206 CLASS XII. ORDER II. 



year's branches, in numerous umbels of from two to five flowers. 

 Peduncles short, filiform, pubescent under a magnifier as well as 

 the calyx. Corolla small, white. Fruit large, globular, eatable, 

 with the flavor of the common plum. — Always near the salt 

 water; abundant on Plum island.— May. — Fruit ripe in August 

 and September. 



Variety «. Fruit an inch in diameter, purple, with a glaucous 

 bloom. 

 (9. Fruit similar, but smaller. 

 y. Fruit crimson, shining. 

 This is our common Beach plum, much prized for its agreeable 

 fruit, and deserving attempts at cultivation. I do not find it cer- 

 tainly described by any author, unless possibly by Michaux, 

 under the name of P. spha^rocarpa, a name previously appropria- 

 ted by Swartz to a AVest Indian species. From P. viaritima of 

 Pursh it appears widely different in its inflorescence, acumina- 

 tion, and fruit. Dr. Torrey, and some others, consider it the 

 P. pubescens of Pursh, from whose description it seems to me to 

 diflter. 



DIGYNIA. 

 216. CRAT^GUS. 

 Crat^gus crus galli. L. Common Thorn Bush. 



Thorny ; leaves obovate, subsessile, shining, coria- 

 ceous ; leafets of calyx lanceolate, subserrate. Ait. abr. 



A strong, branching, thorny shrub. Leaves inversely ovate, 

 sharply and irregularly serrate, sometimes cleft, tough, smooth. 

 Thorns two or three inches long, rigid, acute. Flowers white, 

 in terminal corymbs. Calyx leaves linear. — About fences and 

 thickets. — May, June. There are several varieties of this 

 species. 

 Crataegus coccinea. L. Red Thorn. 



Thorny; leaves on long petioles, ovate, subcordate, 

 acutely lobed and serrate, smooth; calyx pitbescent, 

 glandnlar; styles five. 



A large shrub with a few long spines. Flowers in corymbs, 

 white. Fruit rather large, red, eatable. — Sudbury. — May. 



