. Utah {I'alincr, I'arri/) ; the variety is the i)ievalent Cottonwood in the more soiilhcru 

 districts, ranging from Sun fiiego County (Jamul Valley, I'ahncr) and tlie Colorado Valley (Ft. 

 Yuma, Scholl) to S. Utah and the Rio Grande. 



Order XCIV. JUGLANDACE^. 



^[onoecious trees or shrubs, with alternate pinnate leaves without stipules, sterile 

 flowers in aments with usually numerous stamens and a 3 - G-lobed perianth adnato 

 to a bract, fertile flowers solitary or few and spicate, with a 2 - 5-lobed (sometimes 

 double) perianth more or less adherent to the 1-ovuled 1-celled (at length imper- 

 fectly 2 - 4-celled) ovary, and a fleshy indehiscent or 4-valved fruit containing a 

 bony nut and a large exalbuminous 2 - 4dobed orthotropous seed. Stamens with 

 very short filaments and the connective usually prolonged. Style short ; stigmas 

 2_4-lobed. Embiyo fleshy and oily, covered by a membranous testa; radicle very 

 short, superior. 



The pnncii)al genera are Jtu/hms and Cari/n, almost wholly North American, tlie latter in.'lud- 

 ing the Hickory and Pecan Nuts of tlie Alhuitic States. Three otlier small genera are Asiatic. 

 The total numher of s])eeies is 25 or 30. 



1. JUGLANS, binn. Walnut. 



Staminate aments from the previous year's wood, long, solitary or in pairs ; peri- 

 anth unequally 3-C)-lobcd; stamens 12 to 40. Fertile flowers solitary, or few in 

 a short terminal spike, the calyx adherent to the ovary, 4-toothcd and with 4 small 

 petals. Style short ; stigmas 2, linear or clavate, fringed. Pericarp fleshy, indehis- 

 cent, enclosing an irregularly rugose nut, 2-valved in germination. — Trees or large 

 •shrubs, with somewhat resinous-aromatic bark and foliage, nearly nakeil buds, and 

 unequally pinnate leaves of many serrate leaflets ; pith in plates. 



Including the Black Walnut (/. nigra), very valuable and extensively used for ealiinet pur- 



