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Home , Algae, Strobilus

Land Evolution: Land : Algae to Angiosperms Algae to Angiosperms The greatest adaptive radiation . . .

• is the largest radiation of • involves series of dramatic adaptations to the problem of life 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 Magnoliophyta • contains majority of plant diversity take 332 – spring 2019

What are the non-angiosperm land plants? • DNA evidence has clarified much but not all of the relationships of other phyla

See first pages of Chpts 1 & Chpts 3-4 for more detail (Plant Systematics, 2nd ed.)

1 Fungi? - stoneworts

• Green algal lineage take Botany 330 – fall 2019 Recent view of • Closest relatives to land plants eukaryotic relationships

• is in microbes with fungi/animals/plants forming a crown radiation

Fungi are here Green Plants are here

we are here

Charales - stoneworts Extinct Land Plants - the first plants

Ordovician Period (505 - 440 mya) take Botany 330 – fall 2019 • 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 Starry stonewort Nitellopsis obtusa L. Found worldwide in shales that were deposited at the marine-terrestrial interface Wisconsin’s latest (and greatest?) lake invasive

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

hornworts mosses mosses

Liverworts - Marchantiophyta

Mosses - Bryophyta

Hornworts - Anthoceratophyta liverworts liverworts

Extinct Land Plants - first vascular plants Lycopodiophyta - club mosses

Early Period (410 - 390 mya) • 3 families, 1150 species

Rhynia seen in the early Devonian (Rhynie • dominant, vascular, free sporing Chert fossil) is one of first vascular plants • they are sister to all other vascular plants 20 cm tall, no , 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 (or called “Monilophyta”) • immense variation in and • 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 whisk ferns! • 15 species in • 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 female 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?

pine spruce juniper male strobilus 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

ginkgo Gnetum

Ephedra male strobili Welwitschia mirabilis

Extinct Land Plants – first flowering plants Magnoliophyta - angiosperms

Cretaceous Period (146 - 65 mya)

Near the Jurassic/ border, the first Angiosperms are seen

• 275,000 + species (400,000 ?) • seed plants with seeds encased in Triassic • a “key innovation”

Archaefructus

6 Angiosperms - Flowering Plants Angiosperms - Flowering Plants • tremendous adaptive radiation on • tremendous adaptive radiation on land (and back into ) land (and back into water) • Eucalyptus regnans (Myrtaceae) 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 • Wolffia microscopica (Araceae) less than 1mm long (Araceae) less than 1mm long

0.1 mm

• Amorphophallus titanum (Araceae) over 2 m tall

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 • largest numbers of flowers — Amorphophallus titanum (Araceae) Corypha palm

Angiosperms - Flowering Plants Angiosperms - Flowering Plants • tremendous adaptive radiation on land (and back into water) • largest : Rafflesia arnoldii Magnoliophyta classification (Rafflesiaceae) from New Guinea, up to 1m across and 20lbs • previously divided into two classes — dicots and monocots

• artificial!

• we will use Angiosperm Phylogeny Group (APG III) classification system of 2009

8 Angiosperms or Flowering Plants The Flower — Why Important? the Phylum Magnoliophyta The Flower: most significant feature of angiosperms 1. unlike anything else in other plants & extremely Today & Monday: overview of the variable & co-evolved with animals and evolution of the flower – optionally read first 2. floral features used in describing and id’ing part of Chpt. 6 in Plant Systematics, 2nd ed. – 3. plant specimens () must include flowers or available at Canvas/Learn@UW derived features 4. classification of angiosperms relies on flowers Lab next two weeks: (1) vegetative features st & conifers – 1 half of Chpt 9 in Plant Calochortus - fairy lanterns & mariposas (images: T. Givnish) Systematics; (2) finish overview of flower and examine floral, , & inflorescence diversity – 2nd half of Chpt. 9

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

9 The Flower — What is it? The Flower — What is it? • developmental/evolutionary origin of the • developmental/evolutionary origin of the flower still debated flower still debated

1. Euanthial theory - (foliar theory) - single shoot, cone or strobilus anthers (male) ? (female)

2. Pseudanthial theory - compound shoot or cone, different “coalesce” or “condense” ? ?

The Flower — What is it? The Flower — What is it?

• thus, a flower is a specialized shoot that: The ‘ABC’ model of floral part identity 1. is determinate (vs. indeterminate) B 2. has a modified stem with compressed internodes A C

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

10 The Flower — What is it? The Flower — What is it?

The evolution of the ‘ABC’ • thus, a flower is a specialized shoot that: model of floral part identity The Plant , 2010 1. is determinate (vs. indeterminate)

2. has a modified stem with compressed internodes

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

4. often clustered in an inflorescence (larger branch)

The Flower The Flower

read chpt 9 in Plant Systematics! • 1st half deals with vegetative features - we will cover in lab 2 this week • 2nd half deals with flowers/ - lab 3 next week

1. : floral stalk, the stem supporting the flower; sometimes referred to as the

11 The Flower The Flower

2. : modified floral stem or 3. : the outer of leaves, axis from which arise the floral green and protective; collectively appendages or modified leaves called the calyx (CA)

The Flower The Flower

4. : the second whorl of leaves, 5. : collective term for if both similar or if only typically brightly colored, attracting sepals and petals (P) one reduced set (sepals) ; collectively called the corolla (CO)

12 The Flower The Flower

8. : the male structure of collectively, stamens are the 6. Filament: slender stalk of the stamen supporting flower comprising filament and androecium (= ‘house of the anther; permits exsertion of anther with pollen anther males’) (A) out of flower

The Flower The Flower

Nuphar

7. Anther: fertile portion of stamen that dehisces to release pollen grains; composed of anther sacs • stamens can be -like in primitive angiosperms!

13 The Flower The Flower

Nectaries often near base of stamens - 13. Pistil: flask-shaped, female • all pistils (1 or more) are produce reward for visitors structure comprising three main referred to as the ‘ ’ who will move pollen (‘pollinators’) parts – often referred to as carpel(s) (= house of females ) (G)

The Flower The Flower

13. Pistil: flask-shaped, female 12. : receptive portion 13. Pistil: flask-shaped, female 11. Style: slender stalk of pistil structure comprising three main at top of style that receives structure comprising three main above ovary that the pollen tubes parts – often referred to as carpel(s) and recognizes pollen parts – often referred to as carpel(s) must pass through to reach eggs in ovules

14 The Flower The Flower

13. Pistil: flask-shaped, female 9. Ovary: basal portion of pistil 13. Pistil: flask-shaped, female 10. Ovules: fertile portions of pistil structure comprising three main that contains ovules; at maturity structure comprising three main that contain a female gametophyte parts – often referred to as carpel(s) becomes fruit with seeds parts – often referred to as carpel(s) (embryo sac); develop into seeds after fertilization

The Flower The Flower

Study of the pollen, its transfer, and movement biology Pistil vs. carpel down the style How do you know?

3 examples

Carpels not fused 1. Monocarpic 2. Apocarpic Carpels fused 3. Syncarpic

15 The Flower The Flower When pistil = carpel When pistil = carpel 1. Monocarpic – when flower has only 1 pistil

legume flower 1 floral ‘leaf’ in gynoecium Folded ‘leaf’ 1 carpel = 1 pistil 1 carpel = 1 pistil

This gynoecium is monocarpic The pistil (vase-shaped structure) is made up of ONE carpel (one carpel)

The Flower The Flower When pistil = carpel When pistil = carpel 1. Monocarpic – when flower has only 1 pistil 2. Apocarpic – when flower has 2+ pistils

• e.g., 6 leaves (carpels) separately form pistils

• then the flower has 6 legume carpels and 6 pistils, flower legume 1 carpel = 1 pistil fruit This gynoecium is monocarpic (one carpel) 6 fruits (pistils) from 1 flower Gynoecium is apocarpic with 6 carpels and 6 pistils Caltha palustris - Marsh marigold

16 The Flower The Flower When pistil =/ carpel

3 floral ‘leaves’ in 3 carpels = 1 pistil 3 carpels = 1 pistil gynoecium fuse 3 styles 1 style tomato – 2 carpels passion fruit– 3 carpels starfruit – 5 carpels 3. Syncarpic – when 3. Syncarpic – when This gynoecium is This gynoecium is • number of fused carpels is often flower has only 1 pistil syncarpic syncarpic flower has only 1 pistil but 2+ carpels but 2+ carpels clear in a cross section of the fruit

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

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

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

17 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 eudicots angiosperms

18 The Flower The Flower

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

perianth 4-merous perianth 3-merous Flowers 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 asterids! Fusion of carpels Syncarpic pistil surface of fused (connation) petals legumes! • Complex adnation Sepals, petals, and stamens fuse to form a Fusion of stamens Staminal tube Fusion of petals Corolla tube

19 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., feverwort, honeysuckle, apple parts from different whorls e.g., feverwort, honeysuckle, apple parts from different whorls

20 The Flower The Flower

Floral formula - shorthand notation Adnation: fusion of floral e.g., feverwort, honeysuckle, apple parts from different whorls CA 4 CO 4 A 8 G 4 calyx, corolla, stamens 4 sepals (CAlyx) 4 petals (COrolla) ovary 8 stamens (Androecium) 4 carpels (Gynoecium) hypanthium

pedicel Oenothera biennis Evening primrose Onagraceae

The Flower The Flower

Floral formula - shorthand notation Floral formula - shorthand notation

— CA 4 CO 4 A 8 G 4 CA 4 CO 4 A 8 G 4

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

21 The Flower The “flower” — what is it? Floral formula - shorthand notation • a flower is a specialized shoot that: — CA 4 CO 4 A 8 G 4 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, Ovary inferior these determined by gene arrays (e.g., ABC model) • Hypanthium (+ hypanthium tube) 4. often clustered in an inflorescence (larger branch) Oenothera biennis Evening primrose Onagraceae

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