Part 80

The generic name is in honor of Johann Gottlieb Gleditsch (1714—1786), professor of botany at Berlin.

CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES.

Legume linear-oblong, elongated, many-seeded, indehiscent. Legume 12′—18′ long, with pulp between the seeds; ovary hoary-tomentose. 1. G. triacanthos (A, C). Legume 4′—5′ long, without pulp between the seeds. 2. G. texana (C). Legume oval, oblique, 1—3-seeded, without pulp, tardily dehiscent; ovary glabrous. 3. G. aquatica (A, C).

1. Gleditsia triacanthos L. Honey Locust.

Leaves 7′—8′ long, 18—28-foliolulate or sometimes bipinnate, with 4—7 pairs of pinnæ, those of the upper pair 4′—5′ long, when they unfold hoary-tomentose, and at maturity pubescent on the petiole and rachis, the short stout petiolules, and the under surface of the midrib of the oblong-lanceolate leaflets, unequal at base, acute or slightly rounded at apex, remotely crenulate-serrate, dark green and lustrous above, dull yellow-green below, 1′—1½′ long and ½′ wide; turning in the autumn pale clear yellow. Flowers appearing in June when the leaves are nearly fully grown from the axils of leaves of previous years; the staminate in short many-flowered pubescent racemes 2′—2½′ long and often clustered; the pistillate in slender graceful few-flowered usually solitary racemes 2½′—3½′ long; calyx campanulate, narrowed at base, the acute lobes thickened, revolute and ciliate on the margins, villose with pale hairs, rather shorter than and half as wide as the erect acute petals; filaments pilose toward the base; anthers green; pistil rarely of 2 carpels, hoary-tomentose. Fruit 12′—18′ long, dark brown, pilose and slightly falcate, with straight thickened margins, 2 or 3 together in short racemes on stalks 1′—1½′ long, their walls thin and tough, contracting in drying by a number of corkscrew twists, and falling late in the autumn or early in winter; seeds oval, ⅓′ long, separated by thick succulent pulp.

A tree, 75°—140° high, with a trunk 2°—3° or occasionally 5°—6° in diameter, slender spreading somewhat pendulous branches forming a broad open rather flat-topped head, and branchlets marked by minute lenticels, at first light reddish brown and slightly puberulous, soon becoming lustrous and red tinged with green, and in their second year greenish brown and armed with stout rigid long-pointed simple or 3-forked spines at first red, and bright chestnut-brown when fully grown, or rarely unarmed (var. _inermis_ Pursh.). Bark of the trunk ½′—¾′ thick, divided by deep fissures into long narrow longitudinal ridges and roughened on the surface by small persistent scales. Wood hard, strong, coarse-grained, very durable in contact with the ground, red or bright red-brown, with thin pale sapwood of 10—12 layers of annual growth; largely used for fence-posts and rails, for the hubs of wheels, and in construction.

Distribution. Borders of streams and intervale lands, in moist fertile soil, usually growing singly or occasionally covering almost exclusively considerable areas; less commonly on dry sterile gravelly hills; western slope of the Alleghany Mountains of Pennsylvania, westward through southern Ontario and southern Michigan to southeastern Minnesota, southern Iowa, southeastern South Dakota, eastern Nebraska, eastern Kansas, and Oklahoma to the Salt Fork of the Arkansas River (near Alva, Woods County) and to creek valleys near Cache, Comanche County (_G. W. Stevens_), and southward to northern Alabama, Mississippi and western Florida and to the valley of the Brazos River, eastern Texas; and in the cañon of Paloduro Creek near Canyon, Randall County, northwestern Texas (_E. J. Palmer_); in Pennsylvania and West Virginia occasionally on the eastern slopes of the Appalachian Mountains; attaining its largest size in the valleys of small streams in southern Indiana and Illinois; now often naturalized in the region east of the Alleghany Mountains. The var. _inermis_, the prevailing form in Taney County, southern Missouri.

Often cultivated as an ornamental and shade tree in all countries of temperate climates.

2. Gleditsia texana Sarg. Locust.

Leaves 6′—7′ long, 12—22-foliolulate, with a slender rachis at first puberulous, ultimately glabrous, or often bipinnate, usually with 6 or 7 pairs of pinnæ, the lower pairs frequently reduced to single large leaflets; leaflets oblong-ovate, often somewhat falcate, rounded or acute or apiculate at apex, obliquely rounded at base, finely crenately serrate, thick and firm in texture, dark green and lustrous above, pale below, ½′—1′ long, with a short petiolule coated while young, like the base of the slender orange-colored midrib, with soft pale hairs. Flowers appearing toward the end of April, the staminate dark orange-yellow, in slender glabrous often clustered racemes lengthening after the flowers begin to open and finally 3′—4′ in length; calyx campanulate, with acute lobes thickened on the margins, villose-pubescent and rather shorter and narrower than the puberulous petals; stamens with slender filaments villose near the base and green anthers; pistillate flowers unknown. Fruit 4′—5′ long, 1′ wide, straight, much compressed, rounded and short-pointed at apex, full and rounded at the broad base, thin-walled, dark chestnut-brown, puberulous, slightly thickened on the margins, many-seeded, without pulp; seeds oval, compressed, dark chestnut-brown, very lustrous, ½′ long.

A tree, 100°—120° high, with a trunk rarely exceeding 2½° in diameter, ascending and spreading branches forming a narrow head, and comparatively slender more or less zigzag branchlets roughened by numerous small round lenticels, light orange-brown when they first appear, gray or orange-brown during their first year, ashy gray the following season, and unarmed. Bark thin and smooth.

Distribution. Only in a single grove on the bottom-lands of the Brazos River, near the town of Brazoria, Brazoria County, Texas.

3. Gleditsia aquatica Marsh. Water Locust.

Leaves 5′—8′ long, 12—20-foliolate, or bipinnate, with 3 or 4 pairs of pinnæ; leaflets ovate-oblong, usually rounded or rarely emarginate at apex, unequally cuneate at base, slightly and remotely crenate or often entire below the middle, glabrous with the exception of a few hairs on the short stout petiolule, dull yellow-green and lustrous on the upper surface, dark green on the lower surface, about 1′ long and ⅓′—½′ wide. Flowers appearing in May and June after the leaves are fully grown on short stout purple puberulous pedicels, in slender racemes 3′—4′ long; calyx-tube covered with orange-brown pubescence, the lobes narrow, acute, slightly pilose on the two surfaces, as long as but narrower than the green erect petals rounded at apex; filaments hairy toward the base; anthers large, green; ovary long-stipitate, glabrous. Fruit fully grown in August, pendent in graceful racemes, obliquely ovoid, long-stalked, crowned with a short stout tip, thin, 1′—2′ long, 1′ broad, without pulp, its valves thin, tough, papery, bright chestnut-brown, lustrous and somewhat thickened on the margins; seeds 1 or rarely 2 or 3, flat, nearly orbicular, orange-brown, ½′ in diameter.

A tree, 50°—60° high, with a short trunk 2°—2½° in diameter, usually dividing a few feet from the ground into stout spreading often contorted branches forming a wide irregular flat-topped head, and glabrous orange-brown branchlets becoming in their second year gray or reddish brown, marked by occasional large pale lenticels, and armed with usually flattened simple or short-branched straight or falcate sharp rigid spines 3′—5′ long, about ½′ broad at the base, and dark red-brown and lustrous. Bark ⅛′—¼′ thick, smooth, dull gray or reddish brown, and divided by shallow fissures into small plate-like scales. Wood heavy, very hard and strong, coarse-grained, rich bright brown tinged with red, with thick light clear yellow sapwood of about 40 layers of annual growth.

Distribution. Eastern South Carolina to Florida, through the coast region of the Gulf states to the valley of the Brazos River, Texas, and northward through western Louisiana and southern Arkansas to northwestern Mississippi, middle Kentucky and Tennessee, the bottoms of the Mississippi at La Pointe, Saint Charles County, Missouri, western and southern Illinois and southwestern Indiana; rare east of the Mississippi River and only in deep river swamps; very abundant and of its largest size westward on rich bottom-lands; in Louisiana and Arkansas often occupying extensive tracts submerged during a considerable part of the year.

9. PARKINSONIA L.

Trees or shrubs, with smooth thin bark and terete branches often armed with simple or 3-forked spines. Leaves abruptly bipinnate, alternate or fascicled from earlier axils, short-petiolate, the rachis short and spinescent, with 2—4 secondary elongated rachises bearing numerous minute opposite entire leaflets without stipels; stipules short, persistent and spinescent, or caducous. Flowers perfect on thin elongated jointed pedicels from the axils of minute caducous bracts, in slender axillary solitary or fascicled racemes; calyx short-campanulate, 5-lobed, the lobes slightly imbricated or subvalvate in the bud, narrow, membranaceous, nearly equal, becoming reflexed, deciduous; petals bright yellow, unguiculate, much longer than the lobes of the calyx, spreading, the upper petal rather broader than the others and glandular at the base of the claw; stamens 10, inserted in 2 rows on the margin of the thin disk, free, slightly declinate, those of the outer row opposite the sepals and rather longer than the others; filaments villose below the middle, the upper filament enlarged at base and gibbous on the upper side; anthers uniform, versatile; ovary short-stipitate, pilose, contracted into a slender filiform incurved style infolded in the bud and tipped with a minute stigma; ovules numerous, suspended from the inner angle of the ovary. Legume linear, torulose, acuminate at the ends, 2-valved, the valves thin, convex by the growth of the seeds, contracted between and beyond them, longitudinally striate. Seeds oblong, suspended longitudinally on a slender funicle; hilum minute, near the apex; seed-coat thin, crustaceous, light brown; embryo inclosed on the sides only by thick layers of horny albumen; cotyledons oval, flat, slightly fleshy, the radicle very short and straight.

Parkinsonia, with four species, is confined to the warm parts of America and to southern Africa. Two species occur within the limits of the United States.

The genus is named for John Parkinson (1567—1650), an English botanical author, and herbalist to James I.

CONSPECTUS OF THE NORTH AMERICAN SPECIES.

Flowers in long slender racemes; petals imbricated in the bud; stamens shorter than the petals; legume 1—8-seeded, 12′—18′ long; leaves 7′—8′ long; rachis of the pinnæ flat, wing-margined, 50—60-foliolate; branches with spines. 1. P. aculeata (G, H). Flowers in short racemes; petals valvate in the bud; stamens longer than the petals; legume 1—2-seeded; leaves about 1′ long; rachis of the pinnæ terete, 8—12-foliolate; branches without spines. 2. P. microphylla (G, H).

1. Parkinsonia aculeata L. Retama. Horse Bean.

Leaves of two forms, short-petiolate, persistent, light green and glabrous, except for a few hairs on the lower part of the young secondary rachis, 12′—18′ long; primary leaves on young branches, with 2—4 pinnæ, and a spinescent rachis developing into a stout ridged persistent short-pointed chestnut-brown spine 1′—1½′ long and marked near the base by the prominent scars left by the fall of the pinnæ; stipules persistent, appearing as lateral spiny branches on the spines; secondary leaves fascicled from the axils of the primary leaves, nearly sessile with a short terete spinescent rachis and 2 pinnæ; pinnæ flat, 12′—18′ in length, wing-margined, acute at apex, with 25—30 pairs of ovate or obovate petiolulate leaflets, 1/16′—⅛′ long. Flowers appearing on the growing branches during the spring and summer, and in the tropics throughout the year, on slender pedicels ⅓′—½′ in length, in slender erect racemes 5′—6′ long; petals bright yellow, the upper one marked near the base on the inner surface with conspicuous red spots; stamens shorter than the petals. Fruit hanging on pedicels ½′—¾′ in length, in graceful racemes, 2′—4′ long, long-pointed, dark orange-brown, slightly pilose, compressed between the remote seeds; seeds ⅓′ long, nearly terete, with thick albumen and a bright yellow embryo.

A tree, 18°—30° high, with a trunk sometimes a foot in diameter, usually separating 6°—8° from the ground into slender spreading somewhat pendulous branches forming a wide graceful head, and slightly zigzag branchlets puberulous and yellow-green during their first season, becoming glabrous, gray or light orange color and roughened by lenticels in their second and third years. Bark of the trunk about ⅛′ thick, brown tinged with red, the generally smooth surface broken into small persistent plate-like scales. Wood heavy, hard, close-grained, with very thick lighter colored sapwood tinged with yellow.

Distribution. Low moist soil, valley of the lower Rio Grande, Texas; common in northern Mexico and in the valley of the lower Colorado River, Arizona; widely distributed in Lower California; naturalized on Key West, the Bahamas, the West Indian islands, and in many other tropical countries.

Cultivated in most warm countries as an ornament of gardens, and to form hedges.

2. Parkinsonia microphylla Torr.

Leaves 1′ long, pale, densely tomentose when they unfold, pubescent at maturity, deciduous at the end of a few weeks; petiole ¼′ long; rachis short, rarely spinescent; leaflets in 4—6 pairs, distant, entire, sessile, broad-oblong or nearly orbicular, obtuse or somewhat acute at apex, oblique at base, ⅙′ long; stipules caducous. Flowers opening in May or early June before the leaves, on slender pedicels, in racemes 1′ or less long from the axils of leaves of the previous year, pale yellow; stamens longer than the petals. Fruit persistent on the branches for at least a year, frequently 1 or 2, rarely 3-seeded, 2′—3′ long, slightly puberulous, especially toward the base, with a long acuminate often falcate apex; seeds compressed, ⅓′ long, with a bright green embryo.

An intricately branched tree, occasionally 20°—25° high, with a trunk a foot in diameter, and stout pale yellow-green rigid branchlets terminating in a stout spine, covered at first with deciduous tomentum, slightly puberulous during their first and second seasons, and often marked by the persistent scales of undeveloped buds. Bark dark orange color, generally smooth, although sometimes roughened by scattered clusters of short pale gray horizontal ridges, becoming on old trees ¼′ thick; more often a shrub, frequently only a few feet tall. Wood heavy, hard, close-grained, dark orange-brown streaked with red, with thick light brown or yellow sapwood of 25—30 layers of annual growth.

Distribution. Deserts of southern Arizona and adjacent regions of California and Sonora, and in northern Lower California; known to attain the size and habits of a tree only in the neighborhood of Wickenburg, Maricopa County, Arizona.

10. CERCIDIUM Tul.

Trees or shrubs, with stout tortuous branches, covered with bright green bark and armed with slender straight axillary spines, and minute obtuse buds. Leaves alternate, abruptly pinnate, petiolate, early deciduous; pinnæ 2 or occasionally 3, 6—8-foliolate; stipules inconspicuous or 0; leaflets ovate or obovate, without stipels. Flowers perfect in short few-flowered axillary racemes, solitary or fascicled, with minute membranaceous early deciduous bracts; calyx 5-lobed, the lobes equal, acute, reflexed at maturity, their margins scarious, slightly revolute; petals orbicular or short-oblong, unguiculate, bright yellow, the upper petal broader and longer clawed than the others, slightly auriculate at base of the blade, the claw conspicuously glandular at base; stamens 10, inserted with the petals on the margin of the disk, free, slightly declinate, exserted; filaments filiform, pilose below, the upper filament enlarged at base and gibbous on the upper side; anthers uniform, ovoid, versatile; ovary short-stalked, inserted at the base of the calyx-tube; styles slender, involute, infolded in the bud, with a minute terminal stigma; ovules suspended from the angle of the ovary opposite the posterior petal. Legume linear-oblong, compressed or somewhat turgid, straight or slightly contracted between the seeds, thickened on the margins, the ventral suture acute, or slightly grooved, tipped with the remnants of the style, tardily dehiscent, 2-valved, the valves membranaceous or subcoriaceous, obliquely veined. Seeds suspended longitudinally on a long slender funicle, ovoid, compressed, the minute hilum near the apex; seed-coat thin, crustaceous; embryo compressed, light green, covered on the sides only by a thin layer of horny albumen; cotyledons oval, flat, rather fleshy; radicle very short, erect, near the hilum.

Cercidium is confined to the warmer parts of the New World, where it is distributed with four or five species from the southern borders of the United States through Mexico, Central America, and Venezuela to Mendoza. Of the three species found within the territory of the United States two are small trees.

Cercidium produces hard wood sometimes used as fuel.

The generic name, from κερκίδιον, refers to the fancied resemblance of the legume to the weaver’s instrument of that name.

CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES.

Legume compressed, with straight margins; leaflets green, slightly glandular. 1. C. floridum (E). Legume somewhat turgid, the margins often slightly contracted between the seeds; leaflets glaucous. 2. C. Torreyanum (G, H).

1. Cercidium floridum Benth. Green-barked Acacia.

Leaves 1′—1½′ long, with 2 or rarely 3 pinnæ, a broad pubescent petiole and rachis, and oval or somewhat obovate dull green puberulous minutely glandular leaflets about 1/16′ in length, rounded or slightly emarginate at apex, and when they unfold covered on the lower surface with scattered white hairs; petiolules short, stout, pubescent; appearing in April and deciduous in October. Flowers opening with the leaves, and produced in successive crops during three or four months, ¾′ in diameter, on slender pedicels, in 4 or 5-flowered racemes 1½′—2′ long, with small acute minute membranaceous caducous bracts. Fruit compressed, oblong, straight or slightly falcate, acute, narrowly and acutely margined on the ventral suture, glabrous, 2 or 3-seeded, 2′—2½′ long, ½′ broad, tardily dehiscent, the valves papery, yellow tinged with brown on the outer surface, and bright orange color within; seeds ⅓′ long.

A tree, 18°—20° high, with a short crooked trunk 8′—10′ in diameter, stout spreading branches covered with thin smooth bright green bark, forming a low wide head, and branchlets light or dark olive-green, slightly puberulous at first, soon glabrous, marked by occasional black lenticels, and armed with slender spines 1′ or less in length. Bark 1/16′ thick, light brown tinged with red, with numerous short horizontal light gray ridge-like excrescences. Wood light, soft, close-grained, pale yellow tinged with green, with thick lighter colored sapwood.

Distribution. Shores of Matagorda Bay to Hidalgo and Valverde Counties, Texas, and in northern Mexico; not common in Texas; very abundant and a conspicuous feature of vegetation in Mexico from the mouth of the Rio Grande to the foothills of the Sierra Madre.

2. Cercidium Torreyanum Sarg. Green-barked Acacia. Palo Verde.

Leaves few and scattered, 1′ long, hoary-tomentose when they first appear, puberulous at maturity, with a slender petiole and 2 pinnæ, with 2 or 3 pairs of oblong obtuse glaucous leaflets narrowed toward the somewhat oblique base, 1/12′—⅙′ long; unfolding in March and April and falling almost immediately when fully grown. Flowers ¾′ in diameter, on slender pedicels ¾′—1′ long, in 4 or 5-flowered racemes about 1′ in length, with small acute membranaceous caducous bracts. Fruit ripening and falling in July, 3′—4′ long, ¼′—⅓′ wide, 2—8-seeded, slightly turgid, often somewhat contracted between the seeds, frequently grooved on the ventral suture; seeds turgid, ⅓′ long.

A low intricately branched tree, leafless for most of the year, 25°—30° high, with a short often inclining trunk 18′—20′ in diameter, stout spreading branches covered with yellow or olive-green bark, forming a wide open irregular head, and glabrous slightly zigzag light yellow or pale olive-green and glaucous branchlets armed with thin straight or curved spines ¼′ long. Bark thin, smooth, pale olive-green, becoming near the base of old trunks reddish brown, ⅛′ thick, furrowed and separating into thick plate-like scales. Wood heavy, not strong, soft, close-grained, light brown, with clear light yellow sapwood.

Distribution. Sides of low cañons and depressions, and sandhills of the desert; valley of the lower Gila River, Arizona, to the Colorado Desert of southern California, and southward into Sonora and Lower California; when in flower in early spring the conspicuous and most beautiful feature of the vegetation of the Colorado Desert.

11. SOPHORA L.

Trees or shrubs, with minute scaly buds, unarmed terete branches prolonged by an upper axillary bud, and fibrous roots. Leaves unequally pinnate, with numerous small or few and ample thin or coriaceous leaflets; stipules minute, deciduous; stipels often 0. Flowers in terminal or axillary racemes, with linear minute deciduous bracts and bractlets; calyx broad-campanulate, often slightly turbinate or obconic at base, obliquely truncate, the short teeth nearly equal or the 2 upper subconnate and often somewhat larger than the others; disk cupuliform, glandular, adnate to the calyx-tube; corolla papilionaceous; petals white or violet blue, unguiculate; standard obovate or orbicular, usually shorter than the oblong, suberect keel-petals, as long or rather longer than the oblong-oblique wings, overlapping each other at the back, barely united; stamens free, or 9 of them slightly united at base, uniform; anthers attached on the back near the middle; ovary short-stipitate, contracted into an incurved style, with a minute truncate or slightly rounded capitate stigma; ovules numerous, suspended from the inner angle of the ovary, superposed, amphitropous. Legume terete, much contracted between the seeds, woody or fleshy, usually many-seeded, each seed inclosed in a separate cell, indehiscent. Seed oblong or oval, sometimes somewhat compressed; seed-coat thick, membranaceous or crustaceous; cotyledons thick and fleshy; radicle short and straight or more or less elongated and incurved.

Sophora is scattered over the warmer parts of the two hemispheres, with about twenty species of trees, shrubs or herbs; of the six North American species two are small trees. Several of the species produce valuable wood, and from the pods and flower-buds of the Chinese _Sophora japonica_ L., a dye is obtained used to dye white cloth yellow and blue cloth green. This tree is often cultivated as an ornament of parks and gardens in northern China, Japan, the eastern United States, and in western, central, and southern Europe.