Abstract:

This is the second paper under the same topic (cf. Bull. Bot. Res.6(2): 101-

106, 1986) as materials for compiling Fl. Reip. Pop. Sin.

      There are 7 species of Fagus found in China, but whether two of them, F. tientaiensis, F.

chienii, can stand steadily or not is doubtful. Lacking sufficient available materials at hand,

the matter would better be left for a further study.

      F. hayatae, F. pashanica and F. tientaiensis are so closely alike among them that differen-

ces seem exist only in quantitive characters such as size of leaves, duration of indumentum and

less gap in length of the cupules and their peduncles.  Considering some criteria, they may be

treated as geographical races belonging to a single species.

      Diverse morphological interpretations concerning the nature of the cupule together with

its coverings by terms of spines, scales, bracts or bracteoles, lamellae etc., have been put forward

by the previous authors.

      Brett (1964), Abbe (1974), Macdonal (1979) and the others have given rational interpre-

tations but only to the cupule, and Fey & Endress (1981, 1983) have made further studies al-

though materials they used for the observation are only three species representing three dif-

ferent genera.  Their elaborate works on anatomical evidence from reproductive parts came at

a conclusion of critical importance which has reached a more reasonal interpretation than the

others before. “the cupular valves represent the outermost modified, sterile  branches  of  the

cymose partial inflorescence”, while Forman’s (1966)  interpretation of the  organ is “The

cupule can be regarded as wholly axial orgin”.  Furthermore, a similar but more detailed spe-

culation had been given previously by Trelease(1924): “the acorn cup is constituted by the

fused secondary branches of a dichasium”.

     The problem here turns to the views on the nature of their coverings around the outer wall

of the cupule, those various terms have been used for the coverings just given above.  Some

authors (Forman 1966, and the others) called them “emergences”, “appendages” collectively.

     Although Forman (1966 pp. 411-412) has pointed out some aspects of morphological and

anatomical resemblance between scales and leaves when he says “especially in Fagus orientalis

Lipsky, the appendages may in their nervation resemble small leaves”, he still doubt if “the

scales of Quercus and Lithocarpus have evolved from leaves”.  Fey & Endress (1981, p. 179,

abb. 95.3) gave only a figure and called it “blattartige schuppen”, but no description concer-

ning the phenomenon in the whole text.

      The second example was observed by the present authors. The cupule of Fagus engleriana

Seem. bears the lower rows of “bracts” much like the leaves from which they differ only in

diminitive form and size.  Not only do they possess a complex netted nerved system, but they

also contain chloroplast (greenish color even in dried status), which suggests that scales or

appendages be real leaves in origin.  The various forms of so called bracts or appendages just

given above, have been highly modified from leaves through a long history of evolution.

      This interpretation is also adoptable to all the other genera of the family Fagaceae.

      The modification of leaves, spines, tubercles, scales and even rings might be due to their

adaptation to new or changed environments.

Key words: Fagaceae, Fagus, Nothofagus