142 NATURAL HISTORY OF PLANTS. 



and its superior radicle is rectilinear. There are Elms with flowers 

 having six, seven or eight divisions. — They are trees or shrubs,^ of 

 which some fifteen sjoecies are known,^ inhabiting the temperate 

 regions of the northern hemisphere of both worlds. The branches 

 are often snberose and sometimes alate. The leaves (fig. 89) are 

 alternate, distichous, simple, often serrate, penninerved, unsym- 

 metrical at the base,^ accompanied with lateral stipules. The leaves 

 almost always fall in winter, and it is before their development that 

 the numerous, inconspicuous flowers* show themselves emerging 

 from axillary scaly buds, and arranged in cymes or glomerules more 

 or less compound. 



In India there is an Elm, Ulmus integrifolia^ the sepals of which 

 are free and its androecium diplostemonous. Its embryo instead of 

 being flat has two conduplicate cotyledons. It has been made a 

 genus under the name of Holoptelea, Another tree, growing in the 

 marshes of North America, which the older botanists placed in the 

 Elm genus, has the flowers of this genus with the foliage of certain 

 Hornbeams ( Carpinus) ; but its dry indehiscent fruit has a thin 

 mesocarp, dilated on every side into soft and papillose lamellae or 

 points ; characters which distinguish the geims Flanera, Ahelicea^ 

 formerly classed among the Elms, afterwards with Planera^ has its 

 habit, foliage and flowers ; but the fruit, at flrst drupaceous, then 

 with mesocarp withered and thin, is of smooth surface. It terminates 

 in a small recurved beak ; which gives it some resemblance to a 

 retort with a full body and very short neck. It is traversed on 

 one side by a marginal crest, not very prominent in most species 

 which are natives of Crete, the Caucasus, and Eastern Asia, but 

 developed more to a wing in Z. Bavidii^ a tree of northern China, 

 of which a genus has also been made under the name Hemiptelea. 



The Lotus trees (^ Celtis) constitute a distinct subseries, charac- 

 terised chiefly by a drupaceous fruit (fig. 97). That is the general 

 character of a group which has been raised to the rank of even a sub- 

 order ( Celtidece). Their flowers (fig. 95, 96) are polygamo-monoecious 



^ P1.ANCHON divides the genus into 3 sections Sort. Berol. 295. — Michx. M. Bor. Atnei'. i. 172 



(or sub-genera) : 1 Oreoptelea (Spach) ; 2 Bryo- — With. Arrang. ii. 275. — Koxb. Fl. Ind. ii. 



ptelea (Spach) ; 3 Micropielea (Spach) founded 67. — Nutt. Trans. Amer. Phil. Soc. n. ser. v. 



on the form of the perianth, the time ofap- 169. — Sond. Regensb. Flora (1851), 43. — A 



pearance of the flowers, the form and position Gray, Man. ed. 5, 442. — Chapm. Fl. S. Unit. St. 



of the pedicel, the ciliation or otherwise of the 416, Gren, et Godr. Fl.de Fr. iii. 105. — 



margins of the samara. Walp. Ann. iii. 424. ^ 



• - FouGER. Mem. Acad. Sc. Far. (1787), t. 2. ' The internal half is the larger. 



— J ACQ. Sort. Sckoenbr. t. 261. — W. Enum. * Green, yellowish or reddish. 



