The " radicle " is the embryonic root of the plant, and grows downward in the soil ( the shoot emerges from the plumule ).
12.
The goose down plumules ( each cluster made up of thousands of tiny feathery fibers radiating from a central point ), are larger, loftier and stronger than duck down.
13.
Overall, the filaments most closely resemble the " plumules " or down-like feathers of some modern birds, with a thick central quill and long, thin barbs.
14.
The opening of the cotyledons exposes the shoot apical meristem and the " plumule " consisting of the first " true leaves " of the young plant.
15.
The larger individual plumules are what gives the greater loft . The only way to get down of this quality is by careful hand selection which is the major factor in its scarcity.
16.
Sixty days after germination the transfer of reserved from the seed has been completed, but it is only after 80 or 90 days that the young shoot ( the plumule ) emerges from the cotyledon.
17.
At each end of the axis is a growing point; one end ( the plumule ) is responsible for developing into the plant's shoot, the other end ( radicle ), its root.
18.
Gymnosperm seedlings also have cotyledons, and these are often variable in number ( multicotyledonous ), with from 2 to 24 cotyledons forming a whorl at the top of the hypocotyl ( the embryonic stem ) surrounding the plumule.
19.
The plumule is covered with a "'coleoptile "'that forms the first leaf while the radicle is covered with a "'coleorhiza "'that connects to the primary root and adventitious roots form from the sides.
20.
The seeds of corn are constructed with these structures; pericarp, scutellum ( single large cotyledon ) that absorbs nutrients from the endosperm, plumule, radicle, coleoptile and coleorhiza these last two structures are sheath-like and enclose the plumule and radicle, acting as a protective covering.
