Ceratophyllales and Basal Monocots

1
Ceratophyllales and Basal Monocots

• Plant Systematics (PBIO 309/509)
• Harvey Ballard

2
Ceratophyllales, Ceratophyllaceae, Hornwort family

• Submersed aquatic herb
• Stem w/single vascular strand, starch cells
• Leaves whorled, often dichotomously dissected
• Inflorescence a solitary flower
• Flowers unisexual (plants monoecious), radial
• Stamens 10-many
• Pollen inaperturate

Ceratophyllum
Judd et al. (2002)
3
Ceratophyllales, Ceratophyllaceae, Hornwort family

• Carpel 1
• Ovary superior, 1 per carpel
• Placentation apical
• Fruit an achene
• Stam. , 7-8, 10- 8, 0
• Carp. , 7- 8, 0, 1 achene

pistillate
staminate
Hugh Wilson website
4
Ceratophyllales, Ceratophyllaceae, Hornwort family

• Worldwide in freshwater habitats
• 1 genus (Ceratophyllum), 6 species in Ohio
• Habitat for fish, food for waterfowl, sometimes
  weedy
• Fossils to Early Cretaceous
• Equivocal placement sometimes basal to monocots
  or angiosperms

Ceratophyllum
Clayton (1998)
5
Global Distribution of Ceratophyllaceae
From Stevens (2006)
6
Monocots
Poaceae

• Mostly parallel-veined leaves (a few w/reticulate
  venation)
• Embryo with 1 cotyledon
• Stems w/scattered vascular bundles (also in
  Nymphaeaceae, some Piperaceae)
• Adventitious root system
• 3-merous flowers w/2 whorls (also in
  Nymphaeaceae)

Araceae
Liliaceae
Judd et al. (2002)
7
Monocots

• Pollen typically monosulcate
• All studies confirm monophyly of group, nested
  within paraphyletic dicots
• Organization followed
• Basal monocots
• Petaloid monocots
• Commelinoid monocots

Judd et al. (2002)
8
Basal Monocots
Acoraceae

• Two lineages basal to remaining monocots
• Acorales
• Alismatales
• Acoraceae formerly placed in Araceae
• Recent studies place it as sister to rest of the
  monocots removed to own order
• Alismatales above Acoraceae

Araceae
Potamogetonaceae
Judd et al. (2002)
9
Acorales, Acoraceae, Sweet Rush family

• Terrestrial herbs
• Ethereal oils present (?)
• Leaves 2-ranked, equitant
• Inflorescence indeterminate, a fleshy spike
  (spadix) subtended by bract (spathe) as extension
  of stem
• Flowers bisexual, radial, tiny
• Tepals 6

Acorus calamus
Judd et al. (2002)
10
Acorales, Acoraceae, Sweet Rush family

• Stamens 6
• Carpels 2-3, connate
• Ovary superior
• Placentation apical or axile
• Fruits tiny nuts on a spike

Acorus calamus
Judd et al. (2002)
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Acorales, Acoraceae, Sweet Rush family

• , 6, 6, 2-3 tiny nut
• N America, Eurasia southeast Asia, in wetlands
• 1 genus, 2-4 species Acorus calamus (Sweet Flag)
  in Ohio

Acorus calamus
Judd et al. (2002)
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Acorales, Acoraceae, Sweet Rush family

• Used medicinally, and previously to flag floors
  of churches
• Phylogenetically basal to rest of monocots

Acorus calamus
Judd et al. (2002)
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Global Distribution of Acoraceae
From Stevens (2006)
14
Alismatales

• 14 families, 3320 species
• Aquatic or wetland plants
• Major families covered
• Araceae
• Hydrocharitaceae
• Alismataceae
• Potamogetonaceae
• All studies support monophyly of order
• Two subordinal clades distinguished by flower
  characters

From Judd et al. (2002)
15
Alismatales, Araceae, Arum family

• Terrestrial, vining or epiphytic herbs, or
  aquatic herbs
• Calcium oxalate raphides present cyanogens,
  alkaloids and/or latex often present

Arisaema
From Judd et al. (2002)
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Alismatales, Araceae, Arum family

• Inflorescence indeterminate, dense fleshy spike
  (spadix) subtended by petaloid bract (spathe)
• Flowers bisexual, radial, tiny
• Tepals usually 4-6, sometimes absent

Lemna
From Judd et al. (2002)
17
Alismatales, Araceae, Arum family

• Stamens 1-6
• Carpels 1-3, connate
• Ovary superior
• Placentation axile or basal
• Fruits small berries, drupes, utricles or nuts on
  a spike

Amorphophallus
From Judd et al. (2002)
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Alismatales, Araceae, Arum family
staminate
carpellate

• , 4-6 or 0, 1-6, 1-3 berry, utricle, drupe,
  nut
• Worldwide, especially diverse in tropics and
  subtropics
• 109 genera, 2830 species major genera Anthurium,
  Philodendron, Arisaema (in Ohio) aquatics
  Peltandra, Symplocarpos and Wolffia (all in Ohio)

Arisaema
From Judd et al. (2002)
19
Alismatales, Araceae, Arum family

• Some used as root vegetables, incl. Alocasia,
  Colocasia (taro), Xanthosoma treatment required
  to remove calcium oxalate etc. many ornamentals
• Araceae monophyletic in all studies

Amorphophallus titanum
From Judd et al. (2002)
20
Alismatales, Araceae, Arum family

• Major clades
• Basal aroids (incl. Orontium, Symplocarpos)
• Aquatic duckweeds (formerly Lemnaceae) above
  basal aroids
• Core aroids
• Inflorescence generates heat to attract insects
  (mainly flies)
• Amorphophallus titanum is worlds largest
  inflorescence

Xanthosoma
Monstera
Lemna
Symplocarpos
From Judd et al. (2002)
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Global Distribution of Araceae
From Heywood (1993)
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Alismatales, Alismataceae, Water Plantain family
flowers

• Aquatic or wetland herbs
• White latex from laticifers
• Inflorescence determinate, scapose
• Flowers bisexual or unisexual (monoecious), radial

fruits
Sagittaria
From Judd et al. (2002)
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Alismatales, Alismataceae, Water Plantain family

• Sepals 3, distinct
• Petals 3, distinct
• Stamens usually 6-many
• Pollen usually 2- to polyporate
• Carpels (3-) 6-many, distinct
• Ovaries superior

fruits
Sagittaria
From Judd et al. (2002)
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Alismatales, Alismataceae, Water Plantain family
Sagittaria montevidensis

• Placentation basal
• Ovules 1-few per carpel
• Nectaries at base of whorls
• Fruit a cluster of achenes
• , 3, 3, 6-8, 6-8 achenes

From Judd et al. (2002)
25
Alismatales, Alismataceae, Water Plantain family

• Widespread in freshwater marshes, swamps, lakes
  and streams
• 16 genera, 100 species major genera Echinodorus,
  Sagittaria (both in Ohio)
• Rhizomes of Sagittaria eaten by rural folks, some
  ornamentals, achenes are food for waterfowl

Sagittaria lancifolia
From Judd et al. (2002)
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Global Distribution of Alismataceae
From Stevens (2006)
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Alismatales, Hydrocharitaceae, Frogs Bit or Tape
Grass family

• Aquatic herbs
• Inflorescence determinate, sometimes reduced to
  solitary flower
• Flowers bisexual or unisexual (monoecious or
  dioecious), usually radial

Staminate
From Judd et al. (2002)
28
Alismatales, Hydrocharitaceae, Frogs Bit or Tape
Grass family

• Sepals 3, distinct
• Petals 3, distinct
• Stamens 2-3-many
• Pollen grains usually inaperturate
• Carpels usually 3-6, connate
• Ovary inferior

Staminate
Limnobium spongia
Carpellate
From Judd et al. (2002)
29
Alismatales, Hydrocharitaceae, Frogs Bit or Tape
Grass family

• Placentation diffuse
• Nectar often from staminodes
• Fruit a berry or fleshy capsule
• Stam. , 3, 3, 2-m, 0
• Carp. , 3, 3, 0, 3-6 berry, fleshy capsule

Limnobium
From Judd et al. (2002)
30
Alismatales, Hydrocharitaceae, Frogs Bit or Tape
Grass family

• Widely distributed, especially in
  tropical/subtropical areas, fresh- or saltwater
• 17 genera, 100 species major genera Ottelia,
  Elodea and Vallisneria (last 2 in Ohio)
• Aquarium plants, weeds

Vallisneria and Hydrilla
From Judd et al. (2002)
31
Global Distribution of Hydrocharitaceae
From Stevens (2006)
32
Alismatales, Potamogetonaceae, Pondweed family

• Aquatic herbs
• Stem w/reduced vascular bundles often in a ring
• Leaves sometimes heteromorphic (floating
  submersed)
• Inflorescence indeterminate, spike

From Judd et al. (2002)
33
Alismatales, Potamogetonaceae, Pondweed family
fruits

• Flowers bisexual, radial
• Tepals lacking
• Stamens 4, w/fleshy basal appendages (perianth)
• Pollen inaperturate
• Carpels usually 4, distinct
• Ovaries superior

Potamogeton nodosus
flowers
From Judd et al. (2002)
34
Alismatales, Potamogetonaceae, Pondweed family
Potamogeton nodosus

• Placentation basal to apical
• Nectaries lacking
• Fruit a cluster of achenes or drupes
• , 0, 4 (appendaged), 4 achenes, drupes
• Worldwide in wetlands

flowers
fruits
From Judd et al. (2002)
35
Alismatales, Potamogetonaceae, Pondweed family

• 4 genera, 100 species major genera Potamogeton
  (in Ohio), Stuckenia
• Food for wildlife
• Ruppia formerly here, now segregated as its own
  family in Alismatales

Potamogeton americanus
From Judd et al. (2002)
36
Global Distribution of Potamogetonaceae
From Stevens (2006)
37
References

• Clayton, M. (ed.). 1998. Photo atlas of the
  vascular plants, 2nd ed. University of Wisconsin,
  Madison, WI.
• Heywood, V. H. 1993. Flowering plants of the
  world. Oxford University Press, New York, NY.
• Judd, W. S., C. S. Campbell, E. A. Kellogg, P. F.
  Stevens, and M. J. Donoghue. 2002. Plant
  systematicsA phylogenetic approach, 2nd ed.
  Sinauer Associates, Sunderland, MA. pp. 241-247.
• Stevens, P. F. 2006. Angiosperm phylogeny
  website. Version 6, May 2005. Accessed at
  http//www.mobot.org/MOBOT/research/APweb/.