114 



PERICARP. 



556. The acheniumJs a small, dry, indehiscent pericarp, free from 

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

 style (buttercups, Lithospermum). 



557. The double aehenium of the Umbeliferas, supported on a carpophore is called 

 cremocarp. The 2-carpeled aehenium of the Composite, usually crowned with a 

 pappus, is called cypsda. 



558. The achenia are often mistaken for seed3. In the Labiatae and Bor- 

 rageworts they are associated in fours (372). In Geum, Anemone, etc., they aro 

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

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



433 440 435 436 



434 437 4SS 439 



432, Achenia of Anemone thalietroides. 433, Cremocarp of Archangelica officinalis, its halve* 

 {meroearps) separated and suspended on the carpophore. 434, Cypsela of Thistle with its 

 plumous pappus. 435, Utricle of Chenopodium (pigweed). 436, Caryopsis of Wheat. 437. 

 Samara of Elm. 433, Glans of Beech. 439, Drupe of Prunus. 440, Fruit of Fragaria Indica, a 

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

 seeded pericarp, inseparable from the seed. 



561. Samara ; dry, 1-seedccl, 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, cither solitary (acorn, hazelnut) or several together (chestnut, 

 beechnut). 



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

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

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

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

 coats arc not distinguishable in the ovary. 



