Agriculture Reference
In-Depth Information
December but only completely die as new leaves are produced. Summergreen
species produce their leaves in May and June and shed them in October; many
species, for example,
Athyrium brevifrons
and
Dryopteris phegopteris
, share this
habit with leaf longevity around a half-year. Wintergreen species such as
Scepteridium multifidum
var.
robustum
and
Polypodium japonicum
with a leaf
longevity of about 10 months produce new leaves in late July to early September
and shed their leaves in late May to early July.
Yoshida and Takasu (1993) reported similar observations of leaf longevity for
ferns in the warm temperate zone of central Japan. Summergreen species such as
Athyrium pycnosorum,
A. wardii,
Coniogromme japonica
var.
fauriei
, and
Cornopteris decurrenti-alata
had leaf longevities from 164 to 210 days. Among
evergreen species, the leaf longevities of
Polystichum retroso-paleoceum
,
Doryopteris polylepis
, and
D. lacera
were around 1 year. In a semievergreen spe-
cies such as
P. tripteron
only a few old leaves remained 300 days later when new
leaves emerged. True evergreen species such as
Microlepia marginata,
Rumohr
standishii,
Athyrium otophorum,
Blechnum niponicum
, and
Asplenium wrightii
had leaf longevities longer than 1 year and old leaves coexisting with newly pro-
duced leaves.
Asplenium wrightii
had the longest leaf longevity, more than 1,000
days (Yoshida and Takasu 1993).
Leaf Longevity of Gymnosperms
A branch of evergreen conifer (Abies firma)
