Monocotyledons: monocots, Monocotyledoneae, or Liliopsida

Chapter 7Simpson, 2nd Edition

Monocots• 22% of all

angiosperms• 56,000 species

Diversity of Orders/Families1. Table 7.2 p. 2042. Table 7.3 p. 231

Class Liliopsida

According to Cronquist, 1988

Monocot Apomorphies

1. sieve tube plastids with cuneate proteinaceous inclusions

Monocot Apomorphies

2. atactostele stem vasculature• “random” v.b. scattered in stem• thus no vascular cambium & no true secondary growth

Monocot Apomorphies

Quick review:stele types Fig 10.16

ProtosteleSiphonostele Siphonostele

Dictyostele Eustele Atactostele

Monocot ApomorphiesQuick review:

secondary growth Fig 10.18

Monocot ApomorphiesQuick review:

secondary growth Fig 10.19

Monocot ApomorphiesQuick review:

secondary growth Figs 10.20-21

Monocot Apomorphies2. atactostele stem vasculature

• “random” v.b. scattered in stem• thus no vascular cambium & no true secondary growth

Monocot Apomorphies

3. parallel leaf venation (most spp)

Monocot Apomorphies

4. single cotyledon

Monocots

Characteristics1) derived from

primitive dicots2) by Lower

Cretaceous...• wide variety of

monocot leaves (100 mya)

3) monocots were the first significant dichotomy in the evolutionary diversification of the dicots

• sensu = in the sense of• s.s. = sensu stricto – strict sense• s.l. = sensu lato – broad sense

A. Order Alismatales• 13 families (2 covered)• well developed perianth• perianth biseriate, 3-parted

“The order has often been split into the Arales (containing only the Araceae) and the Alismatales, s.s. (largely equivalent to the Alismatidae, sensu Cronquist 1981, and Takhtajan 1997), but some recent molecular studies unite these two groups.”

sea-grasses: Hydrocharitaceae Thallasia

Araceae - Arum family104/3300 cosmopolitan; tropical and subtropical diversity

1) perennial herbs2) spathe - large bract or leaf subtending a

spadix; may be rolled into a tube with the spadix inside [as in Calla lilly]

3) spadix - a spike of small flowers on a fleshy axis; perfect or imperfect flowers

4) many spadix are monoecious with staminate flowers on the upper half and pistillate on the lower half

5) insect pollinated; some with strong odors (meat colored arum lilies - see video)

6) plant tissues with calcium oxalate - this can cause a mechanical injury to the mucosal linings

7) some worldwide economic importance8) number 1 houseplant family

A. Order AlismatalesP 2+2,3+3,(2+2),(3+3) or 0 A4,6,8 or (4,6,8) G(3) superior

Araceae - Arum familyA. Order Alismatales

Amorphophallus titanum – the largest inflorescence of any flowering plant

Lemna – duck weed

Wolffia – a floating aquatic in flower: P0 A1 G1 Worlds smallest flower

http://www.londongardenstrust.org

Araceae - Arum familyA. Order Alismatales

Philodendron

Dieffenbachia - dumbcane

Spathiphyllum - peace lilyColocasia esculenta - Elephant Ear or Taro

Araceae - Arum family

Zantedeschia - calla lilly

Colocasia - taro

Anthurium

A. Order Alismatales

Araceae - Arum family

Arisaema triphyllum - jack-in-the-pulpit

A. Order Alismatales

K3 C3 A6,9-∞ G3-∞ superior

Alismataceae - water plantain family15/88 aquatic & semiaquatic; temperate & tropic

1) aquatic herbs2) scapose3) apocarpous4) arrowhead shaped

leaves - in our species (Sagittaria)

5) fruit an achene6) fruit and

corm/rhizome important wildlife foodsource Alisma -

water plaintain

A. Order Alismatales

Alismataceae - water plantain family

A. Order Alismatales

Sagittaria arrow-leaf

B. Order Liliales

1) large monocot group2) 10 families, only 1

covered here3) much taxonomic

revision 4) Liliaceae s.l.

contained over 280 genera and 4000 species

B. Order LilialesLiliaceae - lily family16/600 cosmopolitan

1) perennial, terrestrial herbs (shrubs, woody vines)

2) bulbs, corms, rhizomes common3) petaloid perianth of tepals4) fruit a berry or capsule5) sheathing leaves, rarely

petiolate, simple6) past treatment as a large

polymorphic assemblage which is now broken into segregate families

P3+3 A3+3 G(3) superior

B. Order LilialesLiliaceae - lily family

Lilium

Tulipa Erythronium

Calochortus

B. Order Liliales Liliaceae - lily family

Erythronium albidum a spring ephemeral in our riparian woodlands

http://biology.clc.uc.edu/graphics/taxonomy/plants/

2010 Minnesota dwarf trout lily surveys at Nerstrand Big Woods State Park, Minnesota. Several volunteers participated in these surveys led by the Minnesota Department of Natural Resources.Nancy Sather (left) and Derek Anderson (right), Minnesota DNR, show a volunteer how to mark Minnesota dwarf trout lilies with flags to aid counts.Photo by USFWS; Tamara Smith

dalebenhamphotography

1. 14 families sensu APG III but Simpson recognizes 24 families

2. likely apomorphy is presence of black substance (phytomelan) in seed coat but not found in Orchidaceae

3. Many recent changes in family delineations

C. Order Asparagales

Agapanthus Yucca

Day-lily

IrisOrchid

Agapanthus Yucca

C. Order Asparagales

Yucca glauca – soapweed in Western NE

Agavaceae – agave family (=admired one)8/300 cosmopolitan/tropical diversity

1) perennial subshrubs, shrubs, trees, herbs

2) stems acaulescent caudex

3) leaves xeromorphic4) fruit a capsule5) xeric to mesic habitats6) often with CAM

photosynthesis7) indigenous sue for fiber,

food beverages, soap, medicinals

P3+3 A(6) G(3) superior or inferior, hypanthium in some

Yucca moth (Tegiticula) – symbiosis

C. Order Asparagales Agavaceae – agave family

Agave - Century plant

Agavaceae – agave family

C. Order Asparagales

C. Order Asparagales Agavaceae – agave family