Glossary

A

auxin: plant hormone that regulates the amount, type, and direction of plant growth

B

basal: closest to the point of attachment

bud: a common term for meristem; the specialized growing region of a plant containing undifferentiated cells from which new cells and organs are developed

C

canopy: the cluster of leaves borne at the tip of the stem

chlorosis: a loss of chlorophyll resulting in white, yellow, or orange leaf color

chlorotic: see chlorosis

costapalmate: a leaf that is partially palmate and partially pinnate

crown: see canopy

crownshaft: a conspicuous cylinder formed by tubular leaf sheaths at the top of the stem

D

distal: farthest from the point of attachment

E

epinasty: increased growth of the upper surface of a plant part, such as a leaf, resulting in a downward bending of the part

L

lamina: the expanded portion of the leaf (blade)

leaf base: the basal portion of a leaf petiole that is attached to the stem

leaf blade: the broad, flattened distal portion of a leaf

leaf segment: divisions of palmate and costapalmate leaves

leaflet: divisions of pinnate leaves

M

meristem: the growing region of a plant, a special area of undifferentiated cells wherein new cells and organs are developed

midrib: see rachis

N

necrosis: dead tissue, usually desiccated and brown to gray in color

necrotic: see necrosis

P

palmate: hand-like

parenchyma: the fundamental, unspecialized tissue of plants, composed of thin-walled cells able to divide

petiole: leaf stem

pinnate: feather-like

R

rachis: the axis of a leaf beyond the petiole or an extension of the petiole into the leaf blade

S

spear leaf: the younges emerging leaf that has not yet opened