81 Vascular Plant Diversity

f

80 CHAPTER 4 EVOLUTION AND DIVERSITY OF VASCULAR PLANTS UNIT II EVOLUTION AND DIVERSITY OF PLANTS 81

LYCOPODIOPHYTA Gleicheniales Polypodiales LYCOPODIOPSIDA Dipteridaceae (2/Il) Aspleniaceae (1—10/700+) Lycopodiaceae (5/300) Gleicheniaceae (6/125) Blechnaceae (9/200) ISOETOPSIDA Matoniaceae (2/4) Davalliaceae(4—5/65) Isoetaceae (1/200) Schizaeales Dennstaedtiaceae(11/170) Selaginellaceae (1/700) Anemiaceae (1/100+) Dryopteridaceae (40—45/1700) EUPHYLLOPHYTA Lygodiaceae (1/25) Lindsaeaceae (8/200) MONILOPHYTA Schizaeaceae (2/30) Lomariopsidaceae (4/70) EQifiSETOPSIDA Salviniales Oleandraceae (1/40) Equisetaceae (1/15) Marsileaceae (3/75) Onocleaceae (4/5) PSILOTOPSIDA Salviniaceae (2/16) Polypodiaceae (56/1200) Ophioglossaceae (4/55—80) Cyatheales Pteridaceae (50/950) Psilotaceae (2/17) Cibotiaceae (1/11) Saccolomataceae (1/12) MARATTIOPSIDA Culcitaceae (1/2) Tectariaceae (3—15/230) Marattiaceae (6/80) Cyatheaceae (4/600+) Thelypteridaceae (5—30/950) POLYPODIOPSIDA Dicksoniaceae (3/30) Woodsiaceae (15/700) Osmundales Loxomataceae (2/2) central vascular cylinder Osmundaceae (3/20) Metaxyaceae (1/2) SPERMATOPHYTA (See Chapter 5) Hymenophyllales Plagiogyriaceae (1/15) FIGURE 4.9 Anatomy of the root, an apomorphy of the vascular plants. A. Root whole mount. B. Root longitudinal-section. C. Whole Hymenophyllaceae (9/600) Thyrsopteridaceae (1/1) root cross-section. D. Close-up of central vascular cylinder, showing tissues. TABLE 4.1 Taxonomic groups of Tracheophyta, vascular plants (minus those of Spermatophyta, seed plants). Classes, orders, and family names after Smith et al. (2006). Higher groups (traditionally treated as phyla) after Cantino et al. (2007). Families in bold are described in found today in the Selaginellaceae of the lycophytes and all the pericycle or endodermis. Lateral roots penetrate the tis detail. Number of genera and species (often approximate), respectively, are indicated in parentheses, separated by slash mark. monilophytes (discussed later). In the Lycopodiaceae, sues of the cortex before exiting to the outside. Isoetaceae, and seed plants (see Chapter 5), the apical mer Numerous modifications of roots have evolved, most of istem is complex, consisting of a group of continuously divid these restricted to the flowering plants (see Chapter 9). Roots VASCULAR PLANT DIVERSITY spores, with a 3-branched laesura (Figure 4.1 lA); 2) monolete ing cells. of many, if not most, vascular plants have an interesting sym spores, with a laesura that is linear and unbranched (Figure Roots are characterized by several anatomical features. biotic interaction with various species of fungi; this associa A classification scheme of vascular plants, after Smith et al. 4.1lB); and 3) alete, lacking any evidence of a laesura. First, the apical meristem is covered on the outside by a tion between the two is known as mycorrhizae. The fungal (2006) and Cantino et al. (2007), is seen in Table 4.1. Of the rootcap (also called a calyptra; Figure 4.9A,B); stems lack component of mycorrhizae appears to aid the plant in both tremendous diversity of vascular plants that have arisen since RHYN IOPHYTES such a cell layer. The rootcap functions both to protect the increasing overall surface area for water and mineral absorp their first appearance some 400 million years ago, only the Rhyniophytes are a paraphyletic assemblage that included root apical meristem from mechanical damage as the root tion and increasing the efficiency of selective mineral absorp major lineages will be described here. These include the the first land plants with branched sporophytic axes, some of grows into the soil and to provide lubrication as the outer cells tion, such as of phosphorus. The fungus benefits in obtaining rhyniophytes, known only from fossils, plus clades that have which (but not all) also had vascular tissue. Rhyniophytes slough off. Second, with the exception of the Psilotopsida photosynthates (sugars and other nutrients) from the plant. modern-day descendants: the Lycopodiophyta (lycophytes) incLude the genus Rhynia (Figure 4.12A,B), a well-known (Psilotales and Ophioglossales), the epidermal cells away from and Euphyllophyta (euphyllophytes; Figure 4.1, Table 4.1). vascular plant from the early Devonian, ca. 416—369million the root tip develop hairlike extensions called root hairs See Bierhorst (1971) and Foster and Gifford (1974) for gen years ago. Rhyniophyte sporophytes consisted of dichoto (Figure 4.9A); these are absent from stems (although under eral information on vascular plant morphology. mously branching axes bearing terminal sporangia that ground stems of the Psilotales bear rhizoids, which resemble Features that have been used to classify vascular plants dehisced longitudinally. root hairs). Root hairs function to greatly increase the surface include sporophyte vegetative morphology (branching pat area available for water and mineral absorption. Third, roots tern, leaf type/shape/arrangement/venation, stem and leaf always have a central vascular cylinder (Figure 4.9C,D). As anatomy), life cycle and reproductive morphology (homo in stems, the mostly parenchymatous region between the vas spory/heterospory, sporophyll morphology, sporangium culature and epidermis is called the cortex (Figure 4.9C); the shape/dehiscence/attachment, spore morphology), and game center of the vascular cylinder, if vascular tissue is lacking, is tophyte morphology (whether green and photosynthetic or called a pith. Fourth, the vascular cylinder of roots is sur nongreen and saprophytic or mycorrhizal). Spore morphol rounded by an endodermis with Casparian strips (Figure ogy in particular has been useful in the classification of vas 4.9D). As with some stems, the endodermis in roots selec cular plant groups. (See Chapter 12.) Features include spore tively controls which chemicals are and are not absorbed by size, shape (e.g., reniform, tetrahedral, globose), sculpturing the plant, functioning in selective absorption. (An undifferen patterns, and whether green (photosynthetic)or not. One major tiated layer internal to the endodermis, called the pericycle, spore feature is related to the laesura (plural laesurae), the is also typically present.) Fifth, roots generally have endog differentially thickened wall region corresponding to the tetrad FIGURE 4.11 MONILOPHYTA. Spore morphology. A. Spore immature following triangularis, Pteridaceae). B. Spore enous lateral roots (Figure 4.10), in which new lateral roots FIGURE 4.10 Root cross-section (Liliumsp.), showing endoge attachment scar on each of the four spores withtriletescar (Penragramnw Aspleniaceae). originate by means of actively growing meristems, arising at nous lateral root, a charactenstic of vascular plant roots. meiosis. Three basic spore types are recognized: 1) trilete with monolete scar (Aspleniumnidus, vol. AL leaves)

an C. FIGURE

Lepidodendron, roots mately rhyniophytes. euphyllophytes mary diverged lycopods), The toxylem) prior meaning today were known bearing 82 (Figure (see (Figure sessed (Figure (Figure

LYCOPODIOPHYTA—LYCOPHYTES

extinct,

Stem

A Rhyniophytes

52(4):

later

Lycopodiophyta,

number

to woody

biomass

(Figure

bearing make

lateral

cross-section 300

4.7)

as

4.1).

4.1). or

4.1).

CHAPTER 4.12

shoot

woody,

that along was

831—902.]

discussion).

‘I

the within

are

million

up

in

trees

First,

terminal

“centrarch”

the

An

Zosterophyllophytes 4.13);

of sporangia,

The

of

much A—B.

which

zosterophyllophytes

the

system;

a

tree-sized

(see

Sigillaria,

stem

ancestrally extinct,

root

forests

apomorphies

lineage Rhynia

the

that

B.

the

immediate

years

stems

showing

Rhyniophytes.

no

of

sporangia.

4

Rhynia Within the later

lycophyte

axes

or

apical

roots

comprised

the B

lateral

C

these

during

probably lycophyte.

lycophytes

(positioned

similar

ago.

EVOLUTION

first-formed

of

of

Earth’s

discussion).

and

outer

of

stem

meristem

lacked

the

plants

rhyniophytes

Fossil

lineage

roots IReproduced

two

lycophytes

characterize

the

relatives

and

lycophytes,

to

wood.

A.

axes

a

paraphyletic,

Note

coal

had

large Carboniferous,

those

Reconstruction

features

[Zosterophyllophytina], that

both

remains (also euphyllophyte

at

develop,

xylem

embedded

leading

may

D. the

deposits.

lycophyll

no

Second,

AND

diverged

portion

(Figure

roots of Fossil

commonly

center).

are

from

leaves,

were

branch

the the (known

the

of

evolved

as to

dichopodial,

fossil

in these DIVERSITY Kidston,

impression and

now

scars.

lycophytes lycophytes lycophytes

they

of protostelic

lycophyte of

4.

“Rhynie”

after

but

into approxi

lineages

Rhynia

12C—E) the

as

a

extinct

group,

plants

called

do

later,

leaf-

pos

pro

two

pri

R.

the

in

of

and major,

chert.

lycophyll

OF

W.

phytes, refers phloem xylem roots protoxylem walls lycophytes, metaxylem (Selaginella FIGURE

C—E.

an

H.

VASCULAR

early,

Lang.

than

to

usually leaf

Lycophytes.

and

tissue.

the

the

exinct

4.13

showing

1921.

the

kraussiana),

that

the

first protoxylem

(i.e.,

(just

later

have

Third,

vascular

protoxylem

Transactions PLANTS LYCOPODIOPHYI’A.

tracheary are

C—D. toward

the

single

formed

(lycophyll)

typically an

the

reverse

plant.

apomorphic

leaf

Sigillaria,

(lycophyll) endarch

forms vein.

stems

the

cells

scars

forms metaxylem.

leaf

of

Note

E.

smaller of

the

stem

of

that

in

Fossil

‘cc

erect, the an

in Royal lycophytes

protoxylem. for

a

develop

extinct,

a

center), position

roots). the

Tip

position

and cast branched

Society

In

lycophytes.

of

of

have the

woody

within

In

dichopodial

have

Lepidodendron, relative

interior

exterior

roots

of

stem

the

Protoxylem

thinner

Edinburgh.

lycophyte.

an

a

stems

(without

patch

of

exarch

to

to

to

lyco

root

cell

the the the

of of

I

r

FIGURE metaxylem Fourth, are ventral, the Figure usually

all and that of by sporophytic photosynthesis.

plants ous

modified tion, discussion).

branched) distinctive (essentially the and

leaves,

meristem. from stem

leaves,

A

vascular The

mosses dosiventral

greatly

axis

are

are

ecological

developing

leaf

leaves

actively

plus

to

sporophytic

4.1

just

lycophytes,

lower,

the not

see develop

of

4.14

survive

(Figure

for

5E).

have

(i.e., increasing vein,

primary

(For plants.)

or Euphyllophyta.)

strictly associated

the

called in

synonymous

leaves

numerous

leaf-like

surface)

dividing

(i.e.,

A,B.

having

Fifth, adaptive

by This away

“leaves,” stem

from lacking

a

in

4.14C).

“leaves.”

an

more

leaves homologous

previously constituted

at Leaves

site

Lycopodium

flattened

paved

from vascular

or

intercalary

the

a least lycophytes

homologs

leaves.

and

cells

a

for

shoot

a

other

strategies, subtending

with

detailed

these

of area

gap

single,

the

Lycophylls,

the

photosynthesis. are dehisce

ancestrally,

(Although

lycophytes

very

and

cortex

tissue

stem “microphyll”).

apex.

in

inaccessible functions

way

available

Sporophytic

typically

a occur

stem

with

meristem,

have

the having

major

near have description

unbranched

center;

for

transversely enabling

cross-section

A

leaf vasculature

the

on

become

shoot the the

some

have like

are

sporophytic

adaptive

a

for

dorsiventral

gametophytes in

sporophytic

(see

dorsal,

Figure

evolution

stemlshoot i.e., habitats.

The called

plants

leaves light

all

Lycophylls sporangia liverworts

B some

is

evolutionarily of

Lycopodium,

at

(very

evolution

defined

showing

of

sporophytic

upper,

innovation

relative 4.14A,B).

shoots

the

capture lycophylls

(see

UNIT the

originate vascular

In

of

leaves,

organs base

leaves

rarely

apical

addi

stem,

only

vari

later that

and

and

as protoxylem

and

are

to

of

in

of

a II

phloem

EVOLUTION

suggests their lycophytes possibly

phytes ages the that

into

of and

plants. dation,

sterilization nonwoody, Crane, lies:

cussed LYCOPODIOPSIDA and

The family

are spory. in

moss the

protoxylem

Although

The the

(exarch)

that

having development

often solutes;

persistent,

the lack

Isoetaceae Lycopodiaceae

called

associated

Lycopodiopsida

enation

(e.g.,

and

is

only below.

Lycopodiaceae, from 1997.)

(Alternatively,

enation,

Some

originated

exarch

that

vascular

commonly

relatives),

and

one

herbaceous

Figure this

lycophytes all enations

enation

and

shoot

into

family

euphyllophytes

long-lived

AND

of

(to vascular

type

was

allowing

leaves

of

planation

the

periphery

tissue.

a

from

14.15A), of

vasculature

dorsiventral, called systems

associated to

which

of

members

Isoetopsida

the

DIVERSITY

(found,

lycophylls [Lycopodiales]

plants,

lycophyll,

described

that

spore,

evolved

the

plants

Lycopodiopsida,

phase

Lycophylls for

club-mosses,

are

of

survived

transformation

of

hut

more

evolved

stem). grouped

(see

e.g.,

external,

a

with

have

sporangia; tissue

may

being

they

condition independently.

in

planar

(Figure

may

may

later

efficient

detail

in

C. flattening

OF

to

in

shoots,

are

may

leading sporophytic.

independently

be

into Lycophyll

consist

fossil

have

the

fact discussion),

peg-like

and

posture.

PLANTS

true

4.1).

below. seen

and

have

present three see

of known

transfer

are resemble

fossil

evolved

vascular

zosterophyllo Selaginellaceae

small from

(“planation”)

in These

stem

solely

Kenrick

distinguished

evolved (no appendages structure. These

extant

Lycophylls

Such

some

vasculature

are

Sporangia evidence

as lycophyll

leaf

the

because append of

are

in

by

a homo

gap)

of plants,

a

water small,

plants

fossil

fami

stem

83

large

gra

the

and

dis via

the

the vol. AL leaves)

an C. FIGURE

Lepidodendron, roots mately rhyniophytes. euphyllophytes mary diverged lycopods), The toxylem) prior meaning today were known bearing 82 (Figure (see (Figure sessed (Figure (Figure

LYCOPODIOPHYTA—LYCOPHYTES

extinct,

Stem

A Rhyniophytes

52(4):

later

Lycopodiophyta,

number

to woody

biomass

(Figure

bearing make

lateral

cross-section 300

4.7)

as

4.1).

4.1). or

4.1).

CHAPTER 4.12

shoot

woody,

that along was

831—902.]

discussion).

‘I

the within

are

million

up

in

trees

First,

terminal

“centrarch”

the

An

Zosterophyllophytes 4.13);

of sporangia,

The

of

much A—B.

which

zosterophyllophytes

the

system;

a

tree-sized

(see

Sigillaria,

stem

ancestrally extinct,

root

forests

apomorphies

lineage Rhynia

the

that

B.

the

immediate

years

stems

showing

Rhyniophytes.

no

of

sporangia.

4

Rhynia Within the later

lycophyte

axes

or

apical

roots

comprised

the B

lateral

C

these

during

probably lycophyte.

lycophytes

(positioned

similar

ago.

EVOLUTION

first-formed

of

of

Earth’s

discussion).

and

outer

of

stem

meristem

lacked

the

plants

rhyniophytes

Fossil

lineage

roots IReproduced

two

lycophytes

characterize

the

relatives

and

lycophytes,

to

wood.

A.

axes

a

paraphyletic,

Note

coal

had

large Carboniferous,

those

Reconstruction

features

[Zosterophyllophytina], that

both

remains (also euphyllophyte

at

develop,

xylem

embedded

leading

may

D. the

deposits.

lycophyll

no

Second,

AND

diverged

portion

(Figure

roots of Fossil

commonly

center).

are

from

leaves,

were

branch

the the (known

the

of

evolved

as to

dichopodial,

fossil

in these DIVERSITY Kidston,

impression and

now

scars.

lycophytes lycophytes lycophytes

they

of protostelic

lycophyte of

4.

“Rhynie”

after

but

into approxi

lineages

Rhynia

12C—E) the

as

a

extinct

group,

plants

called

do

later,

leaf-

pos

pro

two

pri

R.

the

in

of

and major,

chert.

lycophyll

OF

W.

phytes, refers phloem xylem roots protoxylem walls lycophytes, metaxylem (Selaginella FIGURE

C—E.

an

H.

VASCULAR

early,

Lang.

than

to

usually leaf

Lycophytes.

and

tissue.

the

the

exinct

4.13

showing

1921.

the

kraussiana),

that

the

first protoxylem

(i.e.,

(just

later

have

Third,

vascular

protoxylem

Transactions PLANTS LYCOPODIOPHYI’A.

tracheary are

C—D. toward

the

single

formed

(lycophyll)

typically an

the

reverse

plant.

apomorphic

leaf

Sigillaria,

(lycophyll) endarch

forms vein.

stems

the

cells

scars

forms metaxylem.

leaf

of

Note

E.

smaller of

the

stem

of

that

in

Fossil

‘cc

erect, the an

in Royal lycophytes

protoxylem. for

a

develop

extinct,

a

center), position

roots). the

Tip

position

and cast branched

Society

In

lycophytes.

of

of

have the

woody

within

In

dichopodial

have

Lepidodendron, relative

interior

exterior

roots

of

stem

the

Protoxylem

thinner

Edinburgh.

lycophyte.

an

a

stems

(without

patch

of

exarch

to

to

to

lyco

root

cell

the the the

of of

I

r

FIGURE metaxylem Fourth, are ventral, the Figure usually

all and that of by sporophytic photosynthesis.

plants ous

modified tion, discussion).

branched) distinctive (essentially the and

leaves,

meristem. from stem

leaves,

A

vascular The

mosses dosiventral

greatly

axis

are

are

ecological

developing

leaf

leaves

actively

plus

to

sporophytic

4.1

just

lycophytes,

lower,

the not

see develop

of

4.14

survive

(Figure

for

5E).

have

(i.e., increasing vein,

primary

(For plants.)

or Euphyllophyta.)

strictly associated

the

called in

synonymous

leaves

numerous

leaf-like

surface)

dividing

(i.e.,

A,B.

having

Fifth, adaptive

by This away

“leaves,” stem

from lacking

a

in

4.14C).

“leaves.”

an

more

leaves homologous

previously constituted

at Leaves

site

Lycopodium

flattened

paved

from vascular

or

intercalary

the

a least lycophytes

homologs

leaves.

and

cells

a

for

shoot

a

other

strategies, subtending

with

detailed

these

of area

gap

single,

the

Lycophylls,

the

photosynthesis. are dehisce

ancestrally,

(Although

lycophytes

very

and

cortex

tissue

stem “microphyll”).

apex.

in

inaccessible functions

way

available

Sporophytic

typically

a occur

stem

with

meristem,

have

the having

major

near have description

unbranched

center;

for

transversely enabling

cross-section

A

leaf vasculature

the

on

become

shoot the the

some

have like

are

sporophytic

adaptive

a

for

dorsiventral

gametophytes in

sporophytic

(see

dorsal,

Figure

evolution

stemlshoot i.e., habitats.

The called

plants

leaves light

all

Lycophylls sporangia liverworts

B some

is

evolutionarily of

Lycopodium,

at

(very

evolution

defined

showing

of

sporophytic

upper,

innovation

relative 4.14A,B).

shoots

the

capture lycophylls

(see

UNIT the

originate vascular

In

of

leaves,

organs base

leaves

rarely

apical

addi

stem,

only

vari

later that

and

and

as protoxylem

and

are

to

of

in

of

a II

phloem

EVOLUTION

suggests their lycophytes possibly

phytes ages the that

into

of and

plants. dation,

sterilization nonwoody, Crane, lies:

cussed LYCOPODIOPSIDA and

The family

are spory. in

moss the

protoxylem

Although

The the

(exarch)

that

having development

often solutes;

persistent,

the lack

Isoetaceae Lycopodiaceae

called

associated

Lycopodiopsida

enation

(e.g.,

and

is

only below.

Lycopodiaceae, from 1997.)

(Alternatively,

enation,

Some

originated

exarch

that

vascular

commonly

relatives),

and

one

herbaceous

Figure this

lycophytes all enations

enation

and

shoot

into

family

euphyllophytes

long-lived

AND

of

(to vascular

type

was

allowing

leaves

of

planation

the

periphery

tissue.

a

from

14.15A), of

vasculature

dorsiventral, called systems

associated to

which

of

members

Isoetopsida

the

DIVERSITY

(found,

lycophylls [Lycopodiales]

plants,

lycophyll,

described

that

spore,

evolved

the

plants

Lycopodiopsida,

phase

Lycophylls for

club-mosses,

are

of

survived

transformation

of

hut

more

evolved

stem). grouped

(see

e.g.,

external,

a

with

have

sporangia; tissue

may

being

they

condition independently.

in

planar

(Figure

may

may

later

efficient

detail

in

C. flattening

OF

to

in

shoots,

are

may

leading sporophytic.

independently

be

into Lycophyll

consist

fossil

have

the

fact discussion),

peg-like

and

posture.

PLANTS

true

4.1).

below. seen

and

have

present three see

of known

transfer

are resemble

fossil

evolved

vascular

zosterophyllo Selaginellaceae

small from

(“planation”)

in These

stem

solely

Kenrick

distinguished

evolved (no appendages structure. These

extant

Lycophylls

Such

some

vasculature

are

Sporangia evidence

as lycophyll

leaf

the

because append of

are

in

by

a homo

gap)

of plants,

a

water small,

plants

fossil

fami

stem

83

large

gra

the

and

dis via

the

the 84

cones. ductive showing lycophyte

FIGURE

D.

organs.

CHAPTER

sporangia

Lycopodium

with

4.15

pendant

B.

LYCOPODIOPHYTA—LYCOPODIOPSIDA.

Lycopodium

having

4

annotinum,

branches

lateral

EVOLUTION

clavatum,

(F)

dehiscence,

strobilus

and

specialized

a

species

AND

close-up

adaxial

with

DIVERSITY

strobili

view

showing

strobili.

(left)

(G).

sporophylls.

and Lycopodiaceae.

C.

H.

OF

Huperzia

Phylloglossuni

abaxial

VASCULAR

E.

view

lucidula,

Lycopodium

A.

(right).

drummondii,

Huperzia

showing

PLANTS

F—G.

clavatum,

lucidula,

Lycopodium

sporangia

a

small,

sporophylls

a

species cormose

in

squarrosurn,

leaf

with

axils

lycophyte.

removed

unspecialized

with

a

large,

no from

specialized

epiphytic

strobilus

repro

of laterally termed family, indeterminate, podion, members, tive (Figure that formation.

a Lycopodiaceae—Club-Moss gia,

ca. dulous, endogenous, grow dichotomously vasculature branch are is The

some a “bulbils”) scale-like (eligulate). occurring sporophylls among trilete organized ranean distal

sporophyll

spp., and temperate Lycopodiella and includes family

Dried (used raw

terminal

single

The the

dominant,

The

300

pseudomonopodial,

is leaves

is

leaves

temperate

Phylloglossurn

from

experimentally species

mostly known Lycopodiaceae,

determinate,

margin as laesura. sporophylls spores

Lycopodiaceae

the

Lycopodiaceae vegetative

species. 4.15C)

and system

(relative has foot,

perennial

midrib

cultivated stuffing

the

to

This may aggregate

regions),

on and

in underground

sporophylls

Sporangia

are

(sometimes

photosynthetic

axis.

a

acicular,

the

are

specialized sporophylls

have from as worldwide),

terminal dichotomously

spp.;

worldwide

i.e., short

of

branched

Gametophytes

regions),

detach, are determinate and

simple,

in

(Figure

a

(lycophyllous/microphyllous),

to

other

photosynthetic,

material, the

leaves, strobilus

Spores

been

some

the

with

Huperzia resemblance

herbs. aggregated

(Figure

meaning ornamentals, Pseudolycopodiella

co-occur

stalks

of

(2

heteromorphic used

sporangium,

stem) like

appearing consist

are functioning are strobili;

used

sessile,

are 4.15) sporophylls

plectostelic); in

spp., continuous

rhizomes

portions

Lycopodiuin

short

species

or

differ

are distribution.

Lycopodiella

which The homosporous,

to

terrestrial

baskets, those

in

or

scale-like reproductive 4.15E).

or

similar

in

as

selago

that

treat globose with

Australia,

shoots family subterranean branched axils

cone

of

the

into a

are

in

spiral

roots

dehiscence

to lubricant

5 (e.g.,

of

local one of lateral,

it or size

resembling

axils

mycorrhizal,

genera:

Alzheimer’s), them transverse a

as

In nets), to a

used (Figure

growth. of

terminates the with all

corms,

in

(known

wolf’s

and

branch terminal in (ca.

or (Greek

or

vegetative

or are some

the

or

Economic

medicinal

leaves some

L.

of

lycophytes,

stem. (12

(ca.

some

whorled,

New epiphytic shoot,

(dichopodial),

as shape forming

on

generally

associated nonphotosynthetic,

tetrahedral, (in

dyes

40

specialized

complanaturn);

vegetative

adventitious

Huperzia

with

an

and 4.15B,D,G,H). occurs

spp.,

members

foot).

40

In

shoots

species, condoms, as

of

spp.,

lykos,

The

taxa

relative (sporophylls); Zealand).

emetic; and

shoot

and

from

consisting

“gemmae” other growth

ligule

a spp.,

saprophytic. either

a

propagules.

worldwide),

plants

dichotomy

fiber

importance protostelic

a

the

stems

tropical 5

the

dispersed reniform, and

along

mordants.

flattened

develop

that

wolf, sporan UNIT vegeta

general

(ca.

system

all

family

tropical

leaves leaves

of blades

absent with H. epiter

stems

rubber to

plants

after

pen

with

(e.g.,

and

and

the are

The

200 are

ser

the

the

of

or

in

+

&

a

II

dichotomously gloves) lights, for

2001) reniform rennial, nonphotosynthetic are gametophytes ISOETOPSIDA

The Isoetopsida from in (described

4.16, appendages within vegetative one for 4.17) microspores

specialized EVOLUTION

Megaspores (Figures (Figures and meagsporangium and

gitudinal-section ligule. FIGURE

•

The lLSj

photosynthetic

general being

microsporangia proposal

young,

two

those

are

for 4.18D,H,

including

Lycopodiaceae

refers

and, B.

lycophyllous

L -

the

and

phylogenetic 4.181,

Ligule, other

heterosporous,

produced

4.16

4.18,

in

information

of and

because

[Isoetales],

sporangia,

(Figures

on detail

developing

transversely

lycophytes

is

‘ to

mycorrhizal, the -.-

sporophyll

branched,

and

ligule

4.19D). 4.191,K) early

extant

AND

reproductive),

LYCOPODIOPHYTA—ISOETOPSIDA. that

the

close-up.

of

in

4.19).

the

Lycopodiopsida

below).

and

Sekiginella,

Selaginella

and

may they

herbs,

upper

in they megaspores,

A

flash

4.1

(

production

are ‘-:

studies

are microsporangia

resemble DIVERSITY

lycophyte and

The

fewer be are scale-like

Microspores 8E,

and

lycophylls.

dehiscing,

distinctive

act

erect,

(Figure

the

photography. Members

both

the

photosynthetic Wikstrom ;4

produced

(adaxial)

very

4.1

function

are

as

Selaginellaceae of

leaves strobilus more

numbers

near

9J,K)

prostrate,

of vegetative

glands, the

flammable,

produced

faniilies,

of

in

in

4.1).

which

in

which

family.

born of

in

eligulate

the

having OF

in

side

and

Isoetes). are two

of

Heterospory terminal

showing are being the

the See

and

providing

ligules

leaf

(typically PLANTS

on

much

Ligules Kennck

or

or

of

Isoetopsida

types leaves

in are

classified

same

relatively

øllgaard in

develop

megasporangia sporophylls

leaf

pendulous,

saprophytic.

homosporous,

and

large ,

the

Megasporangia base

fireworks

the

apomorphies

sporophyll

larger

strobili,

is

ligules

shoot

Isoetaceae of

or

leaf

sporangia

(2000a,b;

hydration not

are

numbers.

(Figures

four

ligule

that

(Figure

(1990)

spores,

A.

in

within

in

differ

clear;

(both

small

or

and that

tiny

pe and

85 Lon size

the

are

the

per 1

and

on 84

cones. ductive showing lycophyte

FIGURE

D.

organs.

CHAPTER

sporangia

Lycopodium

with

4.15

pendant

B.

LYCOPODIOPHYTA—LYCOPODIOPSIDA.

Lycopodium

having

4

annotinum,

branches

lateral

EVOLUTION

clavatum,

(F)

dehiscence,

strobilus

and

specialized

a

species

AND

close-up

adaxial

with

DIVERSITY

strobili

view

showing

strobili.

(left)

(G).

sporophylls.

and Lycopodiaceae.

C.

H.

OF

Huperzia

Phylloglossuni

abaxial

VASCULAR

E.

view

lucidula,

Lycopodium

A.

(right).

drummondii,

Huperzia

showing

PLANTS

F—G.

clavatum,

lucidula,

Lycopodium

sporangia

a

small,

sporophylls

a

species cormose

in

squarrosurn,

leaf

with

axils

lycophyte.

removed

unspecialized

with

a

large,

no from

specialized

epiphytic

strobilus

repro

of laterally termed family, indeterminate, podion, members, tive (Figure that formation.

a Lycopodiaceae—Club-Moss gia,

ca. dulous, endogenous, grow dichotomously vasculature branch are is The

some a “bulbils”) scale-like (eligulate). occurring sporophylls among trilete organized ranean distal

sporophyll

spp., and temperate Lycopodiella and includes family

Dried (used raw

terminal

single

The the

dominant,

The

300

pseudomonopodial,

is leaves

is

leaves

temperate

Phylloglossurn

from

experimentally species

mostly known Lycopodiaceae,

determinate,

margin as laesura. sporophylls spores

Lycopodiaceae

the

Lycopodiaceae vegetative

species. 4.15C)

and system

(relative has foot,

perennial

midrib

cultivated stuffing

the

to

This may aggregate

regions),

on and

in underground

sporophylls

Sporangia

are

(sometimes

photosynthetic

axis.

a

acicular,

the

are

specialized sporophylls

have from as worldwide),

terminal dichotomously

spp.;

worldwide

i.e., short

of

branched

Gametophytes

regions),

detach, are determinate and

simple,

in

(Figure

a

(lycophyllous/microphyllous),

to

other

photosynthetic,

material, the

leaves, strobilus

Spores

been

some

the

with

Huperzia resemblance

herbs. aggregated

(Figure

meaning ornamentals, Pseudolycopodiella

co-occur

stalks

of

(2

heteromorphic used

sporangium,

stem) like

appearing consist

are functioning are strobili;

used

sessile,

are 4.15) sporophylls

plectostelic); in

spp., continuous

rhizomes

portions

Lycopodiuin

short

species

or

differ

are distribution.

Lycopodiella

which The homosporous,

to

terrestrial

baskets, those

in

or

scale-like reproductive 4.15E).

or

similar

in

as

selago

that

treat globose with

Australia,

shoots family subterranean branched axils

cone

of

the

into a

are

in

spiral

roots

dehiscence

to lubricant

5 (e.g.,

of

local one of lateral,

it or size

resembling

axils

mycorrhizal,

genera:

Alzheimer’s), them transverse a

as

In nets), to a

used (Figure

growth. of

terminates the with all

corms,

in

(known

wolf’s

and

branch terminal in (ca.

or (Greek

or

vegetative

or are some

the

or

Economic

medicinal

leaves some

L.

of

lycophytes,

stem. (12

(ca.

some

whorled,

New epiphytic shoot,

(dichopodial),

as shape forming

on

generally

associated nonphotosynthetic,

tetrahedral, (in

dyes

40

specialized

complanaturn);

vegetative

adventitious

Huperzia

with

an

and 4.15B,D,G,H). occurs

spp.,

members

foot).

40

In

shoots

species, condoms, as

of

spp.,

lykos,

The

taxa

relative (sporophylls); Zealand).

emetic; and

shoot

and

from

consisting

“gemmae” other growth

ligule

a spp.,

saprophytic. either

a

propagules.

worldwide),

plants

dichotomy

fiber

importance protostelic

a

the

stems

tropical 5

the

dispersed reniform, and

along

mordants.

flattened

develop

that

wolf, sporan UNIT vegeta

general

(ca.

system

all

family

tropical

leaves leaves

of blades

absent with H. epiter

stems

rubber to

plants

after

pen

with

(e.g.,

and

and

the are

The

200 are

ser

the

the

of

or

in

+

&

a

II

dichotomously gloves) lights, for

2001) reniform rennial, nonphotosynthetic are gametophytes ISOETOPSIDA

The Isoetopsida from in (described

4.16, appendages within vegetative one for 4.17) microspores

specialized EVOLUTION

Megaspores (Figures (Figures and meagsporangium and

gitudinal-section ligule. FIGURE

•

The lLSj

photosynthetic

general being

microsporangia proposal

young,

two

those

are

for 4.18D,H,

including

Lycopodiaceae

refers

and, B.

lycophyllous

L -

the

and

phylogenetic 4.181,

Ligule, other

heterosporous,

produced

4.16

4.18,

in

information

of and

because

[Isoetales],

sporangia,

(Figures

on detail

developing

transversely

lycophytes

is

‘ to

mycorrhizal, the -.-

sporophyll

branched,

and

ligule

4.19D). 4.191,K) early

extant

AND

reproductive),

LYCOPODIOPHYTA—ISOETOPSIDA. that

the

close-up.

of

in

4.19).

the

Lycopodiopsida

below).

and

Sekiginella,

Selaginella

and

may they

herbs,

upper

in they megaspores,

A

flash

4.1

(

production

are ‘-:

studies

are microsporangia

resemble DIVERSITY

lycophyte and

The

fewer be are scale-like

Microspores 8E,

and

lycophylls.

dehiscing,

distinctive

act

erect,

(Figure

the

photography. Members

both

the

photosynthetic Wikstrom ;4

produced

(adaxial)

very

4.1

function

are

as

Selaginellaceae of

leaves strobilus more

numbers

near

9J,K)

prostrate,

of vegetative

glands, the

flammable,

produced

faniilies,

of

in

in

4.1).

which

in

which

family.

born of

in

eligulate

the

having OF

in

side

and

Isoetes). are two

of

Heterospory terminal

showing are being the

the See

and

providing

ligules

leaf

(typically PLANTS

on

much

Ligules Kennck

or

or

of

Isoetopsida

types leaves

in are

classified

same

relatively

øllgaard in

develop

megasporangia sporophylls

leaf

pendulous,

saprophytic.

homosporous,

and

large ,

the

Megasporangia base

fireworks

the

apomorphies

sporophyll

larger

strobili,

is

ligules

shoot

Isoetaceae of

or

leaf

sporangia

(2000a,b;

hydration not

are

numbers.

(Figures

four

ligule

that

(Figure

(1990)

spores,

A.

in

within

in

differ

clear;

(both

small

or

and that

tiny

pe and

85 Lon size

the

are

the

per 1

and

on heterosporous. Selaginella bear most the Heterospory manufacturing gametophytes (Figure gametophyte, Selaginella determinate with (Figure gametophyte, egg

(adaxial) different 86 Interestingly, — seed enlarged cell. specialized closely — mitosis, 4.12C—E) 4.1). Archegonium plants Egg CHAPTER (n) fertilization shoots. side FIGURE Each and Zygote and shoot mitosis, growth, related and Lepidodendron (2n) microsporangia develop which (see which of It organs Isoetes, the Isoetes sporophylls Some microspore and endospory belong (Figure the

mitosis, / growth, Chapter & Sperm 4.17 fossil to Embryo ——————————————— (n) differentiation contains 4 other produces entirely leaf (2n) Antheridium_jIS!I (Figure the Isoetes species are to growth, EVOLUTION 4. & Heterospory, tree megaspore base close 5). 19E). differentiation the possessed endosporic, also subtending or germinates within only Lepidodendron among 4.17). of “ligulate” only megasporangia & (Figure relatives In evolved GAMETOPHYTE differentiation Selaginella SPOROPHYTE archegonia, Isoetes, the antheridia, develops The a the leaf characteristic original the AND 4.18B,C). meaning to lycophytes, extant Female independently gametophytes were Male ligules Sporophyte the sporangia form have into and on housing DIVERSITY sporophylls woody, the spore lycophytes Gametophyte Gametophyte (2N) the (2n) (N) a relatives (n) and (n) strobili, that of a In female sperm- GENERATION upper being GENERATION the male wall. both on was Body via the the of Tsoetopsida in a OF mitosis, perennial Lepidodendron the species), meristem, from acicular, and Isoetaceae—Quillwort elongate. in the 5). (dichopodial). (Isoetes extant “unifacial,” VASCULAR reference The Wood blades development corm-like, (lsoetaceae growth, Microsporangium lower members Isoetaceae mitosis, [md. flat

with

© © herbs. The was becoming & basally producing (2n) grooves to mitosis, to Microsporocyte differentiation Stylites])Ica. growth, a The apparent and likely leaves

rarely 1/ terete Microspores and PLANTS of single The of consist Selaginellaceae) (2n) the growth, stems meiosis widened, Isoetes (n) a in & lobed roots an rhizomatous,

(generally 1 are only latter. vascular differentiation midrib family the evergreen Megasporangium apomorphy & are simple, of 200 cells are at differentiation stem — (Figure (usually) protostelic, the (Greek Megasporocyte sheathing, (lycophyllous), — Megaspores (2n) adventitious species. cambium in short,

and \ of base, duration spiral, one nieiosis with (2n) the 4.1) for isos, branch direction; aquatic but> lycophytes. the (Figure an the but in vertically-oriented apically ever, (but — of apical lobes and group a was 50 dichotomously some). — ligulate basal or one + 4.18) endogenous cm see etas, sometimes and lost terrestrial, including linear that in Chapter rosette, 1 lateral green, in genus at some was the the to D—I. nal-section sporangia, FIGURE Isoetes megasporangium 4.18 showing sp., reproductive. LYCOPODIOPHYTA—ISOETOPSIDA. trabeculae, containing D,E. ligule, Megasporangium velum, megaspores and numerous, visible. longitudinal-section C. UNIT Isoetaceae. smooth Isoetes microspores. II orcutii, A,B. with EVOLUTION Isoetes showing ligule howellii. and sporophylls spinose AND A. Plants megaspores. with DIVERSITY basal growing microsporangia F—I. in Microsporangium vernal OF PLANTS pool. or megasporangia. B. Close-up

longitudi 87 of heterosporous. Selaginella bear most the Heterospory manufacturing gametophytes (Figure gametophyte, Selaginella determinate with (Figure gametophyte, egg

(adaxial) different 86 Interestingly, — seed enlarged cell. specialized closely — mitosis, 4.12C—E) 4.1). Archegonium plants Egg CHAPTER (n) fertilization shoots. side FIGURE Each and Zygote and shoot mitosis, growth, related and Lepidodendron (2n) microsporangia develop which (see which of It organs Isoetes, the Isoetes sporophylls Some microspore and endospory belong (Figure the

mitosis, / growth, Chapter & Sperm 4.17 fossil to Embryo ——————————————— (n) differentiation contains 4 other produces entirely leaf (2n) Antheridium_jIS!I (Figure the Isoetes species are to growth, EVOLUTION 4. & Heterospory, tree megaspore base close 5). 19E). differentiation the possessed endosporic, also subtending or germinates within only Lepidodendron among 4.17). of “ligulate” only megasporangia & (Figure relatives In evolved GAMETOPHYTE differentiation Selaginella SPOROPHYTE archegonia, Isoetes, the antheridia, develops The a the leaf characteristic original the AND 4.18B,C). meaning to lycophytes, extant Female independently gametophytes were Male ligules Sporophyte the sporangia form have into and on housing DIVERSITY sporophylls woody, the spore lycophytes Gametophyte Gametophyte (2N) the (2n) (N) a relatives (n) and (n) strobili, that of a In female sperm- GENERATION upper being GENERATION the male wall. both on was Body via the the of Tsoetopsida in a OF mitosis, perennial Lepidodendron the species), meristem, from acicular, and Isoetaceae—Quillwort elongate. in the 5). (dichopodial). (Isoetes extant “unifacial,” VASCULAR reference The Wood blades development corm-like, (lsoetaceae growth, Microsporangium lower members Isoetaceae mitosis, [md. flat

with

© © herbs. The was becoming & basally producing (2n) grooves to mitosis, to Microsporocyte differentiation Stylites])Ica. growth, a The apparent and likely leaves

rarely 1/ terete Microspores and PLANTS of single The of consist Selaginellaceae) (2n) the growth, stems meiosis widened, Isoetes (n) a in & lobed roots an rhizomatous,

(generally 1 are only latter. vascular differentiation midrib family the evergreen Megasporangium apomorphy & are simple, of 200 cells are at differentiation stem — (Figure (usually) protostelic, the (Greek Megasporocyte sheathing, (lycophyllous), — Megaspores (2n) adventitious species. cambium in short,

and \ of base, duration spiral, one nieiosis with (2n) the 4.1) for isos, branch direction; aquatic but> lycophytes. the (Figure an the but in vertically-oriented apically ever, (but — of apical lobes and group a was 50 dichotomously some). — ligulate basal or one + 4.18) endogenous cm see etas, sometimes and lost terrestrial, including linear that in Chapter rosette, 1 lateral green, in genus at some was the the to D—I. nal-section sporangia, FIGURE Isoetes megasporangium 4.18 showing sp., reproductive. LYCOPODIOPHYTA—ISOETOPSIDA. trabeculae, containing D,E. ligule, Megasporangium velum, megaspores and numerous, visible. longitudinal-section C. UNIT Isoetaceae. smooth Isoetes microspores. II orcutii, A,B. with EVOLUTION Isoetes showing ligule howellii. and sporophylls spinose AND A. Plants megaspores. with DIVERSITY basal growing microsporangia F—I. in Microsporangium vernal OF PLANTS pool. or megasporangia. B. Close-up

longitudi 87 of