114 



PERICARP. 



556. The achenium is a small, dry, indehiscent pericarp, free from 

 tte one seed which it contains, and tipped with the remains of the 

 style (buttercups, Lithospermum). 



557. The double achenium of the Umbeliferse, supported on a carpophore is called 

 cremocairp. The 2-carpeled achenium of the Compositae, usually crowned with a 

 pappus, is called cypsela. 



558. The aohenia aee opieit mistaken for seeds. In the Labiatas and Bor- 

 rageworts they are associated in fours (312). In Geum, Anenaone, etc., they are 

 collected in heads. The rich pulp of the strawberry consists wholly of the over- 

 grown receptacle, which bears the dry aohenia on its surface. (440). 



484 43T 48S 439 



4S2, Aohenia of Anemone thaliotroides. 433, Cromocai-p of Arohangclica officinalis, its hnlyej 

 {merooarps) separated anil suspended on tlio carpophore. 434, Cypsela of Tliistle with its 

 plumous pappus. 435, TJti'iole of Clionopodium (pigweed). 436, Cavyopsis of Wheat. 43T, 

 Samara of Elm. 438, Glans of Beech. 439, Drupe of Prunus. 410, Fruit of Fragaria Indica, u 

 fleshy torus like the strawberry. 



559. The utricle is a small, thin, pericarp fitting loosely upon its 

 one seed, and often opening transversely to discharge it (pigweed, 

 prince's feather). 



560. Cabyopsis, the grain or fruit of the grasses, is a thin, dry, 1- 

 seeded pericarp, inseparable from the seed. 



561. Samara ; dry, 1-seeded, indehiscent, furnished with a mem- 

 branous wing or wings (ash, elm, maple). 



562. Glans or nut ; hard, dry, indehiscent, commonly 1-seeded by 

 suppression (§ 545), and invested with a persistent involucre called a 

 cupule, either solitary (acorn, hazelnut) or several together (chestnut, 

 beechnut). 



563. Drupe, stone-fruit ; a 3-coated, 1-celled, indehiscent pericarp, 

 exemplified in the cherry, peach. The outer coat (epidermis) is called 

 the epicarp, the inner is the nucleus or endocarp, hard and stony ; the 

 intervening pulp or fleshy coat is the sarcocarp (aap^, flesh). These 

 coats are not distinguishable in the ovary. 



