612 



TREES OF NORTH AMERICA 



and summer, and in the tropics throughout the year, on slender pedicels ~ 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 \'-\ r in length, in graceful racemes, 2'-4' long, long-pointed, 

 dark orange-brown, slightly pilose, compressed between the remote seeds; seeds \' long, 

 nearly terete, with thick albumen and a bright yellow embryo. 



A tree, 18-SO 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 f ' thick, brown tinged with 

 red, the generally smooth surface broken into small persistent plate-like scales. Wood 



Fig. 560 



heavy, hard, close-grained, with very thick lighter colored sapwood tinged with yellow. 



Distribution. Low r moist soil, valley of the lower Bio Grande, Texas; common in 

 northern Mexico and in the valley of the lower Colorado River, Arizona; widely distrib- 

 uted 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 j' 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, ' 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, %' 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, gen- 



