Part 21

Distribution. Banks of streams; valley of the upper Sacramento River southward through western California to the San Pedro Mártir Mountains, Lower California; most abundant in the San Joaquin Valley, and ascending the western slopes of the southern Sierra Nevada to altitudes of 3000°.

Often planted in southern California as a shade-tree, and for the fuel produced quickly and abundantly from pollarded trees.

In San Bernardino and San Diego Counties, California, generally replaced by the var. _pubescens_ Sarg., differing in its pubescent branchlets and ranging eastward to southwestern Nevada and southern Utah. In southern Arizona and near Silver City, Grant County, New Mexico, represented by the var. _Thornberii_ Sarg., differing from the typical _P. Fremontii_ in the more numerous serratures of the leaves, in the ellipsoidal not ovoid capsules with smaller disk and shorter pedicels, and by the var. _Toumeyi_ Sarg., differing from the type in the shallow cordate base of the leaves, gradually narrowed and cuneate to the insertion of the petiole, and in the larger disk of the fruit (Fig. 124). The var. _macrodisca_ Sarg. with a broad disc nearly inclosing the ellipsoidal fruit is known only in the neighborhood of Silver City.

× _Populus Parryi_ Sarg., a probable hybrid of _P. Fremontii_ and _P. trichocarpa_, with characters intermediate between those of its supposed parents, grows naturally along Cottonwood Creek on the west side of Owens Lake, Inyo County, and in the neighborhood of Fort Tejon, Kern County, and as a street tree is not rare in San Bernardino, California.

9. Populus arizonica Sarg. Cottonwood.

_Populus mexicana_ Sarg., not Wesm.

Leaves deltoid or reniform, gradually or abruptly long-pointed at the acuminate entire apex, truncate or broad-cuneate at the wide base, finely serrate with numerous teeth, as they unfold dark red covered below with pale pubescence, pubescent above, ciliate on the margins, thin, glandular with bright red caducous glands, soon becoming glabrous, at maturity subcoriaceous, bright yellow-green, very lustrous, 1½′—2′ long and broad, with a slender yellow midrib and obscure primary veins; petioles laterally compressed, sparingly villose when they first appear, soon glabrous, 1½′—2′ long; leaves on vigorous leading shoots often rounded at apex, cuneate at base, and often 2′ long and 3′ wide, with petioles often 3′ in length. Flowers: staminate aments dense, cylindric, 1—1½′ long, the pistillate slender, many-flowered, 1½′—2′ long, becoming 3′—4′ long before the fruit ripens; disk of the staminate flower broad-oblong; stamens numerous; disk of the pistillate flower deep cup-shaped, nearly entire; ovary ovoid, rounded at apex, slightly 3 or 4-angled, short-stalked, nearly inclosed in the cup-shaped membranaceous disk. Fruit on short stout pedicels, round-ovoid, buff color, slightly 3 or 4-lobed, deeply pitted, thin-walled, about ¼′ long.

A tree, 50°—70° high, with a trunk occasionally 3° in diameter, gracefully spreading and ascending branches forming a broad open head of wide-spreading branches, and slender often pendulous branchlets, pale green and glabrous or puberulous when they first appear, soon becoming glabrous, and light yellow during their first season. Winter-buds narrow, acute, light orange-brown, puberulous toward the base of the outer scales, the terminal about ¼′ long, and two or three times as large as the much-compressed oblong lateral buds. Bark pale gray or rarely white, and deeply divided into broad flat ridges.

Distribution. Banks of mountain streams; southwestern California (Mill Creek, above Forest Home, San Bernardino Mountains) and southern and central Arizona; widely distributed through northern Mexico (_var. Jonesii_ Sarg.); well distinguished from the other Cottonwoods of the United States by its small fruit.

Often planted as a street tree in the towns of southern Arizona.

10. Populus texana Sarg.

Leaves thin, glabrous, broadly ovate, gradually narrowed, long-pointed and acuminate at apex, truncate at base, coarsely crenately serrate below the middle, entire above, 3′—3¼′ long and 2¼′—2½′ wide; petioles slender, compressed, 1½′—2½′ in length. Flowers not seen. Fruit: aments slender, glabrous, 2½′—3′ long; fruit oblong-ovoid, acute, deeply pitted, glabrous, thin-walled, 3-valved, ⅓′ in length; disk slightly lobed; pedicel slender, 1/16′—⅛′ in length; seeds ovoid, acuminate, 1/16′ long.

A tree up to 60° high, with a trunk sometimes 3° in diameter, stout more or less pendulous branches and stout glabrous pale yellow-brown branchlets. Winter-buds acuminate, glabrous.

In cañons and along the streams of northwestern Texas, where it appears to be the only Cottonwood.

11. Populus McDougallii Rose.

Leaves broadly ovate, abruptly short-pointed or acute at apex, broadly or acutely cuneate or truncate, or on vigorous shoots rarely slightly cordate at base, finely or often coarsely crenately serrate, bluish green, thin, pubescent on the under sides of the midrib and primary veins early in the season, otherwise glabrous, 1½′—3′ long and broad, with slender midribs and veins; petioles slender, slightly compressed, pubescent early in the season, becoming glabrous, 1½′—2′ in length. Flowers not seen. Fruit: aments glabrous, short-stalked, 2′—2½′ long; fruit ovoid and acute at apex to ellipsoidal and acute or acuminate at ends, glabrous, slightly pitted, thin-walled, 3-valved, 5/12′—½′ long; disk not more than ⅛′ in diameter; pedicels glabrous, ⅛′—⅕′ in length; seeds oblong-ovoid, acuminate, ⅛′ long.

A tree rarely 90°—110° high, usually much smaller, with erect branches and slender branchlets pubescent or puberulous when they first appear, sometimes becoming glabrous during their first season, and sometimes pubescent during two years.

Distribution. Banks of streams and springs, San Bernardino County, California (Cottonwood Springs, Meca, etc.), and eastward to the bottoms of the Colorado River from Clark County, Nevada, to Yuma, Arizona, and probably the only Cottonwood in this arid region.

Often planted as a street tree in the towns of southwestern California and of adjacent Nevada and Arizona.

12. Populus Wislizenii Sarg. Cottonwood.

Leaves broadly deltoid, abruptly short- or long-pointed at apex, truncate or sometimes cordate at the broad entire base, coarsely and irregularly crenately serrate except toward the entire apex, coriaceous, glabrous, yellow-green and lustrous, 2′—2½′ long, usually about 3′ wide, with a slender yellow midrib, thin remote primary veins and conspicuous reticulate veinlets; petioles slender, glabrous, 1½′—2′ long; on vigorous shoots often 3½′—4′ long and wide with petioles 3½′—4′ in length. Flowers: aments 2′—4′ long, the pistillate becoming 4′—5′ long before the fruit ripens; scales scarious, light red, divided at the apex into elongated filiform lobes; disk of the staminate flower broad and oblique; stamens numerous, with large oblong anthers and short filaments; disk of the pistillate flower cup-shaped, irregularly dentate, inclosing to the middle the long stalked ovary full and rounded at apex, with 3 broad crenulate lobed stigmas raised on the short branches of the style. Fruit oblong-ovoid, thick-walled, acute, 3 or 4-valved, slightly ridged, buff color, ¼′ long; pedicels slender, ½′—¾′ in length and placed rather remotely on the slender glabrous rachis of the ament.

A large tree, with wide-spreading branches, and stout light orange-colored glabrous branchlets. Winter-buds acute lustrous, puberulous. Bark pale gray-brown, deeply divided into broad flat ridges. Wood used as fuel, for fence-posts and the rafters of Mexican houses.

Distribution. Western Texas through New Mexico to the valley of Grand River, western Colorado (Grand Junction, Mesa County); common in the valley of the Rio Grande in western Texas and New Mexico, and the adjacent parts of Mexico.

Often planted as a shade tree in New Mexico.

13. Populus Sargentii Dode.

_Populus deltoides_ var. _occidentalis_ Rydb.

Leaves ovate, usually longer than broad, abruptly narrowed into a long slender entire acuminate point or rarely rounded at apex, truncate or slightly cordate at base, and coarsely crenately serrate, as they unfold slightly villose above and tomentose on the margins, soon glabrous, light green and very lustrous, 3′—3½′ long, 3½′—4′ wide, with a thin midrib, slender primary veins and reticulate veinlets occasionally furnished on the upper side at the insertion of the petiole with one or two small glands; petioles slender, compressed laterally, 2½′—3½′ long. Flowers: aments short-stalked, glabrous, the staminate 2′—2½′ in length, the pistillate becoming 4′—8′ long before the fruit ripens; scales fimbriately divided at apex, scarious, light brown; disk of the staminate flower broad, oblique, slightly thickened on the margins; stamens 20 or more, with short filaments and yellow anthers; disk of the pistillate flower cup-shaped, slightly lobed on the margin; ovary subglobose, with 3 or 4 sessile dilated or laciniately lobed stigmas. Fruit oblong-ovoid, gradually or abruptly narrowed to the blunt apex, thin-walled, about ⅖′ long and three or four times longer than the pedicel; seeds oblong-obovoid, rounded at apex, about 1/16′ in length.

A tree 60°—90° tall with a trunk often 6° or 7° in diameter, erect and spreading branches forming a broad open head, and stout glabrous light yellow often angular branchlets conspicuously roughened by the elevated scars of fallen leaf-stalks. Winter-buds ovoid, acute, with light orange-brown puberulous scales. Bark pale, thick, divided by deep fissures into broad rounded ridges broken into closely appressed scales.

Distribution. The common Cottonwood along the streams in the eastern foothill region of the Rocky Mountains from Saskatchewan to New Mexico, and ranging east to the Dakotas, western Nebraska, Kansas, Oklahoma and Texas.

Often planted as a shade and street tree in the Rocky Mountain states; hardy in Massachusetts.

14. Populus balsamifera L. Cottonwood.

_Populus angulata_ Michx. f.

Leaves ovate, longer than broad, abruptly acuminate and often long-pointed at apex, subcordate or rarely truncate at the wide base, finely crenately serrate with glandular teeth, furnished on the upper surface at the insertion of the petiole with two glands, thick, glabrous, green and lustrous on the upper surface, paler below, 5′—7′ long and 4′—5′ wide, with stout midribs and conspicuous primary veins sometimes sparingly pilose below early in the season; petioles much compressed laterally, often more or less tinged with red, 3′—4′ in length. Flowers: aments glabrous, short-stalked, the staminate densely flowered, 1½′—2′ long, ½′—¾′ in diameter, the pistillate slender, sparsely flowered, 3′—3½′ in length; scales scarious, light brown, glabrous, dilated and irregularly divided at apex into filiform lobes; disk of the staminate flower broad, oblique, slightly thickened and revolute on the margins; stamens 60 or more, with short filaments and large dark red anthers; disk of the pistillate flower broad, slightly crenate, inclosing about ⅓′ of the ovoid obtusely pointed ovary, with 3 or 4 sessile dilated laciniately lobed stigmas. Fruit on aments 8′—12′ in length, ellipsoidal, pointed, thin-walled, 3 or 4-valved, ⅓′ long, the disk little enlarged; pedicels ⅙′—¼′ in length; seeds oblong-obovoid, rounded at apex, light brown, about 1/12′ long.

A large tree with massive spreading branches and stout yellow-brown often angular branchlets. Winter-buds resinous, acute, ½′ long with light chestnut brown lustrous scales.

Distribution. Shores of Lake Champlain (Shelburne Point, Chittenden County), Vermont; western New York; Island of the Delaware River above Easton, Northampton County, Pennsylvania; Baltimore County, and Bare Hills, Maryland; northern banks of the Potomac River opposite Plummer’s Island near Washington, D.C.; Artisia, Lowndes County, and Starkville, Oktibbeha County, Mississippi; rare and local.

Populus balsamifera var. virginiana Sarg. Cottonwood.

_Populus deltoidea_ Marsh. at least in part. _Populus nigra β virginiana_ Castiglioni.

Leaves deltoid to ovate-deltoid, acuminate with entire points, truncate, slightly cordate or occasionally abruptly cuneate at the entire base, crenately serrate above, with incurved glandular teeth, fragrant with a balsamic odor, glabrous, thick and firm, light bright green and lustrous, paler on the lower than on the upper surface, 3′—5′ long and broad, with a stout yellow midrib often tinged with red toward the base, raised and rounded on the upper side, and conspicuous primary veins; petioles slender, pilose at first, soon glabrous, compressed laterally, yellow often more or less tinged with red, 2½′—3½′ long. Flowers and Fruit: as on the type.

A tree, sometimes 100° high, with a trunk occasionally 7°—8° in diameter, divided often 20°—30° above the ground into several massive limbs spreading gradually and becoming pendulous toward the ends, and forming a graceful rather open head frequently 100° across, or on young trees nearly erect above and spreading below almost at right angles with the stem, and forming a symmetrical pyramidal head, and stout branchlets marked with long pale lenticels, terete, or, especially on vigorous trees, becoming angled in their second year, with thin more or less prominent wings extending downward from the two sides and from the base of the large 3-lobed leaf-scars. Winter-buds very resinous, ovoid, acute, the lateral much flattened, ½′ long, with 6 or 7 light chestnut-brown lustrous scales. Bark thin, smooth, light yellow tinged with green on young stems and branches, becoming on old trunks 1½′—2′ thick, ashy gray, and deeply divided into broad rounded ridges broken into closely appressed scales. Wood dark brown, with thick nearly white sapwood, warping badly in drying and difficult to season.

Distribution. Banks of streams, often forming extensive open groves, and toward the western limits of its range occasionally in upland ravines and on bluffs; Province of Quebec and the shores of Lake Champlain, through western New England, western New York, Pennsylvania west of the Allegheny Mountains, and westward to southern Minnesota, North and South Dakota, eastern Nebraska, eastern Kansas, Oklahoma and Texas, and southward through the Atlantic states from Delaware to western Florida, and through the Gulf states to western Texas (Brown County). In the south Atlantic states and the valley of the Lower Ohio River and southward sometimes replaced by a variety with leaves covered above when they unfold with soft white hairs and below with close pubescence more or less persistent during the season especially on the midribs and veins (var. _pilosa_ Sarg.).

Often planted for shelter and ornament on the treeless plains and prairies between the Mississippi River and the Rocky Mountains, and as an ornamental tree in the eastern United States and largely in western and northern Europe.

× _Populus canadensis_ Moench, believed to be a hybrid between the northern glabrous form of _P. balsamifera_ and the European _P. nigra_ L., with several varieties, is cultivated in Europe and occasionally in the United States. The best known of these varieties, × _P. canadensis_ var. _Eugenie_ Schelle, the Carolina Poplar of American nurseries, believed to be a hybrid of the northern Cottonwood with the Lombardy Poplar, has been planted in the United States in immense numbers.

× _Populus Jackii_ Sarg., believed to be a hybrid of the northern Cottonwood with _P. tacamahacca_, with characters intermediate between those of its supposed parents, grows spontaneously near the mouth of the Chateaugay River and at Beauharnois, Province of Quebec, and at South Haven, Michigan, and is now occasionally cultivated.

15. Populus Palmeri Sarg.

Leaves thin, ovate, gradually or abruptly contracted at apex into a narrow acuminate entire point, cuneate or rounded at the broad base, finely serrate with incurved teeth, ciliate on the margins when they unfold, otherwise glabrous, 2½′—5′ long and 1½′—2¼′ wide; petioles slender, glabrous, 1½′—2½′ in length. Flowers not seen. Fruit: aments glabrous, 12—15 cm. long; fruit ovoid, obtuse, slightly pitted, puberulous, thin-walled, 4-valved, ¼′—⅓′ long, the disk deeply lobed; pedicel slender, ¼′—⅓′ in length.

A tree 60° tall, with a straight trunk 3° in diameter, erect smooth pale branches forming an open pyramidal head, the lower branches smaller, horizontal or pendulous, and slender glabrous branchlets light reddish brown early in the season, becoming pale grayish brown in their second year. Bark pale, 3′—4′ thick, deeply divided by wide fissures into narrow ridges.

Distribution. In moist fertile soil near springs, at the base of high chalky bluffs of Nueces Cañon of the upper Nueces River, Uvalde County, growing with _Salix nigra_ var. _Lindheimeri_, _Carya pecan_, _Morus rubra_ and _Ulmus crassifolia_, and at Strawn, Palo Pinto County, Texas.

2. SALIX L. Willow.

Trees or shrubs, with watery juice, scaly bark, soft wood, slender terete tough branchlets often easily separated at the joints, and winter-buds covered by a single scale of 2 coats, the inner membranaceous, stipular, rarely separable from the outer, inclosing at its base 2 minute opposite lateral buds alternate with 2 small scale-like caducous leaves coated with long pale or rufous hairs. Leaves variously folded in the bud, alternate, simple, lanceolate, obovate, rotund or linear, penniveined; petioles sometimes glandular at the apex, and more or less covering the bud, in falling leaving U-shaped or arcuate elevated leaf-scars displaying the ends of 3 small equidistant fibro-vascular bundles; stipules oblique, serrate, small and deciduous, or foliaceous and often persistent, generally large and conspicuous on vigorous young branches, leaving in falling minute persistent scars. Flowers in sessile or stalked aments, terminal and axillary on leafy branchlets; scales of the ament lanceolate, concave, rotund or obovate, entire or glandular-dentate, of uniform color or dark-colored toward the apex, more or less hairy, deciduous or persistent; disk of the flower nectariferous, composed of an anterior and posterior or of a single posterior gland-like body; stamens 3—12 or 1 or 2, inserted on the base of the scale, with slender filaments free or rarely united and usually light yellow, glabrous, or hairy toward the base, and small ovoid or oblong anthers generally rose-colored before anthesis, becoming orange or purple; ovary sessile or stipitate, conic, obtuse to subulate-rostrate, glandular at the base, glabrous, tomentose or villose, with an abbreviated style divided into 2 short recurved retuse or 2-parted stigmas; ovules 4—8 on each of the 2 placentas. Fruit an acuminate 1-celled capsule separating at maturity into 2 recurved valves. Seeds minute, narrowed at the ends, dark chestnut-brown or nearly black; cotyledons oblong.

Salix inhabits the banks of streams and low moist ground, the alpine summits of mountains, and the Arctic and sub-Arctic regions of the northern hemisphere, ranging south in the New World, with a few species, through the West Indies and Central America to Brazil, and the Andes of Chile, and in the Old World to Madagascar, southern Africa, the Himalayas, Burmah, the Malay peninsula, Java, and Sumatra. Of the 160 or 170 species which are now recognized about seventy are found in North America. Of these twenty-four attain the size and habit of trees, the others being small and sometimes prostrate shrubs. Of exotic species, _Salix alba_ L., and _Salix fragilis_ L., important European timber-trees, are now generally naturalized in the northeastern states. The flexible tough branches of several species are used in making baskets; the bark is rich in tannic acid and is used in tanning leather and yields salicin, a bitter principle valuable as a tonic. Many of the species are cultivated as ornamental trees.

_Salix_ is the classical name of the Willow-tree.

CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES