He describes the standard arrangement in angiosperms the nucellus joined by the chalaza to the integuments, which surround the nucellus except at the micropyle, through which the pollen tubes enter.
12.
He describes the standard arrangement in angiosperms the nucellus joined by the chalaza to the integuments, which surround the nucellus except at the micropyle, through which the pollen tubes enter.
13.
In " adventitious embryony " ( sporophytic apomixis ), an embryo is formed directly ( not from a gametophyte ) from nucellus or integument tissue ( see nucellar embryony ).
14.
Nutrients from the plant travel through the phloem of the vascular system to the funiculus and outer integument and from there apoplastically and symplastically through the chalaza to the nucellus inside the ovule.
15.
The seed megaspore was surrounded by two layers of tissue : a vascularised nucellus and a usually three-layered integument; the nucellus and integument were completely free except at the base of the ovule.
16.
The seed megaspore was surrounded by two layers of tissue : a vascularised nucellus and a usually three-layered integument; the nucellus and integument were completely free except at the base of the ovule.
17.
Kimoto et al . ( 2006 ) suggest " Cassytha " should be placed in the Cryptocaryeae tribe because it shares a glandular anther tapetum and an embryo sac protruding from the nucellus with other members of the Cryptocaryeae.
18.
The pollen enters a pollen chamber close to the nucellus, and there it may wait for a year before it germinates and forms a pollen tube that grows through the wall of the megasporangium ( = nucellus ) where fertilisation takes place.
19.
The pollen enters a pollen chamber close to the nucellus, and there it may wait for a year before it germinates and forms a pollen tube that grows through the wall of the megasporangium ( = nucellus ) where fertilisation takes place.
20.
In later, Pennsylvanian-age ovules such as " Lagenostoma " the nucellus became almost entirely encased by and fused to the integument, leaving just the small distal opening in the integument known as the micropyle through which pollen passed.
