Characters of Leaf Epidermis in Hamamelidaceae (s. l.)-文献传递-植物通论文库

作者：Pan Kai-Yu, Lu An-Ming, Wen Jie

期刊：植物分类学报 1990年 1期

关键词：金缕梅科叶表皮气孔器；

Keywords:Hamamelidaceae, Leaf epidermis, Stomatal apparatuses,

Abstract:

Observed under LM in the present work were epidermal cells and stomatal

apparatuses of mature leaves in 37 species (50 samples) belonging to 19 genera and 6 sub-

families (Hamamelidaceae), of which 35 species (19 genera, 6 subfamilies) were also used for

observing under SEM cuticular membrane and wax sculpture, shape of stomata and stucture

of stomatal apparatuses of the lower epidermis.

(1) It is found that in the family cells of both upper and lower epidermis are tetragonal,

pentagonal and hexagonal or irregular; anticlinal walls are straight, arched, sinuolate and sin-

uate; stomatal apparatuses, which occur only on the lower surface, may be cyclocytic, stephano-

cytic, paracytic and anomocytic. All these characters of the leaf epidermis are of systematic

significance in the family (Fig. 1).

(2) Types of stomatal apparatuses are correlated to a certain extent with the pattern of

anticlinal walls of epidermal cells and other external morphological characters. In the majority

of cases, the groups, whose stomatal apparatuses are cyclocytic (Exbucklandioideae and Rhodo-

leioideae) and stephanocytic (Mytilaria Lec. and Tetrathyrium Benth.), all have straight or

arched anticlinal walls of lower and upper epidermal cells (except for Exbucklandia tonkin-

ensis with sinuate anticlinal walls of both upper and lower epidermal cells, and E. longipetala

with sinuate anticlinal walls of upper epidermal cells) (Plate 1:12, 13; 2:4), are all evergreen

trees or shrubs, and all have palmate veins and simple hairs (but Rhodoleioideae is pinnate-

veined or obscurely trinervious and has tufted hairs), indefinite floral parts and numerous ovu-

les, while the groups, whose stomatal apparatuses are paracytic (Disanthoideae, Chunia H.

T. Chang, Liquidambaroideae and Hamamelidoideae, which also has anomocytic type in small

portion of species) (Table 2), have sinuolate or sinuate anticlinal walls of upper and lower

epidermal cells (except for Chunia, Tetrathyrium, Corylopsis brevistyla and C. willmotiae,

which have straight and arched anticlinal walls), are mostly deciduous trees and shrubs, and

have pinnate veins and tufted hairs in most species, usually tetra-, or pentamerous flowers (ex-

cept for Liquidambaroideae, which has indefinite floral parts) and usually single ovule (but

Disanthoideae and Liquidambaroideae have numerous ovules).

(3) The subfamily Liquidambaroideae possesses polyporate pollen grains (Chang 1958,

1979), a circular vascular system in the midrib, at the centre of which is situated a secretory

channel (Huang 1982, 1986) and leaf teeth of the unique Altingioid tooth type (Li 1988) etc.

Based on these characters some authors tend to support the separation of the subfamily as a

family, Altingiaceae. The subfamily, however, shows strong differentiation of characters. For

example, in the subfamily, there are both evergreen and deciduous trees, palmate and pinnate

leaf veins, capitate, short-spicate and racemose inflorescences and half-interior and inferior ov-

aries. Furthermore, some characters in the subfamily, which are considered important for the

separation, are crisscross with those ih the other members of the Hamamelidaceae. Their sto-

matal apparatuses are similar to those in most groups of Hamamelidaceae (paracytic), and

Sycopsis sinensis also possesses polyporate pollen grains. The subfamily shares with the remain-

ing members of Hamamelidaceae many important characters, such as the presence of stipule,

two styles, 2-locular ovary, axial placenta, capsule. From the data available the separation of

the subfamily does not seem to be supported by adequate evidence, and it may well be a link

of the Hamamelidaceae with the related families.

(4) Considering the fact that the subfamily Disanthoideae and most members of the su-

bfamily Hamamelidoideae are of paracytic stomatal apparatuses and pentamerous flowers, the

present authors tend to agree with Huang‘s (1986) view that the subfamily Disanthoideae is

more closely related than the other subfamilies to Hamamelidoideae.

(5) Leaf epidermis of the family under study shows great diversity under SEM, even

within a genus in some cases, but it is generally stable at subfamily or genus level, and there-

fore SEM characters of the leaf epidermis is of certain taxonomic significance. For example,

Exbucklandioideae possesses ovate stomata. The cuticular membrane is annular around stomata

(Plate 3:3-6); most stomata are covered with lump-like cuticular membranes in Rhodoleio-

ideae (Plate 3:7,8,11,12); in Mytilaria the cuticular membrane appears lump-like, with a

minute-scaly waxy ornamentation (Plate 3:9); the cuticular membrane is striate, with large

scales on it in Chunia (Plate 3:10), and it is vermicular in Sycopsis (Plate 5: 9-11). Some

differences were also found among species in a genus, for instance, among the three species in

Corylopsis (Plate 4:12-14 and Table 2).

Characters of Leaf Epidermis in Hamamelidaceae (s. l.)

金缕梅科(广义)的叶表皮特征

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