cupulifEr^. (oak family.) 473 



§ 1. F/oirers developed in spring with the frurrs : tin- sterile from catkins which 

 have remained naked over ivinter ; while the fertile have been enclosed in a 

 scaly bud ; fruit with a conspicuous thin wing, as in Birch. 



1. A. viridis, DC. (Gkeen or Motntain Alder.) Shrub 3-8° high; 

 leaves rouud-oval, ovate, or slightly heart-shaped, glutinous and smooth or 

 softly downy beneath, irregularly serrulate or biserrulate with very sharp and 

 closely set teeth, sometimes sinuate-toothed and serrulate (var. sixiXta 

 Kegel), on young shoots often cut-toothed ; fertile catkins slender-stalked, 

 clustered, oVoid (6-8" long). — On mountains and mountain streams, Newf. 

 to W. Mass., N. Y., L. Superior, and far north and west; also in the Alle- 

 ghanies to N. C. (Eu., Asia.) 



§ 2. Flowers developed in earliest spring, before the leaves, from mostli/ clustered 

 catkins ichich {of both sorts) were formed the foregoing summer and have re- 

 mained naked over winter ; fruit wingless or with a narrow coriaceous margin. 



2. A. incana, Willd. (Specki.kd or Hoahy a.) Leaves broadli/ oval 

 or ovate, rounded at base, sharply and often doubly serrate, irhitened and mosdq 

 downy beneatli ; stipules oblong-lanceolate; fruit orl)icular. — Borders of 

 streams and swamps, Newf. to Mass., E. Neb., Minn., and westward. Shrulj 

 or tree 8-20° high ; the common Alder northward. (Eu., Asia.) 



3. A. serrulata, Willd. (Smooth A.) Leaves obovate, acute at base, 

 sharply serrate with minute teeth, thickish, green both sides, smooth or often 

 downy beneath ; stipules oval ; fruit ovate. — Borders of streams and swamps, 

 Mass. to Fla., west to S. E. Minn, and Tex. ; common. Shrub forming dense 

 thickets, or sometimes at the south a small tree 6 -.3.5° high. 



§ 3. Flowers in autumn (Sept.) from catkins of the season ; the fertih mostlif soli- 

 tar ij in the axils of the leaves, ripening the fruit a year later ; fruit wingless. 



4. A. maritima, Muhl. (Sea-side A.) Glabrous; leaves oblong, ovate. 

 or obovate with a wedge-shaped base, slender-petioled, sharply serrulate, bright 

 green, or rather rusty beneath ; fruiting catkins large, ovoid or oblong (9 - 12" 

 long, 6" thick). — Borders of streams and swamps. S. Del. and E. Md., near 

 the coast. Small tree 1.5-2.5° high. {l\. Asia.) 



3. CdRYLUS, Tourn. Hazel-nit. Filbert. 



Sterile flowers in drooping cylindrical catkins, consisting of 8 (half-) stamens 

 with 1-celled anthers, their short filaments and pair of scaly bractlets cohering 

 Miore or less with the inner face of the scale of the catkin. Fertile flowers sev- 

 eral in a scaly bud, each a single ovary in the axil of a scale or bract, and ac- 

 companied by a pair of lateral bractlets ; ovary tipped with a short limb of the 

 adherent calyx, incompletely 2-celled, with 2 pendulous ovules, one of them 

 sterile ; style short ; stigmas 2, elongated and slender. Xut ovoid or oblong, 

 bony, enclosed in a leafy or partly coriaceous cup or involucre, consisting of 

 the two bractlets enlarged and often grown together, lacerated at the border. 

 Cotyledons very thick (raised to the surface in germination), edible; the short 

 radicle included. — Shrubs or small trees, with thinnish doubly-toothed leaves, 

 folded lengthwise in the bud, flowering in early spring; sterile catkins single 

 or fa.scicled from scaly buds of the axils of the preceding year, the fertile ter- 



