262 MISC. PUBLICATION 423, U. S. DEPT. OF AGRICULTURE 



segments, opposite them; styles 2 or 3; ovary 1-celled; fruit a 1- 

 seeded utricle. 



This large family includes the cultivated sugar beet, garden beet, 

 and spinach. Many of the species are weeds, and some of them are 

 valuable for browse and grazing. Species of Atriplex and other 

 genera are characteristic plants of strongly saline and alkaline soils, 

 often taking up so much sodium chloride from the soil solution as to 

 give the herbage a distinctly salty taste. 



Key to the genera 



1. Embryo spirally coiled; leaf blades narrow, entire, either thick and fleshy or 

 spine-tipped (2). 

 2. Flowers without bractlets, monoecious, the staminate ones in catkinlike 

 spikes naked; perianth of the pistillate flowers confluent with the ovary. 



13. Sarcobatus. 



2. Flowers with a pair of bractlets and a perianth, mostly perfect, never in 



catkinlike spikes; perianth free from the ovary (3). 



3. Bractlets minute, scalelike, much shorter than the perianth; fruiting 



perianth scarcely enlarged, connivent, not winglike, remaining fleshy; 



plants mostly perennial, often suffrutescent; leaves soft and fleshy, 



subterete 14. Suaeda. 



3. Bractlets narrow, elongate, equaling or longer than the perianth; fruiting 

 perianth greatly enlarged, spreading, winglike, dry, scarious; plant 

 annual, becoming hard and prickly, the intricately branched stem 

 breaking off at the surface of the ground and becoming a tumble weed; 



leaves strongly spine-tipped 15. Salsola. 



1. Embryo not spirally coiled, circular to horseshoe-shaped, or conduplicate (4). 

 4. Leaves reduced to small scales; stems appearing jointed; flowers in dense, 



continuous, cylindric, fleshy spikes, perfect 12. Allenrolfea. 



4. Leaves with well-developed blades; stems not appearing jointed; flowers not 

 in dense, continuous, fleshy spikes (5). 

 5. Perianth segments strongly imbricate, nearly distinct; individual flowers 



relatively conspicuous; leaves opposite 1. Nitrophila. 



5. Perianth segments, if present, not or only slightly imbricate; individual 

 flowers inconspicuous; leaves all or most of them alternate (6). 

 6. Fruit at maturity naked; flowers perfect, in long slender spikes, without 

 bractlets, borne in the axils of conspicuous, scarious-margined bracts 



but not enclosed by them _, 11. Corispermum. 



6. Fruit at maturity enclosed bv the perianth or by the enlarged bractlets 



(7). 



7. Pubescence of the herbage pilose, villous, or lanate, the hairs simple 



and slender; flowers mostly perfect (8). 



8. Perianth in fruit not winged, bearing a dorsal tubercle or spine on 



each segment; plant annual; stem tall, much-branched; leaf 



blades linear, entire 9. Echinopsilon. 



8. Perianth in fruit with conspicuous, scarious, horizontal wings (9). 

 9. Plant annual; stems not tufted, much-branched; leaf blades thin 

 and flat, oblong, coarsely sinuate-dentate; wing of the 

 perianth annular, continuous or nearly so__ 3. Cycloloma. 

 9. Plant perennial; stems numerous, tufted, simple or sparingly 

 branched above; leaf blades thick, subterete, narrow, entire; 

 wingoftheperianthin5wedge-shapedsegments_ 10. Kochia. 

 7. Pubescence of the herbage wholly or partly of stellate, glandular, or 

 inflated hairs (the last collapsing and scurflike when dry), seldom 

 none; perianth, if any, not spiny or horizontally winged (10). 

 10. Flowers mostly perfect, without bractlets, with a perianth; 

 plants herbaceous (11). 

 11. Perianth segments and stamens 3 to 5; upper leaves of the in- 

 florescence usually much reduced 2. Chenopodium. 



11. Perianth segment and stamen one; upper leaves of the in- 

 florescence little reduced 4. Monolepis. 



