Glossary

Alternate

One leaf or bud per point on the twig, staggered up the stem.

Aril

A fleshy cup or coat around a seed, as on yew.

Axil

The angle between a leaf stalk and the twig, where a bud sits.

Bipinnate

Divided twice, so that each leaflet is itself made of smaller leaflets.

Bract

A modified leaf at the base of a flower or a cone scale.

Bud scale

A small protective leaf that covers a bud over winter.

Cambium

The thin growing layer under the bark that makes new wood and bark each year.

Catkin

A drooping spike of small flowers, as on birch, oak and willow.

Clone

A group of trees that are genetically identical, growing from one root system, as in aspen.

Compound leaf

A leaf divided into separate leaflets.

Conifer

A tree that bears its seeds in cones, usually with needles or scales.

Crown

The branches and leaves of a tree taken together.

Deciduous

Dropping all leaves at one season, usually autumn.

Dioecious

Having male and female flowers on different trees.

Double-toothed

A leaf edge where each tooth carries smaller teeth.

Drupe

A fleshy fruit around one hard stone, as in cherry.

Entire

A leaf edge with no teeth or lobes.

Evergreen

Keeping green leaves through the year.

Fascicle

A bundle of needles, as on pines.

Genus

The first part of a scientific name, shared by close relatives.

Lenticel

A small pore in bark that lets gas pass.

Lobe

A rounded or pointed part of a leaf separated by cuts.

Lopsided base

A leaf base where one side joins the stalk lower than the other, as in elm.

Monocot

A plant with a single seed leaf, such as a grass, lily or palm.

Node

The point on a twig where one or more leaves grow.

Opposite

Two leaves or buds at the same point, facing each other.

Palmate

Spreading from one point, like the fingers of a hand.

Pinnate

Arranged along a central stalk, like a feather.

Pith

The soft centre of a twig.

Pome

A fleshy fruit with a core, as in apple.

Samara

A seed with a papery wing.

Serrate

Having small sharp teeth along the edge.

Simple leaf

A leaf with a single undivided blade, or a lobed one.

Species

The second part of a scientific name, naming one kind of tree.

Spur

A short, knobby side shoot that carries tufts of needles or leaves.

Stomata

Tiny pores on leaves through which gas and water vapour pass.

Understorey

The smaller trees and shrubs growing beneath the main canopy.

Whorl

Three or more leaves at the same point on a twig.