PREFACE

Thank God we pray that the presence of GOD Almighty has bestowed grace and blessing me so that we can complete the task of this paper without a hitch. And do not forget we would like to thank Mr / Ms lecture who have guided us, so that we can complete the task of this paper. We realize in the preparation of this paper is far from perfect , for that we expect criticism and constructive suggestions for the perfection of this paper.

One thing we need to know that we are studying science is dynamic. Both the natural sciences and social sciences. In this paper we will discuss about the Taxonomy of Lower Plant , especially in discuss about byriophyta ant its taxonomy .

We hope that the topic of this paper can provide many benefits for us. There are explanation about the general charateristic , the morphology and life cycle.And dont forget also pray to god to give something back to those who support the preparation of this paper.

Sincerely

AuthorsTABLE OF CONTENTPREFACE ..............................................................................................................1TABLE OF CONTENTS.......................................................................................2

CHAPTER 1 : INTRODUCTION .......................................................................3CHAPTER 2 : DISCUSSION ..............................................................................42.1DIVISION BRYOPHYTA ...........................................................52.1.1. Class Musci.........................................................................102.1.1.1. Subclass Andreaeidae.........................................102.2DIVISION ANTHOROCEROTOPSIDA .................................142.2.1. Class Leiosporocerotopsida...............................................15

2.2.2. Class Athocerotopsida.......................................................152.3DIVISION HEPATICOPHYTA ................................................19

2.3.1. Class Marchantiopsida......................................................19

2.3.1.1 Sub class Marchantiidae......................................23

2.3.1.2 Sub class Sphaeocarpidae....................................26

2.3.2 Class Jungermanniopsida...................................................27

2.3.2.1 Subclass Metzgeriidae..........................................28

2.3.2.2 Subclass Jungermanniidae..................................31CHAPTER 3 : CONCLUSSION ........................................................................34REFERENCES ....................................................................................................35CHAPTER I INTRODUCTION

Bryophyta is the Plant Division that contains mosses. Plants in this Division have crude stems and leaves, but no roots. Instead of roots, they have "rhizoids." Rhizoids help anchor the plant to a surface, but they do not absorb nutrients like roots on other plants do. Instead of using flowers to make seeds, mosses release spores from their leaves. Spores can travel by water and make new mosses in new locations. Water is very important to mosses, so they can grow and spread; however, mosses can survive even when they dry out. When they become wet again, they revive and continue growing. (S.M. Reddy : 1996 )After flowering plants and ferns, mosses are the most diverse group of plants, with more than 10,000 species in 700 genera. This makes mosses almost twice as diverse as mammals. Mosses don't receive as much attention from us as flowering plants, ferns, or conifers because most mosses are small and inconspicuous.They have no vascular tissue or wood to lend them structural support, nor do they have large leaves or showy cones or flowers. This does not mean that mosses are not important; in fact, mosses play important roles in reducing erosion along streams, water and nutrient cycling in tropical forests, and insulating the arctic permafrost. (www.ucmp)CHAPTER IIDISCUSSION

TAXONOMY OF BRYOPHYTA

2.1. DIVISION BRYOPHYTA (MOSSES)Although the bryophyte is used as a collective term for all of these -Bryophyta(mosses), Hepatophyta (liverworts), and Anthoceratophyta (hornworts). Characteristics of Mosses , Mosses are mostly-terrestrial bryophytes.Mosses are found in a range of habitats, although moist and shady habitats are more common. Mosses are often epiphytes. The dominant phase of the moss life cycle is the gametophyte (haploid). The plant is called a thallus, they may be erect or prostrate (axis along the ground). Mosses have radial symmetry, in that a cut down the long axis of an individual gives two similar halves. The gametophyte has a stem like axis with spirally arranged leaves, which are known as phyllids . Mosses attach to their substrate with multicellular rhizoids .Moss leaves are variable in shape.Leaves usually consist of a single cell layer and are traversed by a midrib that is always more than one cell in thickness. It lacks xylem and phloem.The plant body may have conducting tissue. The xylem-like conducting tissue is called hydroid. The phloem-like conducting tissue is called leptoid. All mosses have a sporic (diplohaplontic) life cycle that is oogamous.

Table 2.1.1. Distinguishing Characters of Division Bryophyta , Division ( Hepatophytaand Division Anthocerotophyta)Character Bryophyta Marchantiophyta Anthocerotophyta

Protonema Filamentous, forming many buds Globose, forming one bud Globose, forming one bud

Gametophyte form Leafy shoot Leafy shoot or thallus; thallus simple or with air chambers Simple thallus

Leaf arrangement Leaves in spirals Leaves in three rows Not Applicable

Leaf form Leaves undivided, midvein present.Leaves divided into 2+ lobes, no midvein Not Applicable.

Special organelles None Oil bodies Single plastids with pyrenoids.

Water conducting cells Present in both gametophytes and sporophytes Present only in a few simple thalloid forms Absent.

Rhizoids Brown, multicellular Hyaline, one-celled.Hyaline, one-celled

Gametangial position Apical clusters Apical clusters (leafy forms) or on upper surface of thallus Sunken in thallus, scattered

Stomates Present on sporophyte capsule.Absent in both generations Present in both sporophyte and gametophyte.

Seta Photosynthetic, emergent from gametophyte early in development Hyaline, elongating just prior to spore release Absent.

Capsule Complex with operculum, theca and neck; of fixed size Undifferentiated, spherical or elongate; of fixed size Undifferentiated, horn-shaped; growing continuously from a basal meristem.

Sterile cells in capsule Columella.Spirally thickened elaters Columella and pseudoelaters.

Capsule dehiscence At operculum and peristome teeth Into 4 valves Into 2 valves.

a. Gametophyte CharacteristicsMoss life cycle begins when haploid spores are released from a sporophyte capsule and begin to germinate. In the majority of mosses, germination is exosporic, i.e., the spore wall is ruptured by the expanding spore protoplast after its release from the capsule and prior to any cell division. However, in some mosses, e.g. Andreaea, Drummondia, and Leucodon, germination is precocious and endosporic, meaning that cell divisions occur prior to spore release and spore wall rupture, respectively. There are variations in patterns of germination of moss ( K. Nehira 1983). In most mosses, a highly branched filamentous, uniseriate protonema are formed.

Cell specialization occurs within the protonema as a result two types of filaments are formed:-

a horizontal system of reddish brown,anchoring filaments (rhizoids), called the caulonema

upright, green filaments, the chloronema.

Each protonema can spread over several centimeters, forming a fuzzy green film over its substrate. Usually this protonemal stage is short-lived, but in a few taxa, e.g., Buxbaumia it persists as the vegetative phase of the plant.

Formation of bud apical cells: As the protonema grows, target cells usually on the caulonema generate bud initials that will ultimately divide by sequential oblique divisions to form bud apical cells. This initiates the growth of the leafy gametophore or shoot stage of the moss.

b. Shoot Morphology and Habit The leafy shoot continues to grow by mitotic division of its obovoidal to fusiform apical cell and surrounding meristem.

Divisions occurring in the apical cell form spirally arranged derivatives, each of which will give rise to a single leaf and a portion of the stem.

The angle of divergence between successive derivatives is responsible for the spatial arrangement of the leaves or phyllotaxy of the shoot.

Mature leaves of few mosses are clearly ranked; e.g., the leaves of Fissidens and Bryoxiphium are in two rows, a 1/2 phyllotaxy

Fontinalis and Tetraphis have leaves aligned in three rows, a 1/3 phyllotaxy.

In most mosses, however, the leaves are spirally distributed, with 2/5 and 3/8 phyllotaxies being most common.

The peristomate or true mosses (Superclass V) on the basis of position of the perichaetia and subsequent sporophytes have traditionally been divided into two broad morphological groups:-

1. Acrocarps :-Acrocarps are characterized by erect or ascending shoot systems that are either unbranched or only sparingly branched. Branching is typically sympodial with the branches morphologically comparable to the determinant main shoot from which they arise. Perichaetia are differentiated at the tip of the main or primary shoot and terminate its growth, so further plant growth occurs only if a branch is produced below the perichaetium; such branches are called subfloral innovations

2. Pleurocarps are generally characterized by creeping shoot systems, with extensive lateral branching.In such systems, the indeterminant main stem may be morphologically distinct from the secondary and tertiary level branches that arise from it (C. La Farge 1996). Perichaetia in pleurocarps are produced at the tips of very short, basally swollen lateral branches that are very short, morphologically distinct from the vegetative branches.

Cladocarpic mosses produce perichaetia at the tips of unspecialized lateral branches that display the same heteroblastic leaf series as the vegetative branches. Such branches are themselves capable of branching, and these mosses are neither acrocarpic nor pleurocarpic.

Pleurocarps form a natural, monophyletic lineage of true mosses (B. Goffinet and W. R. Buck 2004), but cladocarpy has evolved in several different lineages.

The main stems of Sphagnum (Superclass II) display a furcate or dichotomous branch architecture (H. A. Crum 1984).

c. Rhizoids

Mosses are anchored to their substrates by filamentous, often branched, reddish brown rhizoids, except Takakia and Sphagnum. The rhizoids (As in caulonemata) are multicellular with oblique cross walls; their walls are smooth or roughened with papillae.

Most rhizoids are slender and only sparingly branched (micronematal type) arise from any of the epidermal cells of the stem.

But others are larger in diameter and extensively branched (macronematal type) and is associated only with branch primordia.

They function primarily as anchoring structures . Rhizoids are not major sites of water and nutrient uptake, but can enhance capillary movement of water along the outer surface of the stem (M. C. F.Proctor 1984).

d. Stem Anatomy In many mosses, the stem is anatomically complex, consisting of a differentiated epidermal layer, a cortex, and a central strand of thin-walled, hydrolyzed water conducting cells, called hydroids.

e. LeavesConsiderable variation in the arrangement and structure of moss leaves provides some of the most morphologically useful characters for species identification.