Kingdom Plantae

1
Kingdom Plantae

• Multicellular eukaryotic autotrophs
• Cell wall with cellulose
• Mostly terrestrial
• Alternation of generations

2
Organization of plant diversity

• Nonvascular plants
• Seedless vascular plants
• Seed plants
• Gymnosperms
• Angiosperms

3
Nonvascular plants

• No specialized water transport tissues
• No seeds
• Gametophyte is dominant generation
• Phylum Anthocerophyta
• Phylum Hepatophyta
• Phylum Bryophyta

4
Seedless vascular plants

• Vascular tissues
• Xylem specialized cells for transporting water
• Ploem specialized cells for transporting sugars
• Sporophyte generation dominant in life cycle
• Gametophyte independent of sporophyte
• Phylum Lycophyta (club mosses)
• Sporangia produced in strobilus
• Phylum Pterophyta (ferns allies)

5
Phylum Lycophyta (club mosses)

• Formed large forests in the late Paleozoic Era
  (300 mya)
• Formed coal deposits
• Living club mosses are all small plants
• E.g. "ground pine" "running cedar"
• Sporangia produced in strobilus (cone)
• Spores quite flammable (used as flashes in early
  photography)

6
Phylum Pterophyta

• Current classification in text includes
• Psilophytes (whisk ferns) and
• Sphenophytes (horsetails) in phylum Pterophyta
• Whisk ferns lack leaves, but have stems with
  stomata and photosynthetic tissue
• Horsetails like Equisetum have small leaves
  (microphylls) but most photosynthesis within stem
• Accumulate silica in stem (a.k.a. scouring rush)

7
Phylum Pterophyta (ferns)

• Very diverse with about 12,000 living species
• Some tree ferns up to 20m tall but most are small
• Most ferns grows with a specialized stem
  (rhizome)
• Rhizome grows horizontally and produces roots
  fronds (can grow for centuries)
• Fronds unfurl as fiddleheads
• Fronds produce sori
• A sorus has sporangia (release haploid spores)
• Spore grows into gametophyte

8
The seed plants

• Gymnosperms (naked seeds)
• Phylum Ginkgophyta
• Phylum Cycadophyta
• Phylum Coniferophyta
• Angiosperms (flowering plants)
• Phylum Anthophyta

9
The seed

• What is a seed?
• A sporophyte embryo within a protective coat
• What is its function?
• Reproduction
• Dispersal
• How does it compare to a spore?

10
Gymnosperms

• Produce pollen (usually wind-dispersed)
• Microgametophyte
• Ovules held on sporophyte plant
• Have true seeds
• Well suited to terrestrial habitats
• Dominated forests in Mesozoic era (with
  dinosaurs)
• Phylum Ginkgophyta
• Phylum Cycadophyta
• Phylum Coniferophyta

11
Phylum Ginkgophyta

• Has only one living species Ginkgo biloba
• Maidenhair tree
• Fan-shaped leaves
• Survives in wild in China
• Used extensively as an urban landscaping tree
• Very tolerant of pollution
• Dioecious
• Seeds covered with fleshy aril

12
Phylum Cycadophyta

• Abundant and diverse group in Mesozoic
• Only about 100 living species
• Mostly tropical
• Slow-growing, can be more than 1000 years old
• Leaves resemble palm those of palm trees
• Dioecious
• Large seed cones

13
Phylum Coniferophyta

• Approximately 700 species
• Major groups (families)
• Junipers
• Scale-like leaves
• Some with fleshy cones (aka juniper berries)
• Redwoods
• E.g. Sequoias, bald cypress, dawn redwood
• Some are deciduous

14
Phylum Coniferophyta

• Major groups (families)
• Yews
• Dioecious
• Seed in a fleshy cup-shaped aril
• Pine family
• Firs, hemlocks, spruces have needles borne
  singly (Christmas trees)
• Larches are deciduous
• Pines have needles in bundles

15
Angiosperms Phylum Anthophyta

• Became dominant terrestrial plants in Cenozoic
• More than 215,000 existing species described
• Modified leaves compose flowers
• Sepals, petals, stamens, carpels
• Flowers produce fruit that encapsulates seeds
• Double-fertilization produces polyploid endosperm

16
Monocots

• Seed with one cotyledon
• Flower parts in threes (or multiples)
• Leaves with parallel veins
• Vascular bundles interspersed in stem
• Examples
• Grasses
• Corn
• Bamboo
• Orchids

17
Dicots

• Seed with two cotyledon
• Flower parts in fours or fives (or multiples)
• Leaves with branching veins
• Vascular bundles arranged in circle in stem
• Examples
• Oaks
• Maples
• Geranium

18
Flowers

• Flowers are often highly modified
• Many are imperfect (having only male or female
  parts)
• Sepals may be modified to look like petals
• Some reduced and are wind-pollinated
• Some are showy in the UV spectrum to attract
  insects birds
• Some inflorescences that act as a single flower
• E.g. sunflowers