Plant anatomy

Vegetative terminology

 

Major groups of plants

•Non-vascular (3 phyla)

–Mosses, liverworts (we won’t cover these)

•Vascular, non-seed bearing  (4 phyla)

–Ferns (also horsetails, clubmosses)

•Vascular, naked-seed  (4 phyla)

–Gymnosperms (we learn only conifers)

•Vascular, vessel-seed (1 phylum)

–Angiosperms = flowering plants = Phylum Magnoliophyta (most of our plants)

•Class Magnoliopsida = dicots

•Class Liliopsida = monocots

 

Dicots and Monocots

Dicots 

1. Seed with two cotyledons

2. Flower parts in fours or fives or multiples of these 

3. Leaf with netted veins 

4. Vascular cambium present (in older plants – can produce wood) 

 Monocots 

1. Seed with one cotyledon 

2. Flower parts in threes or multiples of three 

3. Leaf with parallel veins 

4. Vascular cambium absent (cannot produce wood, no trees in this group!)

Plant form (general terms)

•Annual – lives for one year (or season)

•Biennial – lives for two years

•Perennial – lives for more than two years

•Herb or herbaceous plant – having no persistent woody stem above ground

•Shrub – a woody plant, usually smaller than a tree with multiple stems

•Tree – a woody plant at least 20 feet tall at maturity, having a single stem at its base

•Vine – a woody or herbaceous plant that trails or climbs other plants or structures for support, no erect stem

Roots and stems

•Not all underground parts are roots

Shoot morphology

•Buds with bud scales protect apical meristem on woody plants

•Terminal (or apical) buds are found at branch tips

•Axillary (or lateral) buds are found at the base of all leaves

Shoot morphology

•Bud scales leave scars behind on twig when they fall off

•Terminal buds form once a year

•Scars along twig indicate age sometimes called annual scars

•Leaves leave leaf scars

 

Leaf terminology – the basic leaf

Simple vs. compound

•A simple leaf has an undivided blade

•A compound leaf has a blade divided into leaflets

•In woody plants look for buds - never at the base of a leaflet

•Herbaceous plants don’t need to make buds

•Terminal leaflets are usually present

Simple vs. compound

Phyllotaxy: Arrangement of leaves on a stem

Leaf venation

Leaf shape

Leaf margins

Leaf apices

Leaf bases