BIRCH FAMILY. 



53 



Alnus glutinosa (L,.) Medic. Euro- 

 pean Alder. (Fig. 1223.) 



.etula Alnus %*ar. glutinosa L,. Sp. PI. 983. 1753. 

 Units glutinosa Medic. Pfl. Anat. 393. 1800. ' 



A tree, reaching a maximum height of about 

 75 and a trunk diameter of 2%, the bark 

 aooth, the branches nearly horizontal, the 

 oliage glutinous. Leaves broadly oval, orbicu- 

 or obovate, thick, dark green, dull, often 

 btuse at both ends, dentate and the teeth den- 

 culate, glabrous above, pubescent on the veins 

 eneath, 2'-$' loug; petioles ^'-i' long; 

 icnts appearing from naked buds, expanding 

 auch before the leaves, the staminate 3'-4' 

 ong, the pistillate ovoid-oblong, 6"-9" long 

 fruit; nut wingless, coriaceous-margined. 



In wet places, southern New York and New Jer- 

 t-y, escaped from cultivation and becoming natu- 

 ilized in a few localities. Native of Europe. Wood 

 oft, brown; weight per cubic foot 35 Ibs. April. 



5. Alnus maritima ( Marsh. > Muhl. 

 Seaside Alder. (Fig. ir 



ficlnla Alnus maritima Marsh. Arb. Am. ao. 1785. 

 Alnus maritima Muhl.; Nutt. Syh I 101. 



1865. 



A small tree, sometimes 30 tall and the trunk 

 6' in diameter, glabrous or very nearly so 

 throughout. Leaves oblong, ovate-oblong or 

 obovate, firm, acute at both ends, bright green 

 and shining above, pale green and dull beneath, 

 sharply serrulate, 2' '-4' long, i'-2' wide; petioles 

 3 // -io' / long; aments unfolding long after the 

 leaves, their buds developing during the season, 

 the staminate i / -2^ / long, the pistillate oblong, 

 9 // -i2 // long, 5 "-7" in diameter in fruit; nut ob- 

 long-obovate, wingless, coriaceous-margined. 



In wet soil, southern Delaware and eastern 

 land; also in the Indian Territory. Closely related 

 to A. Japonica of northeastern Asia, and perhaps tn >t 

 specifically distinct from it. Wood soft, light brown ; 

 weight per cubic foot 31 Ibs. Aug. -Sept. 



Family 7. FAGACEAE Drude, Phan. 409. 1879. 



BEECH FAMILY. 



Trees or shrubs. Leaves alternate, petioled, simple, dentate, serrate, lobed, 

 cleft or entire, pinnately veined, the stipules, if any, deciduous. Flowers small, 

 monoecious, the staminate in pendulous erect or spreading aments, or capitate, 

 the pistillate solitary or several together, subtended by an involucre of partly or 

 wholly united bracts, which becomes a bur or cup. Petals none. Staminaie 

 flowers with a 4~7-lobed perianth and 4-20 stamens; filaments slender, distinct, 

 simple; anther-sacs adnate, longitudinally dehiscent. Pistillate flowers with 

 lobed urn-shaped or oblong perianth, adnate to the 3~7-celled ovary: ovuU 

 in each cavity, only i in each ovary ripening, pendulous, anatropous; styles as 

 many as the cavities of the ovary, linear, terminally or longitudinally stigmntic. 

 Fruit a i -seeded nut, with a coriaceous or somewhat bony exocarp. Testa thin. 

 Endosperm none; cotyledons large, fleshy, often rugose; radicle short. 



About 5 genera and 375 species, of very wide geographic distribution. 



Staminate flowers capitate ; nut sharply triangular. I. Fagtts. 



Staminate flowers in slender aments; nut rounded or piano-con vt \ 



Pistillate flowers 2-5 in each involucre; involucre Becoming globose and very prickly in fruit, 



enclosing the nuts. 2. Ca.\tanfa. 



Pistillate flower i in each involucre; involucre of numerous scales forming a cup in fruit and 



subtending the acorn. 3- Quercus. 



