|The leaf-like segments of Schlumbergera, are parts of the|
|Many brown algae produce large, leaf-like fronds.|
Line drawing from Allen & Gilbert, 1917, A textbook
|The "leaves" of leafy liverworts, like this Lejeunea, are|
flat extensions of the thallus.
|Club mosses, like this Lycopdiella cernua|
from Florida, have small scale-like leaves
|The fronds of ferns are|
upright shoots flattened into
a leaf-like configuration. From
Smith, 1955, Cryptogamic Botany.
|The large complex leaves of ferns are called megaphylls.|
lower surfaces, as well as conducting photosynthesis are upright shoots that became leaf-like
through fine-branching and flattening. Such leaves are called megaphylls. Megaphylls can be called leaves because they are produced sequentially at the tips of the ongoing rhizomes, have a definite size and shape, and fall off of the plant after one or a few seasons
|The upright shoots of horsetails are equivalent to the fronds of ferns,|
but consist of repeated whorls of small leaf-like branches and
elongate stem segments.
From Kerner & Oliver, 1904, The natural history of plants.
| This is an|
ancient horsetail ancestor called Lilpopia,
with small megaphylls, each equivalent
to just a small part of a fern frond.
|Cycads have compound leaves|
descended from the fronds of seed ferns.
|The leaves of the cycad Bowenia are doubly compound, and|
the most like ancient seed ferns.
|The leaves of conifers, such as this|
simple, and flat or needle-like.
|Angiosperm leaves, like this Tetrapanax,|
can be large and complex.
|Leaves in the eudicot family, Apiaceae, are typically|
compound, and can be quite fern-like, as in this variety of
|In the eudicot, Liquidambar, leaves|
develop their shape first in miniature,
then expand to their full size.
|The typical monocot leaf grows from the base,|
resulting in a strap-shaped structure and
From Rost, et al., Plant Biology