In some cases, cataphylls perform a
transient function, after which they die and may shed. Those that shed early are said to be
caducous. The
sepals of
Papaver species are shed during the very opening of the
petals and are a dramatic example of caducous leaves. Cataphylls can have many other forms. Some, such as
spines,
corm-scales, and
bud-scales, may be
persistent but may not perform their major function until they die, whether or not they are physically shed. Examples of various kinds of living cataphylls include
bulb-scales,
rhizome-scales,
cotyledons, and scaly
bracts. though many kinds of cotyledons function as living tissue and remain alive until, at least, the end of their function, at which time they wither and may drop off. They begin as leaf
rudiments. Many kinds accumulate nutrient materials for storage, starting to give up their stored material as the plant germinates. Some, such as the
cotyledons of many
legumes,
conifers, and
cucurbits, develop chlorophyll and perform the first
photosynthesis for the germinating plant.
Corm scales Like bulb-scales,
corm scales are largely the basal parts of the photosynthetic leaves that show up above ground. Some species of
cormous plants, such as some
Lapeirousia, also produce cataphylls that act solely as tunic leaves for the corm. Unlike bulb-scales, however, the corm tunic has no significant storage function; that task is left to the
parenchyma of the
cortex of the corm. ==See also==