The Monocots: Part 2 Commelinid Monocots - PowerPoint Presentation

Slide1

The Monocots: Part 2Commelinid Monocots

Spring

2014Slide2

Phylogeny of Monocot Groups

Acorales

Alismatales

AsparagalesLilialesDioscorealesPandanalesArecalesPoalesCommelinalesZingiberales

Basal

“Petaloid”

CommelinidSlide3

Fig. 7.17Slide4

Commelinid charactersSpecial type of epicuticular waxStarchy pollen

UV-fluorescent compounds in the cell walls

Starchy endosperm (except in the palms)

Lots of molecular supportSlide5

Fig. 7.45Slide6

Commelinid Monocot GroupsOrder Arecales – Palms

Arecaceae (Palmae)

Order Commelinales – Spiderworts, bloodworts, pickerel weeds

Order Zingiberales – Ginger, banana, and alliesOrder Poales – Bromeliads, Cat-tails, Rushes, Sedges, and Grasses Typhaceae* Juncaceae* Cyperaceae* Poaceae (Gramineae)*

*required familiesSlide7

Commelinoid Monocots:Arecales: Arecaeae (Palmae)

Widespread throughout tropical and warm temperate regions

“Trees” or “shrubs”, typically unbranched

Diversity: ca. 2,000 species in 190 generaFlowers: usually sessile, in compound-spicate inflorescences, these subtended by a bract (spathe); ovule 1 per locule Significant features: Leaves alternate or spiral, blades plicate, splitting in a pinnate or palmate mannerSpecial uses: coconut (Cocos nucifera), date (Phoenix dactylifera), rattan (Calamus), oils and waxes, ornamentalsFamily not requiredSlide8

Arecaceae –

Cocos nuciferaSlide9

Arecaceae

Economic plants and products:

Cocos nucifera

Coconut, oilSlide10

Arecaceae

Economic plants and products:

Phoenix dactylifera

DatesSlide11

Phylogeny of Monocot GroupsAcorales

Alismatales

Asparagales

LilialesDioscorealesPandanalesArecalesPoalesCommelinalesZingiberales

Basal

“Petaloid”

CommelinidSlide12

Commelinid Monocots: Zingiberales

Large herbs with vessels more or less limited to the roots

Silica cells present in the bundle sheaths

Leaves clearly differentiated into a petiole and bladeLeaf blade with penni-parallel venation, often tearing between the second-order veinsLeaf blade rolled into a tube in budPetiole with enlarged air canalsFlowers bilateral (or irregular)Pollen lacking an exineOvary inferiorSeeds arillate and with

perisperm (diploid nutritive tissue derived from the nucellus

)8 families and nearly 2000 species, mainly tropical

Not requiredSlide13

Fig. 7.55Slide14

ZingiberalesdiversitySlide15

Fig. 7.56Slide16

Phylogeny of Monocot GroupsAcorales

Alismatales

Asparagales

LilialesDioscorealesPandanalesArecalesPoalesCommelinalesZingiberales

Basal

“Petaloid”

CommelinidSlide17

Characters of PoalesSilica bodies (in silica cells) in the epidermis

Styles strongly branched

Loss of raphide (needle-like) crystals in most

Much molecular support for monophylyWind pollination has evolved several times independently within the orderEcologically extremely importantSlide18

Fig. 7.63Slide19

Commelinoid Monocots—Poales:Typhaceae

(The Cattail Family)

Widely distributed, especially in Northern Hemisphere

Emergent aquatic rhizomatous herbsDiversity: 8-13 species in 1 genusFlowers: small, unisexual; separated spatially on dense, compact spicate inflorescences; placentation apicalSignificant features: rhizomatous; long slender leaves; characteristic inflorescenceSpecial uses: ornamental aquaticsRequired taxa: TyphaSlide20

Sparganium

This genus is placed in

its own family, the

Sparganiaceae, in yourtext, but it is closelyrelated to Typhaceae andis included in Typhaceaein many treatments.

TyphaSlide21

Commelinid Monocots—Poales:Juncaceae

(The Rush Family)

Worldwide, mostly temperate regions; wet or damp habitats

Rhizomatous herbs, stems round and solidDiversity: 350 species in 6 generaFlowers: tepals 6, distinct; carpels 3 in superior ovary; stamens 6; fruit a loculicidal capsuleSignificant features: leaves 3-ranked, sheaths usually openSpecial uses: leaves used to weave rush baskets; some ornamentalsRequired taxa: JuncusSlide22

Juncaceae

Juncus

DistichiaSlide23

Juncaceae: Juncus

-important in many

wetland habitatsSlide24

Commelinid Monocots—Poales:Cyperaceae

(The Sedge Family)

Worldwide, usually in damp or semi-aquatic sites

Rhizomatous herbs, stems usually triangular in cross section and solidDiversity: 5,000 species in 104 generaFlowers: with 1 subtending bract; tepals absent or reduced to 3-6 scales or hairs; stamens 1-3; carpels 2-3 in superior ovary; fruit an achene (nutlet)Significant features: Inflorescence a complex group of spikelets; leaf sheaths closed, ligule lacking; silica bodies conicalSpecial uses: Papyrus used originally for paper; “water chestnuts” and a few other rhizomes edible, leaves used for weaving; some ornamentals.

Required taxa: CarexSlide25

Cyperaceae versus Juncaceae:Field Character

“Sedges have edges…

…and rushes roll.”Slide26

Fig. 7.65

Fig. 7.66DSlide27

Cyperaceae

Sedge spikelet

flower + subtending bract = floret

Flowers

:

Arranged in spikelets

Reduced

Wind-pollinated

Subtended by one bract

Reduced/absent perianth

flower

From Zomlefer 1994Slide28

Cyperaceae

Cyperus

Eleocharis Rhynchospora

(note bristle perianth)

Fruit type is the

achene

: very important in

the taxonomy of the family.Slide29

Cyperaceae

http://waynesword.palomar.edu/termfl3.htmSlide30

Cyperaceae: Carex

-presence of the perigynium (a sac-like

bract surrounding the female flower) in

addition to the subtending bract-leaves usually with a ligule-ecologically important, especially in wetlandsSlide31

Cyperaceae: CarexSlide32

Commelinid Monocots—Poales:Poaceae (Gramineae)

(The Grass Family)

Cosmopolitan

Primarily herbs, often rhizomatous; “trees” in most bamboos; stems are called culms, hollow or solidDiversity: >11,000 species in ca. 650 generaFlowers: small petals reduced to lodicules; each flower enclosed by two bracts (lemma and palea) = floret; stamens typically 3; carpels 3, but appearing as 2; fruit a caryopsisSignificant features: 1-many florets aggregated into spikelets, each with usually 2 empty bracts (glumes)

at the base; leaf with a liguleSpecial uses: many – grains, turf, fodder/forage, structural uses (e.g., bamboo).

Required familySlide33

Ecological

importanceSlide34

Economic

importance

Zea mays

Oryza sativa

Triticum aestivum

weeds

sugar cane

bambooSlide35

Poaceae: vegetative

structure

liguleSlide36

Poaceae: spikelet and flower structure

flower

Images from

Grasses of

Iowa

(mostly)Slide37

The fruit wall (pericarp) is completely fused to the seed coat.

Endosperm (3N; triploid) contains the bulk of starch storage in the seed.

The embryo is a pre-formed grass plant, with apical meristems (for both shoot and root) and protective organs (coleoptile and coleorhiza) which emerge first during germination. Anatomy of the Caryopsis (Grain)Slide38

Poaceae: caryopsis (grain)

Setaria

foxtail

Zea mays

corn or maizeSlide39

Origin of

grasses

ca. 70-80 mya

in southern-

hemisphere

forests

early grassesSlide40

Panicgrasses

*

(

Panicoideae

)

Rices

(Ehrhartoideae)

Bluegrasses

(Pooideae)

Bamboos

(Bambusoideae)

Puelioideae

Pharoideae

Anomochlooideae

Needlegrasses

*

(

Aristidoideae

)

Lovegrasses

*

(

Chloridoideae

)

Micrairoideae

*

Reeds

(Arundinoideae)

Oatgrasses

(Danthonioideae)

Major radiation

in Oligocene-

Miocene epochs

into open habitats

Origin of

grasses

ca. 70-80 mya

in forests

+

Stamens

reduced to 3Slide41

C

4

photosynthetic pathway

(in warm season grasses)

is advantageous under

higher temperatures, higherlight, and less

water when atmospheric CO

2 is < 500 ppmSlide42

Dispersal!Slide43

Poaceae: BamboosSlide44

Oryza

(rice)Slide45

Triticum

(wheat)Slide46

Zea

(maize or corn)Slide47

For more informationand images:

http://www.eeob.iastate.edu/research/iowagrasses/

The Grasses of Iowa Slide48

Grasses, Sedge, Rushes!

Stem

terete, hollow,

or solid, jointedLeaf ranks 2Leaf sheath Open, liguleInflor: SpikeletsPerianth: LodiculesFruit: Caryopsis

Triangular, solid, not obviously jointed

3

Closed

Spikelets

None or bristles/scales

Achene

Terete, solid,

not obviously

jointed

3

Open

Cymose

6 chaffy tepalsCapsuleSlide49

“Graminoids” - ComparisonSlide50

Next time: The “Basal” Eudicots…