TY -JOUR
AU -Li-Hsia Chen
AU -Tseng-Chieng Huang
TI -Anatomical Study of Leaf and Stem of Formosan Pittosporum, as an Ecological Implication
PY -1986
DA -0000-00-00
JO -Taiwania
VL -31
IS -1
SP -41
EP -64
UR -https://taiwania.ntu.edu.tw/abstract/551
AB -Pittosporaceae is exculsively native to the Old World. There is only one genus, Pittoporum, with five species and a variety in Taiwan, They are found from lowland (P. tobira, P. pentandrum and P. moluccanum), through median (P. illicioides in part) to high altitudes (P. illicioides in part, P. illicioides var. angustifolium and P. daphniphylloides). Except for the cultivated P. pentandrum which will grow into small tree, most species of Formosan Pittosporum, including the wild P. pentandrum are small or large shrubs. They are all mesomorphic but more or less tend to be xeromorphic.
Carlquist (1977) introduced vulnerability and mesomorphy ratios to indicate the reflection of vessel elements under various ecological conditions. In Pittosporaceae as a whole, both the vulnerability ratios and mesomorphy ratio of Formosan Pittosporum are low. All alpine species, have low values of the ratio of palisade tissue to intercellular space; only P. daphniphylloides has a thick cuticle. Thus, the low figures of both ratios may reflect adaptation to a form of physiological drought, caused by the winter frost. For the lowland species, the thicker cuticle, the low figures for both ratios, may be an adaptation to the high tempratures, sunny weather and long period of drought in summer.
The study of anatomical characters of leaves and stems for Taiwan Pittosporum indicate that plants of the same species vary in anatomical characters when they grow in different environmental conditions, while different species, growing close together or under similar environments, have similar annatomical characters.
DO -10.6165/tai.1986.31.41