CORYLOPSIS 



CORYLUS 



859 



AA. Fls. in 2-3-fld. racemes. 



pauciflora, Sieb. & Zucc. Low, much-branched shrub, 

 2-3 ft. : Ivs. obliquely cordate, ovate, sinuate-dentate, 

 ciliate, pubescent and glaucous beneath, 1-2 in. long: 

 racemes 2-3-fld., H~Min. long; fls. light yellow; petals 

 obovate, about as long as stamens and style. Japan. 

 S.Z. 20. G.F. 5:342. Gt. 48:1467. BM. 7736. G.W. 

 15, p. 101. J.H. III. 48:381. S.I.F2:26. 



C. Grlffithii, Hemsl. (C. himalayana, Hook., not Griff.). Shrub 

 or small tree, to 20 ft.: young branchlets and Ivs. beneath densely 

 pubescent: Ivs. subcordate: racemes 1-2 J^ in. long; stamens and 

 styles much shorter than the obovate petals. Himalayas. B.M. 



6779. 



ALFRED REHDER. 



CORYLUS (ancient Greek name). Betulacese. 

 HAZEL. FILBERT. COBNUT. Woody plants grown for 

 their handsome rather large foliage and some species 

 for their edible nuts. 



Deciduous shrubs, rarely trees: Ivs. alternate, stipu- 

 late, petioled, serrate and usually more or less pubes- 

 cent: fls. mono3cious, appearing before the Ivs.; stam- 

 inate in long, pendulous catkins, formed the pre- 

 vious year, and remaining naked during the winter 

 (Fig. 1073), each bract bearing 4 divided stamens; pis- 

 tillate included in a small, scaly bud with only the red 

 styles protruding (Fig. 1074) : fr. a nut, included or sur- 

 rounded by a leafy involucre, usually in clusters at the 

 end of short branches. Fifteen species in N. Amer., 

 Eu. and Asia, all mentioned below. Monograph by 

 Winkler in Engler, Pflanzenreich, hft. 19, pp. 44-56 

 (1904), quoted below as Winkl. 



Numerous varieties are culti- 

 vated in Europe for their edible 

 nuts. They are also valuable for 

 planting shrubberies, and thrive in 

 almost any soil. The foliage of 

 some species turns bright yellow or 

 red in autumn. Propagated by 

 seeds sown in fall, or stratified and 

 sown in spring; the varieties usually 

 by suckers, or by layers, put down 

 in fall or spring; they will be rooted 

 the following fall. Budding in sum- 

 mer is sometimes practiced for 

 growing standard trees, and graft- 

 ing in spring in the greenhouse for 

 scarce varieties. They may also be 

 increased by cuttings of mature 

 wood taken off in fall,^kept during 

 the winter in sand or moss in a cellar 

 and planted in spring in a warm 

 and sandy soil. Illustrated mono- 



graph of the cultivated varieties 

 y Franz Goeschke, Die Haselnuss 

 (1887). See, also, bulletin on Nut- 

 culture by the U. S. Dept. of Agric. For the culture of 

 the nuts, see articles Filberts and Hazels. 



1073. Winter catkins 

 of filbert. 



americana, 7. 

 atropurpurea, 4. 

 aurea, 4. 

 Avellana, 4, 8. 

 californica, 12. 

 calyculata, 7. 

 chinensis, 3. 

 Colurna, 2, 3. 

 Crista-Galli, 6. 



INDEX. 



ferox, 1. 

 fusco-rubra. 4. 

 glandulifera, 2. 

 heterophylla, 4, 6. 

 laciniata, 4. 

 mandshurica, 9. 

 maxima, 8. 

 pendula, 4. 



pontica, 5. 

 purpurea, 8. 

 rostrata, 9, 10, 11, 12. 

 Sieboldiana, 10. 

 setchuenensis, 6. 

 thibetica, 1. 

 tubulosa, 8. 

 yunncmensis, 6. 



A. Husk or involucre consisting of 2 distinct bracts 



(sometimes partly connate). 

 B. Involucre densely spiny: Ivs. nearly glabrous. 

 1. ferpx, Wall. Tree, to 30 ft.: young branchlets 

 silky-hairy: Ivs. oblong to obovate-oblong, usually 

 rounded at the base, acuminate, doubly serrate, gla- 

 brous except on the veins beneath, with 12-14 pairs of 

 veins, 3-5 in. long: involucre tomentose, forming a 

 spiny bur about 1% in. across, longer than the small 

 nuts. Himalayas. Winkl. 45. Var. thibetica, Franch. 



55 



(C. thibetica, Batal.). Lvs. broadly ovate to obovate: 

 involucre glabrescent. Cent, and W. China. R.H. 

 1910:204. 



BB. Involucre not spiny. 



c. Bracts of the involucre deeply divided into linear lobes, 

 much longer than the nut: tree. 



2. Colurna, Linn. Tree, to 70 ft.: petioles %-2 in. 

 long, usually glabrescent: Ivs. deeply cordate, roundish 

 ovate to obovate, slightly lobed and doubly crenate- 

 serrate, at length nearly glabrous above, pubescent 

 beneath, 3-5 in. long: frs. 3-10, clustered: involucre 

 open at the apex, usually densely beset with glandular 

 hairs: nut roundish ovate, %in. long. From S. Eu. to 

 Transcaspia. G.C. III. 40:256. Gn. 31, pp. 260-1. 

 H.W. 2, p. 29. G.W. 14, p. 642. Gng. 16: lei-Orna- 

 mental tree, with regular pyramidal head, not quite 

 hardy N. Rarely cult, for the fr. under name of filbert 

 or of Constantinople or Constantinople nut. Var. glan- 

 dulifera, DC. Petioles and peduncles glandular-setose: 

 lobes of the involucre less acute and more dentate. 



3. chinensis, Franch. (C. Colurna var. chinensis, 

 Burk.). Tree, to 120 ft.: petioles J^-l in. long, pubes- 

 cent and setulose: Ivs. ovate to ovate-oblong, cordate 

 and very oblique at the base, glabrous above, pubes- 

 cent on the veins beneath, doubly serrate, 4-7 in. long: 

 fr. 4-6, clustered; involucre constricted above the nuts,, 

 with recurved and more or less forked 



lobes, finely pubescent, not glandular. 

 W. China. Winkl. 49 and 50. 



cc. Bracts of the involucre divided into 



lanceolate or triangular lobes: shrubs. 

 D. The involucre not or only slightly longer 

 than the nut, open or spreading at 

 the apex. 

 E. Lobes of bracts serrate or dentate. 



4. Avellana, Linn. Shrub, to 15 ft.: 

 Ivs. slightly cordate, roundish oval or 

 broadly obovate, doubly serrate and often 

 slightly lobed, at length nearly glabrous 

 above, pubescent on the veins beneath: 

 involucre shorter than the nut, deeply 

 and irregularly incised: nut roundish 

 ovate, K~/4in. high. Eu., N. Afr.,W. Asia. 

 H.W. 2:16, p. 28. Var. atropurpilrea, 

 Kirchn. (var. fusco-rubra, Goeschke). 

 Lvs. purple. Var. aurea, Kirchn. Lvs. 

 yellow. Var. laciniata, Kirchn. (var. 

 heterophylla, Loud.). Lvs. laciniately in- 

 cised or lobed. Var. pendula, Goeschke. 

 With pendulous branches. G.W. 2, p. 

 13. There are also many varieties cult, 

 for their fr. 



5. pontica, Koch. Shrub: Ivs. cordate, 

 roundish ovate or broad-oval, doubly ser- 

 rate, pubescent 'beneath: involucre finely pubescent, 

 with few glandular hairs at the base, campanulate, 

 somewhat longer than the nut, with large spreading 

 lobes: nut large, broad-ovate. W. Asia. F.S. 21 : 2223-4 

 (as C. Colurna). From this species the cobnuts seem 

 to have originated; also the Spanish nuts are probably 

 mostly cross-breeds between this species and C. Avellana 

 or C. maxima, or between the two latter species. 



EE. Lobes of the bracts entire or sparingly dentate, 

 triangular. 



6. heterophylla, Fisch. Shrub, to 12 ft.: petioles 

 about %in. long: Ivs. orbicular-obovate, cordate at the 

 base, nearly truncate at the apex and with a very short 

 point, incisely serrate, pubescent on the veins beneath, 

 2-4 in. long: involucre somewhat longer than the nuts, 

 striate, glandular-setose near the base. Japan to W. 

 China. S.I.F. 1 : 20. Several varieties apparently not yet 

 in cult, occur in China: var. Crista-Galli, Burkill, var. 

 setchuenensis, Franch., and var. yunnanensis, Franch. 



1074. Pistillate 



flowers of 



Corylus rostrata. 



(Natural size; 



