THE DRUPE-FRUITS 141 



inch long, slender, pubescent, tinged with red; glands few or glandless. 

 Flowers 1 inch or less in size; borne in lateral umbel-like clusters, 1, 2 or 

 rarely 3 from a bud; calyx-tube campanulate, glabrous, tinged with red. 

 Fruit globular or oval, often necked, less than 1 inch in diameter, bluish- 

 black or amber-yellow, with a heavy bloom ; skin thin, tough ; stem slender, 

 y^ inch long; cavity shallow, narrow; apex roundish or flattened; suture 

 indistinct or a line; flesh firm, yellow, juicy, sweet or acid; stone clinging 

 or free, turgid, ovoid, smooth, ridged on one edge and grooved on the other. 



199. Insititia distinguished from Domestica plums. — The In- 



sititia plums are readily distinguished from the Domestica sorts 

 in having" a dwarfer and more compact habit of growth ; smaller 

 and more ovate leaves, with more closely serrate margins; 

 branches more slender, with shorter joints, and bearing spines- 

 cent spurs; a more abundant and a more clustered inflorescence, 

 with smaller flowers; a glabrous instead of a pubescent pistil 

 and calyx-tube ; reflexed calyx-lobes, whereas in Domestica they 

 are often erect ; and flowers which appear nearly a week later. 

 The fruits are smaller, more nearly round or oval, more uniform 

 in shape and never strongly compressed as in Domestica, with a 

 less distinct suture and more often wdth a pronounced neck. 

 The color is usually the Damson purple or the Mirabelle yellow, 

 with no intermediate colors as in Domestica. The plums are 

 sweet or sour, and have a very much smaller range in flavor in 

 the Insititias. The stones are smaller, more oval, and much 

 more swollen. 



Insititia plums are much less variable than the Domesticas. 

 These plums have been cultivated over two thousand years, yet 

 there is seemingly little difference between the sorts described 

 by the Greeks and Romans at the beginning of the Christian 

 Era and those now grown. Also, one often finds half-wild 

 chance seedlings with fruit indistinguishable from varieties 

 under the highest cultivation. This pronounced immutability 

 of the species is one of its chief characteristics. 



200. Habitat and history of Insititia plums. — Wild plums of 

 this species are found in nearly all temperate parts of Europe 

 and Western Asia, probably as escapes from cultivation except 

 in southeastern Europe and the adjoining parts of Asia. The 

 recorded history of the Insititia plums is older than that of the 

 Domesticas, going back to the sixth century B. C. Pliny, the 

 Roman naturalist of Christ's time, wrote of an Insititia under 



