the family Cyperaceae, with usually solid stems, three-ranked 

 leaves, and closed leaf sheaths. 



Sedimentary Rock 



Rock formed from materials such as pebbles, sand, and 

 clay in rivers, lakes, and seas; usually in distinct layers, e.g., 

 conglomerate, sandstone, limestone. 



Sedimentation 



The process of depositing materials from a liquid, espe- 

 cially in bodies of water, cf. Sedimentary rock, Alluvium. 



Sediment Delivery Ratio (Percentage) 



The relation of the annual Sediment yield to the annual 

 gross amount of erosion. 



Sediment Yield 



The total sediment outflow from a watershed, includes 

 coarse and fine materials, bedload, and suspended materials; 

 a part of the gross erosion from an area. 



Seed 



The reproductive structure in Spermatophytes (flowering 

 plants and conifers) formed from the Ovule (q. v.), contain- 

 ing an Embryo, seed coat, and, in many kinds of plants, an 

 Endosperm. 



Seed Leaf 



See Cotyledon. 



Seedling 



A young plant produced from a seed. Usage in forest 

 nurseries; a tree which is still growing in the nursery, not 

 transplanted. Usage in forest reproduction; a tree grown 

 from seed and less than three feet in height. < 



Seed Plant 



A Spermatophyte (q. v.). 



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