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Monocots Eudicots

Embryos

One cotyledon Two cotyledons

Leaf venation Veins Veins usually parallel usually netlike

Stems

Vascular scattered usually arranged in ring

Roots

Root system usually Taproot (main ) fibrous (no main root) usually present

Pollen grain with Pollen grain with one opening three openings

Flowers

Floral organs usually Floral organs usually in in multiples of three multiples of four or five

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Reproductive () Apical

Node Internode

Apical bud Shoot Vegetative shoot system Blade Stem Taproot

Lateral Root (branch) system

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Storage roots

Pneumatophores

“Strangling” aerial roots © 2014 Pearson Education, Inc. 4

Rhizome

Root

Rhizomes

Stolons

Tubers © 2014 Pearson Education, Inc. 5

Spines Tendrils

Storage Stem

Reproductive leaves Storage leaves © 2014 Pearson Education, Inc. 6 Dermal tissue Vascular tissue © 2014 Pearson Education, Inc. 7

Parenchyma cells with (in Elodea leaf) 60 µm (LM)

© 2014 Pearson Education, Inc. 8 Collenchyma cells (in stem) (LM) 5 µm

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5 µm

Sclereid cells (in pear) (LM)

25 µm

Cell wall

Fiber cells (cross section from ash ) (LM)

© 2014 Pearson Education, Inc. 10 Vessel Tracheids 100 µm

Pits Tracheids and vessels (colorized SEM) Perforation plate

Vessel element

Vessel elements, with perforated end walls Tracheids © 2014 Pearson Education, Inc. 11

Sieve-tube elements: 3 µm longitudinal view (LM)

Sieve plate Sieve-tube element (left) and companion cell: Companion cross section (TEM) cells Sieve-tube elements

Sieve plate 30 µm Nucleus of companion cell 15 µm Sieve-tube elements: longitudinal view Sieve plate with pores (LM) © 2014 Pearson Education, Inc. 12 Primary growth in stems Cortex Primary Shoot tip phloem (shoot apical and Primary young leaves) xylem Pith

Vascular cambium Lateral in stems Axillary bud Cork cambium meristem Periderm Pith Cortex

Primary phloem

Secondary Primary phloem Root apical xylem meristems Secondary Vascular xylem cambium

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Apical bud Bud scale Axillary

This year’s growth Leaf (one year old) scar Bud scar Node One-year-old branch formed Internode from axillary bud near shoot tip Last year’s growth (two years old) Leaf scar Stem Bud scar

Growth of two years ago Leaf scar (three years old)

© 2014 Pearson Education, Inc. 14 Cortical GLABRA-2 is expressed, cells and the cell remains hairless.

GLABRA-2 is not expressed, and the cell will develop a root hair. m µ 20

The root cap cells will be sloughed off before root hairs emerge.

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Cortex Vascular cylinder Dermal Ground Epidermis Vascular

Zone of Root hair differentiation

Zone of elongation

Zone of cell Mitotic division cells (including root apical meristem) 100 m Root cap µ

© 2014 Pearson Education, Inc. 16 Epidermis Cortex

Endodermis

Vascular cylinder Pericycle

Core of parenchyma cells

Xylem 100 µm (a) Root with xylem and phloem in Phloem 100 µm the center (typical of eudicots) (b) Root with parenchyma in the center (typical of monocots)

Endodermis Pericycle

Xylem

Phloem Dermal Ground Vascular 70 µm © 2014 Pearson Education, Inc. 17

Emerging Epidermis lateral 100 µm root Lateral root Cortex

Vascular Pericycle cylinder

© 2014 Pearson Education, Inc. 18 Shoot apical meristem Leaf primordia

Young leaf

Developing vascular strand

Axillary bud meristems

0.25 mm © 2014 Pearson Education, Inc. 19

Guard cells Stomatal

pore m Dermal µ Epidermal Ground 50 Cuticle Sclerenchyma cell Vascular fibers (b) Surface view of a spiderwort (Tradescantia) leaf (LM) Upper epidermis

Palisade mesophyll

Spongy mesophyll m

Lower µ epidermis Bundle- 100 sheath Cuticle cell Xylem Vein Phloem Guard Vein Air spaces Guard cells cells (a) Cutaway drawing of leaf tissues (c) Cross section of a lilac (Syringa) leaf (LM)

© 2014 Pearson Education, Inc. 20 Sclerenchyma Phloem Xylem (fiber cells) Ground tissue Ground connecting tissue pith to cortex

Pith Epidermis

Dermal Epidermis Cortex Ground Vascular Vascular bundles 1 mm 1 mm (a) Cross section of stem with vascular (b) Cross section of stem with scattered bundles forming a ring (typical of eudicots) vascular bundles (typical of monocots)

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(a) Primary and secondary growth Pith in a two-year-old woody stem Primary xylem Vascular cambium Primary phloem Epidermis Cortex Cortex Epidermis Primary phloem Vascular Vascular Growth Periderm cambium ray Primary Secondary Cork xylem Vascular phloem cambium cambium Cork Pith Bark Secondary Late Secondary xylem xylem Early wood Secondary phloem Cork First cork cambium

Periderm 1 mm (mainly Growth Vascular Growth cork ray ring cambia and cork) 1.4 mm (b) Cross section of a three-year- old Tilia (linden) stem (LM) Secondary phloem Most recent Layers of cork cambium periderm Secondary xylem Cork Bark

© 2014 Pearson Education, Inc. 22 Vascular cambium Growth Vascular cambium Secondary Secondary phloem xylem

After one year After two years of growth of growth

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Growth ring Vascular ray

Heartwood Secondary xylem Sapwood

Vascular cambium

Secondary phloem Bark Layers of periderm

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