BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Marchantia polymorpha | Liverwort 



GENERAL BOTANICAL CHARACTERISTICS : 
Marchantia polymorpha has a flat, branching form.  The thallus is
generally 0.8 to 4 inches (2-10 cm) long and 0.3 to 0.8 inch (7-20 mm)
broad.  Thalli are dichotomously branched and exhibit apical growth.
Numerous rhizoids attach the gametophyte (thallus) to the soil.  Smooth
rhizoids penetrate the soil, while tuberculate rhizoids run horizontally
along the surface of the plant.  Marchantia polymorpha is dioecious
[5,8,9,34].
 


RAUNKIAER LIFE FORM : 
NO-ENTRY


REGENERATION PROCESSES : 
Marchantia polymorpha has two alternate forms in its life cycle:  a
gametophytic stage and a sporophytic stage.  The gametophyte propagates
itself vegetatively and also produces the gametes which give rise to the
sporophyte [8,9,55].

In sexual reproduction, antheridia and archegonia develop on separate
plant bodies and are borne on stalked antheridiophores and
archegoniophores, respectively.  Fertilization takes place prior to
elongation of the stalk, and a sporophyte is formed.  Spores with
hygroscopic elaters (slender threads that twist and coil as they dry and
propel spores into the air) subsequently develop and are released [8].
As many as 7 million spores may be formed on each plant [55].

Vegetative reproduction may occur as a result of fragmentation or gemma
cup production.  In fragmentation, new plants are formed when older
plant parts die at the fork of a branch of a thallus.  The two branches
then become separate individuals [8].  Gametophytes produce propagative
structures called gemma cups.  Each gemma gives rise to numerous gemmae
that are released when the cup fills with water.  Gemmae that are
transported to favorable sites form a pair of young plants [9,27].


SITE CHARACTERISTICS : 
Marchantia polymorpha grows on a wide variety of sites within its range
including cliffs, closed forests, alpine heathlands, peat bogs,
minerotropic fens, springs, swamps, grasslands, and tundra [2,5,8,50].
It is most often found on moist or wet mineral soil, especially in
recently burned areas [4,18,21].  Marchantia polymorpha grows best in
subcalcareous soil conditions (pH 6.0) under full sunlight [42,46].


SUCCESSIONAL STATUS : 
Obligate Initial Community Species

In central Canada, M. polymorpha is a primary invader of marshes and
edges of small ponds that are associated with fluctuating water tables
[12].

Marchantia polymorpha mats can interfere with the establishment of
seedlings of other vegetation [22].


SEASONAL DEVELOPMENT : 
Marchantia polymorpha gametophores appear and archegonia are ready for
fertilization in early to late May [18].  Sporogonia mature and spores
are released in July [18,34].  Gemmae production ceases in late spring
in Michigan [27].

Related categories for Species: Marchantia polymorpha | Liverwort