acuminate, with thickened greenish midnerve and wide scarious margins, roughened 

 on the keeled midnerve; petals 5, white, oblong, shorter than the sepals; stamens 

 5 or 10; fruit subglobose, 2-3 mm. in diameter, firm-textured, 5-carpellate; seeds 

 glossy, light-brown, elliptic-oblong, curved, obscurely reticulate. 



In ditches, swamps, marshes and on mud about ponds and on wet banks in 

 Okla. (Waterfall) and s. Tex., June-Oct.; from Ark. to Tex. and s. Calif., n. to 

 s. 111., Mo., S.D. and Wash. 



Fam. 91. Tamaricaceae Link. Tamarisk Family 



Shrubs or small trees; leaves alternate, exstipulate, sessile, small and scalelike, 

 entire, commonly imbricated; flowers mainly perfect, regular, in spicate racemes 

 that are usually collected to form a panicle; sepals 4 or 5, imbricated; petals 4 or 

 5, distinct, somewhat imbricated; disk 5- or 10-lobed or obsolete; stamens 4, 5, 8 

 or 10, the distinct filaments free, the anthers opening lengthwise; ovary 1 -celled, 

 superior, with 3 to 5 basal placentae; stigmas 2 to 5, distinct; ovules 2 to many on 

 each placenta; fruit a capsule; seeds erect, terminating in a sessile tuft of hairs. 



More than 60 species in four genera, all natives of the Old World. 



1. Tamarix L. Tamarisk. Salt Cedar 



Deciduous shrubs or small trees with irregularly and widely spreading slender 

 terete stems; the ultimate small branchlets deciduous with the leaves; leaves clasp- 

 ing or sheathing; flowers small, short-pediceled or sessile; petals pink or white, 

 inserted under the disk; capsule dehiscent into 3 to 5 valves; seeds numerous. 



About 50 species in the Old World, many of which are cultivated for their 

 feathery foliage and profuse pink or white flowers. Occasionally planted for wind- 

 breaks and for sand binding. Most have become naturalized in such places as 

 along rivers, streams and irrigation ditches (especially if saline), about lakes, in 

 and about salt flats and in waste places generally. They flower periodically through- 

 out the year. 



These attractive and ornamental flowering trees and shrubs provides abundant 

 shade and are excellent honey plants. In some regions they are considered to be 

 beneficial in preventing too rapid run-off after heavy rains. Because of their toler- 

 ance to alkaline and saline conditions, they are valuable as shade and ornamental 

 plants in such areas. In many regions, such as along the Pecos River, they have 

 become a rather serious problem because of having formed extensive stands along 

 its banks with consequent great loss of water from this important water course. 



Adapted from Bernard R. Baum in Baileya 15(1 ) : 19-25. 1967. 



1. Flowers 4-merous, occasionally with more than 4 stamens 5. T. parviflora. 



1. Flowers 5-merous, occasionally with more than 5 stamens (2) 



2(1). Staminal filaments arising from the alternating disk-lobes (3) 



2. Staminal filaments not as above (4) 



3(2). Racemes mostly on last year's branches, 6-9 mm. broad (in dried material); 

 petals ovate to broadly truUiform-ovate, more than 2 mm. long 

 1. T. africana. 



3. Racemes mostly on green branches, 4-5 mm. broad; petals elliptic to some- 



what ovate-elliptic, less than 2 mm. long 4. T. gallica. 



4(2). Staminal filaments inserted between the more or less retuse lobes of the 

 disk; petals caducous (sometimes 1 or 2 persisting). ...2. T. aphylla. 



4. Staminal filaments as above but with at least 3 of them inserted under the 



disk near the margin; petals persistent after maturity (5) 



1148 



