503 ORDER ex. ULMACE^. 



Style I. Pistillate florets; perianth 2— 4-cleft. Style 1. Seed 

 1, inclosed by the perianth. 



1. P. Pknnsylva'nica, (Muhl.) Stem simple, erect, striate, pubescent. 

 Leaves alternate, linear-lanceolate, pubescent, witli opake dots, iw- 

 volucre S-K-aved. Flowers in compact, axillary clusters. Perianth ob- 

 long, persistent, inclosing the seed. — ^. June. Upper districts Car, 

 and Geo. 12 — 15 inches. Pellitory. 



2. P. Florida'na, (Nutt.) Stem decumbent, with erect branches, 

 pubescent near the summit. Leaves ovate, pubescent, dotted, some- 

 times nearly round. Flowers in axillary clusters. Leaves of the invo- 

 lucre nearly linear. — |^. May — Oct. Damp sandy soils. 12 — 18 in. 



Genus IV.— HU'MULUS. L. 20—5. 

 (From humus, fresh earth, from its choice of soil.) 



Flowers dioecious. Sterile florets in loose axillary panicles ; 

 perianth 5-parted. Stamens 5. Fertile florets ; scales of the 

 ament large, persistent, concave, entire, 1 -flowered. Perianth 

 none. Styles 2. Seed 1. 



1, H. Lu'puLUs, (L.) Stem twining, scabrous. Leaves opposite, 3 — 5- 

 lobed, scabrous, serrate. Sterile florets paniculate, axiUary, and termi- 

 nal ; fertile florets verticillate and sessile. — If. August. Hop- 



The amcnts of the fertile fJowers constitute Hops ; the useful, bitter principle of 

 which resides in resinous, glandular scales, surrounding the fruit. The pure substance 

 U called Lnpulin. 



Order CX.— ULMA'CE^. {Elm Family.) 



Flowers perfect or polygamous. Perianth divided, campan- 

 ulate, inferior. Stamens definite, 5 — 8, inserted into the base 

 of the perianth. Ovary superior, 1 -celled, with solitary pendu- 

 lous ovules. Stigmas 2, distinct. Fruit 1 — 2-ceIled, mem- 

 branaceous or drupaceous. Seed solitary, pendulous. Trees 

 or shrubs. 



Genus I— UL'MUS. 5—2. 

 (A Saxon word, elm or ulm.) 



Flowers perfect. Perianth carapanulate, 4 — 5 -cleft. Sta- 

 mens 5 — 8. Styles 2. F^ruit compressed, with a broad mem- 

 branaceous border. 



1. U. America'na, (Mich.) A large tree, with smooth, gracefully 

 recurved branches. Leaves alternate, lanceolate, oblique, doubly ser- 

 rate, with the serratures uncinate. Flowers 5 — 10, in a fascicle, pedi- 

 cel' ate. Fruit fimbriate. Styles 2, short Fruit 1 -seeded, surrounded 

 by a large, membranous wing. — ^, Feb. — March. Rich soils. 40 — 

 100 feet. White Elm, 



2. U. ful'va, (Mich.) A small tree. Leaves large, oval doubly ser- 

 iate, rough, sometimes slightly cordate, acuminate, pubescent* Flowers 



