Excerpta Botanica. 351 



ner either terminated by a gland or not ; that the involucre is 

 sometimes shorter than, sometimes as long as, and sometimes 

 longer than the nut ; that nevertheless it rarely exceeds the 

 nut by more than one-third, whilst in C. Colurna the nut is 

 often two to three times shorter than the involucre ; and lastly, 

 that the segments of this involucre, slightly inciso-dentate in 

 certain varieties, are, on the contrary, more or less deeply 

 palmatifid in other varieties, not only in those in cultivation, 

 but also in those which are very common in woods ; and in 

 this latter case the secondary segments {lanieres secondaires) 

 are sometimes equal, sometimes more or less unequal, very 

 entire, or jagged, or inciso-dentate, or pinnatifid ; in form sub- 

 linear, or linear-lanceolate, or lanceolate, or semi-lanceolate, 

 or oblongo-lanceolate, or suboval, or deltoid, and sometimes 

 acute, soinetimes acuminate. 



The more notable modifications of the fructiferous invo- 

 lucre afford the following varieties : — 



a, brachychlamys, Spach. — Corylus Avellana sylvestris et Cory his 

 Avellana ovata, Willd. — Involucre a little shorter or a little 

 longer than the nut ; segments irregularly inciso-dentate ; nut 

 obovate, or oval, or oblong; involucre pubescent, or hispid, 

 glandular, or non-glandular, 'i'his variety appears to be com- 

 moner than all the others in the woods. 

 /3. schizochlamys, Spach; — Involucre generally as longas, or about ird 

 longer than the nut ; segments palmatifid as far as the middle or 

 beyond ; straps {lanieres) chiefly jagged or inciso-dentate. Nut 

 variable in form. Involucre sometimes hispid and glandular, 

 sometimes only pubescent with or without glands. This variety 

 is common in the woods in the environs of Paris, 

 y. macrochlamys, Spach. — Corylus Avellana glomerata, Hort. Kew. 

 — Corylus Avellana maxima, A\xd\b.Cdit. Involucre large (often 

 about 18 lines long and as many broad), one-half longer than 

 the nut ; segments palmatifid ; straps {lanieres) inciso-dentate, 

 or subpinnatifid, broad, acute. Nut large, subglobose. Culti- 

 vated variety. 



2. cylindrochlamys, Spach. — Corylus Avellana grandis, Hort. Kew. 



Corylus Avellana maxima, Willd. Involucre ( 1 5 — 1 8 lines long) 

 subcylindrical, a little longer than the nut ; segments inciso- 

 dentate atthe summit. Nut obovate or subglobose, or ellipsoid, 

 very large. Cultivated variety known by the name of Filbert. 

 Of the numerous variations of the leaves of this species, the 

 two following alone merit special notice : — 



Corylus Avella?ia urtica/olia, Audib. Cat, — Corylus laciniata et Co- 

 rylus urticcpfolia, Hortul. Leaves deeply sinuato-])innatifid ; 

 segments acute, inciso-dentate. 

 Corylus Avellana crispa. Loud. — Corylus crispa, Hortul. Leaves 

 inciso-angular and crisped. 



