quaternary leaf vein [
PO:0008022; plant anatomy term ]
A leaf lamina vein (PO:0020138) arising from a tertiary leaf vein (PO:0008021).
More Synonyms: cross-vein, fourth order leaf vein, veinlet, vena cuaternaria (Spanish), 四次葉脈 (Japanese)
Comments: Vein orders only apply to hierarchically branching vein patterns, not to dichotomously branching vein patterns, as found in some ferns and gymnosperms.
quiescent center [
PO:0020149; plant anatomy term ]
A portion of meristem tissue (PO:0009013) that is part of a root apical meristem (PO:0020147) and consists of mitotically and metabolically inactive cells and is located behind the protoderm (PO:0006210) of the root (PO:0009005).
More Synonyms: centro de division de células del meristema (Spanish), 静止中心 (Japanese)
Comments: If a root cap is present, the quiescent center is behind the root cap.