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Ch:21 Nonvascular Plants: Mosses, Liverworts, and Hornworts - Coggle…
Ch:21 Nonvascular Plants: Mosses, Liverworts, and Hornworts
No vascular tissues or seeds.
Sporophyte Generation of Mosses
mrgagametophytes are retained by gametophyte
zygote undergoes transverse division
develops foot which absorbs sugars, water and minerals.
apical sporangium called capsule
has true epidermis and stomata
seta is narrow stalk between foot and capsule
Mosses are homosporous.
For Ex: Mosses, Liverworts, hornworts
Characteristics of Nonvascular Plants
embryophytes with sporangia and gametangia
has cuticle and are terrestrial
Has alternation of generations
Classification of Nonvascular Plants
Division Bryophyta:Mosses
The Gametophyte Generation
ubiquitous, perennial and thrive in many places
Morphology
leafy stems grows together
leaves are part of gametophyte
gametophores grows from meristem
stems are slender
Water transport
hydroids conducts water and dissolves minerals
leptoids are present
mosses lacking hydroids conducts water by capillary action
Rhizoids helps anchoring stem.
Development
Protonema helps with growth
small chloroplast present
grow extensively producing many buds
Reproduction
gametophore produces gamentangia
mosses are oogamous
sperms produces at antheridia
eggs occur at archegonia
Bisexual species has both antheridia and archegonia in same gametophore.
Unisexual species have male and female gametophore
For Ex:
Funaria, Pottia
For Ex:
Barbula, Polytrichum
Metabolism And Ecology
Most of the mosses are tolerant of desiccation.
goes permanentely moist microhabitat
they thrive at low temperatures
can grow in hard surfaces
undergoes adaption for survival
Division Hepatophyta: Liverworts
undergoes alternation of generation
Sporophyte completely dependent on gametophyte
The Gametophyte Generation
Divided in two groups
Thallose liverworts
less resemblances to mosses
flat and ribbon like leaves
body without roots, stems and leaves=thallus
has rhizoids and air pores
Leafy liverworts
gametophyte resembles the moss
Thin leaves, sender stem
leaves are arranged in three rows, two being much larger
gametophore stem grows by apical cell.
stem tissues are simple parenchyma
The sporophyte generation
less variability in the sporophytes
morphology resemblances the mosses
#
has elaters that pushes spores out
no foot or seta formed
For Ex:
Riccia, Ricciocarpus
Division Anthocerophyta: Hornworts
small, inconspicuous thalloid plant
grows in moist soil hidden in grass
resembles thalloid liver worts
#
lacks oil body
has single large chloroplast in each cell
chloroplast has pyrenoid
The Gametophyte Generation
has 3/4 protonema cells
gametophores are ribbon like or heart like shaped
gametophyte is parenchymatous and succulent
internally, has many chambers
zygote divide longitudinally
gametangium develops dinstinctively
The Sporophyte Generation
has foot embedded in gametophore tissue
sporangium is long, hornlike cylinder
sterile cell layer is thick and has chlorophyll
has columella like mosses
#
basal meristem is active
lack of minerals, absence of growth factors and insufficient photosynthesis causes we
whether death.
For Ex:
Anthoceros, Phaeoceros
