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Home , Corymbia aparrerinja, Floral formula, Gynoecium, Oenothera biennis, Phylum

Angiosperms or Flowering Land : to Angiosperms the Magnoliophyta! The greatest adaptive radiation . . .

• is the largest radiation of plants • involves of dramatic adaptations to the problem of on land and being non- motile • exhibits successive rounds of speciation and subsequent extinction • sets the stage for the development of a land-based ecosystem with fungi and

Angiosperms - Flowering Plants! Fungi? ! • Fungi collectively are not a natural group Angiosperms focus of the course • More closely related to animals than to plants • comprise the phylum Magnoliophyta • vast majority of plant diversity

What are the non-angiosperm land plants? • DNA evidence has clarified much but not all of the relatioships of other phyla (= divisions)

See first pages of Chpts 1 & 3 for more detail (Plant )

1 Fungi? ! Fungi? ! Turning the Crown Upside Down: Gene Parsimony the Eukaryotic Tree of Life Traditional view of eukaryotic relationships

Katz et al. 2012 Fungi are here Green Plants are here Systematic

Charales - stoneworts! Extinct Land Plants - the first plants Ordovician Period (505 - 440 mya) • Green algal lineage • First evidence of land life at 460 mya • Closest relatives to land plants

Microfossils of with sporopollenin (degradation resistant material like lignin) and similar to modern day such as liverworts

Found worldwide in shales that were deposited at the marine-terrestrial interface

2 bryophytes! bryophytes! • earliest land plants - non vascular • dominant, 16000 • 3 lineages — they are not a natural group

mosses

Liverworts -

Mosses - Bryophyta

Hornworts - Anthoceratophyta liverworts liverworts

Extinct Land Plants - first vascular plants Lycopodiophyta - club mosses! Early Devonian Period (410 - 390 mya) • 3 families, 1150 species

Rhynia seen in the early Devonian (Rhynie • dominant, vascular, free sporing Chert ) is one of first vascular plants • they are sister to all other vascular plants 20 cm tall, no roots, no , primitive vascular - club mosses

Isoetes - quillworts Selaginella - spike mosses

3 Extinct Land Plants - the first Polypodiophyta - ferns! Late Devonian Period (390 - 360 mya) • 11000 species • immense variation in and habitat • spores produced in specialized sporangia • need a lot of systematic work - tropics! First true ferns [Protopteridium] - free sporing with complex sporangia & megaphylls

Polypodiophyta - ferns! Polypodiophyta - ferns! • includes the horsetails as unusual ferns! • includes the strange whish ferns! • 15 species in Equisetum • 6 species in 2 genera • vascular plants, reduced leaves, terminal • vascular plants, leafless green stemmed, sporangia lateral sporangia

Psilotum habit Psilotum branch Psilotum sporangia

4 Extinct Land Plants - the plants Extinct Land Plants – first

Late Devonian Period (390 - 360 mya) Permian Period (286 - 245 mya)

First “” - “seed ferns” [Archaeosperma]

Plants -like with dissected compound leaves, but produce naked seeds ( within • Big with net-veined protective coverings) leaves

• Seed bearing (derived from gametophyte) and forming (from male gametophyte)

Pinophyta - gymnosperms! Pinophyta - gymnosperms! • 870 species • 870 species • seed plants but seeds naked • seed plants but seeds naked • often divided into 4 phyla • often divided into 4 phyla • is one closer to angiosperms? • is one closer to angiosperms?

spruce juniper male female strobili

5 Pinophyta - gymnosperms! Pinophyta - gymnosperms! • 870 species • 870 species • seed plants but seeds naked • seed plants but seeds naked • often divided into 4 phyla • often divided into 4 phyla • is one closer to angiosperms? • is one closer to angiosperms?

gnetophytes

mature seeds

Gnetum

Ephedra male strobili mirabilis

Extinct Land Plants – first flowering plants Magnoliophyta - angiosperms! Cretaceous Period (146 - 65 mya)

Near the Jurassic/Cretaceous border, the first Angiosperms are seen

• 275,000 + species • seed plants with seeds encased in Triassic • flowers a “key innovation”

Archaefructus

6 Angiosperms - Flowering Plants! Angiosperms - Flowering Plants! • tremendous adaptive radiation on • tremendous adaptive radiation on land (and back into water) land (and back into water) • Eucalyptus regnans () over 100m tall and 19m dbh

Eucalyptus regnans (Myrtaceae) -Tasmania

Angiosperms - Flowering Plants! Angiosperms - Flowering Plants! • tremendous adaptive radiation on • tremendous adaptive radiation on land (and back into water) land (and back into water) • Wolffia microscopica • Rafflesia arnoldii (Rafflesiaceae) (Araceae) less than 1mm long from New Guinea, up to 1m across and 20lbs

0.1 mm

7 Angiosperms - Flowering Plants! Angiosperms - Flowering Plants! • tremendous adaptive radiation on • tremendous adaptive radiation on land (and back into water) land (and back into water) • largest inflorescence • largest numbers of flowers — titanum (Araceae) Corypha palm

Angiosperms - Flowering Plants! The — Why Important?!

The Flower: most significant feature of angiosperms

Magnoliophyta classification 1. unlike anything else in other plants & extremely variable & co-evolved with animals • previously divided into two 2. floral features used in describing and id’ing classes — dicots and monocots 3. plant specimens () must include flowers or derived features • artificial! 4. classification of angiosperms relies on flowers

• we will use Angiosperm Calochortus - fairy lanterns & mariposas (images: T. Givnish) Phylogeny Group (APG III) classification system of 2009

8 The Flower — What is it?! The Flower — What is it?! • “foliar theory” of flower - J.W. • specialized = stem + von Goethe in “Attempt to Interpret leaves (folia) the Metamorphosis of Plants” (1790) • shoot is highly modified and determinate (ceased to grow)

from Schleiden 1855

The Flower — What is it?! The Flower — What is it?! • developmental/evolutionary origin of the • thus, a flower is a specialized shoot that: flower still debated 1. is determinate (vs. indeterminate) 1. Euanthial theory - (foliar theory) - single shoot 2. has a modified stem with anthers compressed internodes 3. possesses modified leaves with 2. Pseudanthial theory - various functions, these determined compound shoot or cone by gene arrays (e.g., ABC model)

9 The Flower — What is it?! The Flower — What is it?!

The ‘ABC’ model of The ‘ABC’ model of floral part identity floral part identity The Plant , 2010

B A C

carpels

The Flower — What is it?! The Flower!

• thus, a flower is a specialized shoot that: read chpt 9 in Plant Systematics! • 1st half deals with 1. is determinate (vs. indeterminate) vegetative features - we will cover in lab 2 next week 2. has a modified stem with • 2nd half deals with flowers/ compressed internodes - lab 3 following week

3. possesses modified leaves with various functions, these determined by gene arrays (e.g., ABC model)

4. often clustered in an inflorescence (larger branch)

10 The Flower! The Flower!

1. : floral stalk, the stem 2. : modified floral stem or supporting the flower; sometimes axis from which arise the floral referred to as the appendages or modified leaves

The Flower! The Flower!

4. : the second of 3. : the outer whorl of leaves, leaves, typically brightly green and protective; collectively colored, attracting ; called the calyx collectively called the corolla

11 The Flower! The Flower!

5. : collective term for if both similar or if only 8. : the male structure of collectively, stamens are the sepals and petals one reduced set (sepals) flower comprising filament and androecium (= ‘house of anther males’)

The Flower! The Flower!

6. Filament: slender stalk of the stamen supporting 7. Anther: fertile portion of stamen that the anther; permits exsertion of anther with pollen dehisces to release pollen grains; composed of out of flower anther sacs

12 The Flower! The Flower!

Nuphar

Nectaries often near base of stamens - produce reward for visitors • stamens can be -like in primitive angiosperms! who will move pollen (‘pollinators’)

The Flower! The Flower!

13. Pistil: flask-shaped, female • all pistils (1 or more) are 13. Pistil: flask-shaped, female 12. : receptive portion structure comprising three referred to as the structure comprising three at top of style that receives main parts – often referred to (= ‘house of ’) main parts – often referred to and recognizes pollen as carpel(s) as carpel(s)

13 The Flower! The Flower!

13. Pistil: flask-shaped, female 11. Style: slender stalk of pistil 13. Pistil: flask-shaped, female 9. Ovary: basal portion of pistil structure comprising three above ovary that the pollen tubes structure comprising three that contains ovules; at maturity main parts – often referred to must pass through to reach eggs main parts – often referred to becomes with seeds as carpel(s) in ovules as carpel(s)

The Flower! The Flower!

Pollination biology Study of the pollen, its transfer, and movement down the style

13. Pistil: flask-shaped, female 10. Ovules: fertile portions of pistil structure comprising three that contain a female gametophyte main parts – often referred to (embryo sac); develop into seeds as carpel(s) after fertilization

14 The Flower! The Flower! Monocarpic

Pistil vs. carpel

How do you know?

3 examples

Carpels not fused 1. Monocarpic 1 floral ‘leaf’ in gynoecium Folded ‘leaf’ 1 carpel = 1 pistil 2. Apocarpic Carpels fused This gynoecium is monocarpic 3. Syncarpic (one carpel)

The Flower! The Flower! Apocarpic

• If 6 leaves separately carpels,

• then the flower has 6 carpels and 6 pistils,

• gynoecium is apocarpic (separate carpels)

1 carpel = 1 pistil

This gynoecium is palustris - Marsh marigold monocarpic (one carpel) 6 fruits (pistils) from 1 flower Gynoecium is apocarpic with 6 carpels or 6 pistils

15 The Flower! The Flower! Syncarpic Syncarpic

3 floral ‘leaves’ in 3 carpels = 1 pistil 3 carpels = 1 pistil gynoecium fuse 3 styles 1 style – 2 carpels passion fruit– 3 carpels starfruit – 5 carpels

This gynoecium is This gynoecium is • number of fused carpels is often clear in a cross of the fruit syncarpic syncarpic

The Flower! The Flower!

Placentation types - arrangement of ovules, types - arrangement of ovules, provides hints to the number of carpels provides hints to the number of carpels

Marginal - found in almost all monocarpic or apocarpic pistils

tomato – 2 carpels passion fruit– 3 carpels starfruit – 5 carpels Axile - found in some syncarpic pistils

• number of fused carpels is often clear in a cross section of the fruit = placenta tissue

16 The Flower! The Flower!

Placentation types - arrangement of ovules, Placentation types - arrangement of ovules, provides hints to the number of carpels provides hints to the number of carpels

Parietal - found in Free-central - found in some syncarpic a few syncarpic pistils pistils

The Flower! The Flower!

Placentation types - arrangement of ovules, Numerical plan - merosity, arrangement of perianth provides hints to the number of carpels • not necessarily stamens or carpels

Basal - found in some monocarpic, apocarpic, or syncarpic pistils

perianth spiralled perianth 5-merous Common in primitive Common in angiosperms

17 The Flower! The Flower!

Numerical plan - merosity, arrangement of perianth plan - perianth arrangement important in • not necessarily stamens or carpels biology

perianth 4-merous perianth 3-merous radially Flowers bilaterally symmetrical symmetrical Occasional in eudicots Common in monocots & some primitive angiosperms Flowers actinomorphic Flowers zygomorphic

The Flower! The Flower!

Connation: fusion of floral Adnation: fusion of floral parts from the same whorl parts from different whorls

• Simple adnation Stamens fused onto inner Fusion of carpels Syncarpic pistil surface of fused (connation) petals

• Complex adnation Sepals, petals, and stamens fuse to form a

Fusion of stamens Staminal tube Fusion of petals Corolla tube

18 The Flower! The Flower!

Adnation: fusion of floral Adnation: fusion of floral e.g., Drimys & sandwort parts from different whorls e.g., cherry & rose parts from different whorls No adnation! Connation (fusion of similar parts) may or may not occur Adnation of calyx, corolla, & stamens = hypanthium

The Flower! The Flower!

Adnation: fusion of floral Adnation: fusion of floral e.g., horse gentian & fuchsia parts from different whorls e.g., horse gentian & fuchsia parts from different whorls

19 The Flower! The Flower!

Floral formula - shorthand notation Adnation: fusion of floral e.g., horse gentian & fuchsia parts from different whorls

calyx, corolla, stamens 4 sepals (CAlyx) 4 petals (COrolla) ovary 8 stamens (Androecium) 4 carpels (Gynoecium) hypanthium

pedicel biennis Evening primrose

The Flower! The Flower!

Floral formula - shorthand notation Floral formula - shorthand notation

4 sepals (CAlyx) 4 sepals (CAlyx) 4 petals (COrolla) 4 petals (COrolla) 8 stamens (Androecium) 8 stamens (Androecium) 4 carpels (Gynoecium) 4 carpels (Gynoecium) • Carpels fused = 1 pistil Carpels fused = 1 pistil • Ovary inferior

Oenothera biennis Oenothera biennis Evening primrose Evening primrose Onagraceae Onagraceae

20 The Flower! The “flower” — what is it? Floral formula - shorthand notation • a flower is a specialized shoot that:

1. is determinate (vs. indeterminate) 4 sepals (CAlyx) 4 petals (COrolla) 8 stamens (Androecium) 2. has a modified stem with compressed internodes 4 carpels (Gynoecium) Carpels fused = 1 pistil 3. possesses modified leaves with various functions, these Ovary inferior determined by gene arrays (e.g., ABC model) • Hypanthium (+ hypanthium tube) Oenothera biennis 4. often clustered in an inflorescence (larger branch) Evening primrose Onagraceae

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