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Endothecium In lens: Bulbous thickenings develop in the endothecial cells. In Magnolia stellata: reticulate thickenings. In Eucommia ulmoides: the endothecium is bilayered. 27
27 ● Endothecium In lens: Bulbous thickenings develop in the endothecial cells. In Magnolia stellata: reticulate thickenings. In Eucommia ulmoides: the endothecium is bilayered
Endothecium In Chelone glabra: the endothecial cells undergo periclinal divisions.And two to six layers are produced. Multilayered endothecium is a primitive feature,and there is a phylogenetic trend towards reduction of endothecial tissue. 28
28 ● Endothecium In Chelone glabra: the endothecial cells undergo periclinal divisions. And two to six layers are produced. Multilayered endothecium is a primitive feature, and there is a phylogenetic trend towards reduction of endothecial tissue
● Middle layers o Their number varies from none to two. ●Transient or ephemeral(暂时或短暂) Become compressed,crushed,or obliterated(压缩，粉碎，或涂掉)before the microsporangium is fully mature. 29
29 ● Middle layers ● Their number varies from none to two. ● Transient or ephemeral (暂时或短暂) ● Become compressed, crushed, or obliterated(压缩，粉碎，或涂掉) before the microsporangium is fully mature
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