Bryophyte Morphology

bryophyte gametophyte

photoautotrophic

dominant

sexual stage

After meiospores released from capsule

form protonema

forms gametophore

forms gametangia

archegonia

female gametangia

antheridia

male gametangia

antheridia produce

biflagellate spermatozoid

sporophyte/zygote

2n

dependent on gametophyte

formed by foot, seta and capsule

Monoicous

both gametogania on one plant

Monoicous types

synoicous

paroicous

autoicous

parautoicous

synoicous

produce antheridia and archegonia interspersed in same cluster

paroicous

antheridia and archegonia in separate clusters in different leaf axils

autoicous

male and female organs in separate inflorescences

parautoicous

combination of paroicous synoicous

Dioicious

gametangia on separate plants

Dioicious types

heterodioicous

pseudoautoicous

heterodioicous

male plants smaller

pseudautoicous

dwarf male epiphytic on caulid or fyloids

Polyoicous

both monoicous and dioicous plants within one species

Dioicy is more common in

basal group

Percent dioicious liverworts

up to 90%

dwarf males are common in

some mosses

hornwort gametophyte spores (4)

remain in tetrads for long time

contact faces flattened

surface variously ornamented

mature gradually together with the capsule

hornwort gametophyte spore size

relatively large (25-80 micrometers)

hornwort gametophyte protonema (2)

very reduced (2-4 cells, filamentous)

no protonemal tubers (one spore produces one plant)

hornwort gametophore shape

always thalloid, rosette-like or strap shaped

hornwort gametophore size

1-3 (up to 5) cm

hornwort gametophore apical cell

wedge-shaped

hornwort gametophore thallus complexity

multi-layered, without internal differentiation

hornwort gametophore ventral side

mucilage cavities (contain Nostoc)

primitive pores

hornwort gametophore cells (3)

parenchymatic

no trigones

containing 1 (rarely 2) chloroplast with pyrenoid

parenchyma

Fundamental tissue composed of thin-walled living cells that function in photosynthesis and storage.

hornwort gametophore rhizoids

smooth, unicellular, unbranched rhizoids

hornwort gametophore ventral scales

none

hornwort gametophore mucilage

some cells produce

hornwort gametophyte asexual reproduction

rare

hornwort gametangia

formed dorsally in the central part of thallus

hornwort antheridia (3)

formed endogenously

embedded in cavities

at maturity spermatozoids break through the surface

hornwort antheridia maturation (2)

chloroplasts turn into chromoplasts

change from green to orange

chromoplasts

type of plastid that stores pigments that are responsible for the bright colors in fruit and flowers

hornwort spermatozoids

biflagellate

symmetric with right handed flagella

hornwort archegonia (3)

formed exogenously

later embedded in thallus

necks protrude above surface

hornwort paraphyses

present

hornwort monoicous or dioicious

monoicous with temporal differentiation of gametangia formation

hornwort sporophyte first division of zygote

longitudinal

hornwort sporophyte consists of

foot and long cylindrical capsule, no seta

hornwort haustorium

connects sporophyte and gametophyte

ripen gradually

hornwort growing sporophyte

enclosed in involucre, no calyptra

hornwort capsule elongation

by basal meristem

hornwort capsule size

0.5 - 12 cm

hornwort capsule wall (2)

multilayered with assimilatory tissue

functional stomata present

hornwort central sterile columella

surrounded by archesporial cells

Archesporial cell

spore forming tissue

hornwort archesporium produces

meiospores (n) and pseudoelators (2n)

hornwort capsule

splits into 2-4 valves

types of liverwort thalli

thalloid

semifolious

leafy

80% liverworts are in

leafy form

oil bodies

single-membrane bound organelles in the cells of liverworts that contain secondary metabolites like terpenoids

liverwort symbiosis (2)

symbiosis with cyanobacteria absent (except Blasiales)

most taxa associated with mycorrhizal fungi

liverwort gametophyte spores tetrads (2)

separate early

contact faces rounded

liverwort spore maturation (2)

mature simultaneously

released immediately

liverwort spore structure (2)

exine with varied ornamentation

taxonomically significant

liverwort number of spores per capsule

species specific

liverwort spores per capsule example

Marchantia polymorpha

up to 7,000,000

liverwort spore germination

exosporic or endosporic

epiphytic spore germination in liverworts

typically germinate inside spore

liverwort protonema (2)

reduced, never forming tubers

one protonema produces one plant

leafy liverwort gametophyte caulid

apical cell tetrahedral forming 3 merophytes

leafy liverwort gametophyte merophytes

2 lateral leaf rows