628 



ULMACEAE. 



VOL. I. 



2. PLANERA J. F. Gmel. Syst. 2: Part i, 150. 1791. 



A tree, similar to the elm, the flowers monoecious or polygamous, unfolding with the 

 leaves. Staminate flowers fascicled on twigs of the preceding season, the pistillate or per- 

 fect ones in the axils of the leaves of the year. Calyx 4-5-cleft, campanulate, persistent, the 

 lobes imbricated. Filaments filiform, straight, exserted. Ovary stalked, ovoid, slightly 

 compressed, i-celled. Styles 2, spreading, stigmatic along the inner side. Fruit nut-like; 

 coriaceous, obliquely ovoid, compressed, ridged on the back, covered with short fleshy proc- 

 esses. Embryo straight. [Name in honor of Johann Jakob Planer, 1743-1789, Professor 

 of Botany in Erfurt.] 



A monotypic genus of southeastern North America. 



i. Planera aquatica (Walt.) J. F. Gmel. 

 Planer-tree. Water Elm. Fig. 1544. 



Anonymos aquatica Walt. Fl. Car. 230. 1788. 

 Planera aquatica J. F. Gmel. Syst. 2: Part i, 150. 

 1791. 



A small tree, sometimes 40 high, and with 

 a trunk 2 in diameter, the foliage nearly gla- 

 brous. Leaves ovate or oblong-lanceolate, 

 acute at the apex, obtuse or cordate and usu- 

 ally somewhat inequilateral at the base, ser- 

 rate, i'-2' long; petioles \\"-2" long; stipules 

 lanceolate, about as long as the petioles, de- 

 ciduous ; staminate flowers fascicled and some- 

 what racemose from scaly buds borne at the 

 axils of leaves of the preceding season ; per- 

 fect or pistillate flowers on short branches; 

 fruit 2"-3" long, about equalling its stalk, its 

 soft processes ' long. 



In swamps, Missouri to southern Indiana, Ken- 

 tucky and North Carolina, south to Texas and 

 Florida. Wood soft, weak, compact, light brown ; 

 weight per cubic foot 33 Ibs. April-May. Syca- 

 more. (N. C.) 



3. CELTIS (Tourn.) L. Sp. PI. 1043. 1753- 



Trees or shrubs, with serrate or entire pinnately veined or in some species 3~5-nerved 

 leaves, and polygamous or monoecious (rarely dioecious?) flowers, borne in the axils of 

 leaves of the season, the staminate clustered, the fertile solitary or 2-3 together. Calyx 

 4-6-parted or of distinct sepals. Filaments erect, exserted. Ovary sessile. Stigmas 2, 

 recurved or divergent, tomentose or plumose. Fruit an ovoid to globose drupe, the exocarp 

 pulpy, the endocarp bony Seed-coat membranous. Embryo curved. [Name ancient, used 

 by Pliny for an African Lotus-tree.] 



About 60 species, of temperate and tropical regions. Besides the following, some three others 

 occur in southern and western North America. Type species : Celtis australis L. 



Leaves thin, not strongly reticulate-veined beneath. 



Pedicels mostly twice as long as the drupe, or longer ; leaves large. 

 Leaves ovate to ovate-lanceolate, drupe 4"-s" in diameter. 

 Leaves smooth or nearly so above. 

 Leaves very rough above. 



Leaves lanceolate to ovate-lanceolate ; drupe 3" -4" in diameter. 

 Pedicels short, often little longer than the drupe ; leaves small. 

 Leaves thick, coriaceous, strongly reticulate-veined beneath. 



1. C. occidentalis. 



2. C. crassifolia. 



3. C. mississippiensis. 



4. C. georgiana. 



5. C. reticulata. 



