Plant Structure, Growth, and Development Chapter 35 Plant Structure, Growth, and Development

Reproductive shoot (flower) Fig. 35-2 Reproductive shoot (flower) Apical bud Node Internode Apical bud Shoot system Vegetative shoot Blade Leaf Petiole Axillary bud Stem Figure 35.2 An overview of a flowering plant Taproot Lateral branch roots Root system

Fig. 35-3 Figure 35.3 Root hairs of a radish seedling

Prop roots “Strangling” aerial roots Storage roots Buttress roots Fig. 35-4 Prop roots “Strangling” aerial roots Storage roots Buttress roots Figure 35.4 Modified roots Pneumatophores

Rhizomes Bulbs Storage leaves Stem Stolons Stolon Tubers Fig. 35-5 Figure 35.5 Modified stems Tubers

Fig. 35-5d Figure 35.5 Modified stems Tubers

(a) Simple leaf Petiole Axillary bud Leaflet (b) Compound leaf Petiole Fig. 35-6 (a) Simple leaf Petiole Axillary bud Leaflet (b) Compound leaf Petiole Axillary bud Figure 35.6 Simple versus compound leaves (c) Doubly compound leaf Leaflet Petiole Axillary bud

Tendrils Spines Storage leaves Reproductive leaves Bracts Fig. 35-7 Figure 35.7 Modified leaves Bracts

Dermal tissue Ground tissue Vascular tissue Fig. 35-8 Figure 35.8 The three tissue systems Dermal tissue Ground tissue Vascular tissue

EXPERIMENT Very hairy pod (10 trichomes/ mm2) Slightly hairy pod Fig. 35-9 EXPERIMENT Very hairy pod (10 trichomes/ mm2) Slightly hairy pod (2 trichomes/ mm2) Bald pod (no trichomes) RESULTS Very hairy pod: 10% damage Slightly hairy pod: 25% damage Bald pod: 40% damage Figure 35.9 Do soybean pod trichomes deter herbivores?

Parenchyma cells in Elodea leaf, with chloroplasts (LM) 60 µm Fig. 35-10a Figure 35.10 Examples of differentiated plant cells Parenchyma cells in Elodea leaf, with chloroplasts (LM) 60 µm

Collenchyma cells (in Helianthus stem) (LM) Fig. 35-10b 5 µm Figure 35.10 Examples of differentiated plant cells Collenchyma cells (in Helianthus stem) (LM)

Sclereid cells in pear (LM) Fig. 35-10c 5 µm Sclereid cells in pear (LM) 25 µm Cell wall Figure 35.10 Examples of differentiated plant cells Fiber cells (cross section from ash tree) (LM)

Vessel Tracheids Pits Tracheids and vessels (colorized SEM) Fig. 35-10d Vessel Tracheids 100 µm Pits Tracheids and vessels (colorized SEM) Figure 35.10 Examples of differentiated plant cells Perforation plate Vessel element Vessel elements, with perforated end walls Tracheids

longitudinal view (LM) 3 µm Fig. 35-10e Sieve-tube elements: longitudinal view (LM) 3 µm Sieve plate Sieve-tube element (left) and companion cell: cross section (TEM) Companion cells Sieve-tube elements Plasmodesma Sieve plate Figure 35.10 Examples of differentiated plant cells 30 µm 10 µm Nucleus of companion cells Sieve-tube elements: longitudinal view Sieve plate with pores (SEM)

Primary growth in stems Fig. 35-11 Primary growth in stems Epidermis Cortex Shoot tip (shoot apical meristem and young leaves) Primary phloem Primary xylem Pith Lateral meristems: Vascular cambium Secondary growth in stems Cork cambium Axillary bud meristem Periderm Cork cambium Cortex Figure 35.11 An overview of primary and secondary growth Pith Primary phloem Primary xylem Root apical meristems Secondary phloem Secondary xylem Vascular cambium

Apical bud Bud scale Axillary buds This year’s growth (one year old) Fig. 35-12 Apical bud Bud scale Axillary buds This year’s growth (one year old) Leaf scar Bud scar Node One-year-old side branch formed from axillary bud near shoot tip Internode Last year’s growth (two years old) Leaf scar Figure 35.12 Three years’ growth in a winter twig Stem Bud scar left by apical bud scales of previous winters Growth of two years ago (three years old) Leaf scar

Cortex Vascular cylinder Epidermis Key to labels Zone of Fig. 35-13 Cortex Vascular cylinder Epidermis Key to labels Zone of differentiation Root hair Dermal Ground Vascular Zone of elongation Figure 35.13 Primary growth of a root Apical meristem Zone of cell division Root cap 100 µm

Figure 35.14 Organization of primary tissues in young roots Epidermis Cortex Endodermis Vascular cylinder Pericycle Core of parenchyma cells Xylem 100 µm Phloem (a) Root with xylem and phloem in the center (typical of eudicots) 100 µm (b) Root with parenchyma in the center (typical of monocots) Endodermis Key to labels Figure 35.14 Organization of primary tissues in young roots Pericycle Dermal Ground Vascular Xylem Phloem 50 µm

Root with xylem and phloem in the center (typical of eudicots) Fig. 35-14a1 Epidermis Key to labels Cortex Dermal Endodermis Ground Vascular Vascular cylinder Pericycle Figure 35.14 Organization of primary tissues in young roots Xylem 100 µm Phloem (a) Root with xylem and phloem in the center (typical of eudicots)

Root with xylem and phloem in the center (typical of eudicots) Fig. 35-14a2 (a) Root with xylem and phloem in the center (typical of eudicots) Endodermis Key to labels Pericycle Dermal Ground Vascular Xylem Phloem Figure 35.14 Organization of primary tissues in young roots 50 µm

Root with parenchyma in the center (typical of monocots) Fig. 35-14b Epidermis Cortex Endodermis Vascular cylinder Key to labels Pericycle Dermal Core of parenchyma cells Ground Vascular Figure 35.14 Organization of primary tissues in young roots Xylem Phloem 100 µm (b) Root with parenchyma in the center (typical of monocots)

Emerging lateral root Cortex Vascular cylinder 100 µm 1 Fig. 35-15-1 Figure 35.15 The formation of a lateral root 1 Vascular cylinder

Epidermis Emerging lateral Lateral root root Cortex Vascular cylinder Fig. 35-15-2 100 µm Epidermis Emerging lateral root Lateral root Cortex Figure 35.15 The formation of a lateral root 1 Vascular cylinder 2

Epidermis Emerging lateral Lateral root root Cortex Vascular cylinder Fig. 35-15-3 100 µm Epidermis Emerging lateral root Lateral root Cortex Figure 35.15 The formation of a lateral root 1 Vascular cylinder 2 3

Shoot apical meristem Leaf primordia Young leaf Developing vascular Fig. 35-16 Shoot apical meristem Leaf primordia Young leaf Developing vascular strand Figure 35.16 The shoot tip Axillary bud meristems 0.25 mm

Figure 35.17 Organization of primary tissues in young stems Phloem Xylem Sclerenchyma (fiber cells) Ground tissue Ground tissue connecting pith to cortex Pith Epidermis Key to labels Figure 35.17 Organization of primary tissues in young stems Epidermis Cortex Vascular bundles Dermal Vascular bundle Ground 1 mm Vascular 1 mm (a) Cross section of stem with vascular bundles forming a ring (typical of eudicots) (b) Cross section of stem with scattered vascular bundles (typical of monocots)

Fig. 35-18 Figure 35.18 Leaf anatomy Guard cells Key to labels Stomatal pore 50 µm Dermal Epidermal cell Ground Cuticle Sclerenchyma fibers Vascular Stoma (b) Surface view of a spiderwort (Tradescantia) leaf (LM) Upper epidermis Palisade mesophyll Bundle- sheath cell Spongy mesophyll Figure 35.18 Leaf anatomy Lower epidermis 100 µm Cuticle Xylem Phloem Vein Guard cells Vein Air spaces Guard cells (a) Cutaway drawing of leaf tissues (c) Cross section of a lilac (Syringa)) leaf (LM)

Figure 35.19 Primary and secondary growth of a stem in a two-year-old stem Epidermis Pith Cortex Primary xylem Primary phloem Vascular cambium Epidermis Primary phloem Cortex Vascular cambium Primary xylem Growth Vascular ray Pith Primary xylem Secondary xylem Vascular cambium Secondary phloem Primary phloem First cork cambium Cork Periderm (mainly cork cambia and cork) Growth Figure 35.19 Primary and secondary growth of a stem Secondary phloem Bark Vascular cambium Primary phloem Secondary xylem Late wood Cork cambium Early wood Periderm Secondary phloem Cork Secondary Xylem (two years of production) Vascular cambium 0.5 mm Secondary xylem Vascular cambium Secondary phloem Bark Primary xylem Most recent cork cambium Layers of periderm Vascular ray Growth ring Cork (b) Cross section of a three-year- old Tilia (linden) stem (LM) Pith 0.5 mm

Growth ring Vascular ray Heartwood Secondary xylem Sapwood Fig. 35-22 Growth ring Vascular ray Heartwood Secondary xylem Sapwood Fig 35.22 Anatomy of a tree trunk Vascular cambium Secondary phloem Bark Layers of periderm

Fig. 35-23 Figure 35.23 Is this tree living or dead?