Kr bryophyta classification

Classification of Bryophyta as proposed by G.M.Smith

1. Bryophyta Classification (As Proposed by G M SMITH ) Dr. Kavita Rambal H.O.D Botany M.D.College, Parel Mumbai-12

2. Bryophyta Hepaticeae Anthocerotae Musci Sphaerocarpales Marchantiales Jungermanniales Calobryales Anthocerotales Division Class Sub class Sphagnobrya Eubrya Andreobrya Orders Sphagnales Andreaeles Eubryales (Polytrichales Funariales) ?

3. Derived from Latin word Hepatica means liver, thus the Hepaticeae are popularly known as liverworts. The vegetative thallus i.e , gametophyte is usually dorsiventral and is either a thallus (thallose) or a leafy axis (foliose), when foliose the leaves are without mid-rib. Rhizoids without septa. Each cell in the thallus contains many chloroplasts; the chloroplasts are without pyrenoid. Anatomically, the gametophyte is either simple or composed of many tissues. A photosynthetic tissues on the dorsal surface of gametophyte is always present and the cells forming it have numerous small chloroplast, without pyrenoids.

4. Sex organs are embedded in the dorsal surface, sex organs usually formed from a single superficial cell. Sporophyte may be simple (e.g., Riccia) having only a capsule, or differentiated into root, seta and capsule (e.g., Marchantia, Pellia and Porella etc.) Capsule lacks columella. The spores, on germination, usually directly or in some cases indirectly give rise to gametophytic thalli.

5. Source:Google Images

6. Hepaticeae Sphaerocarpales Calobryales Jungermanniales Marchantiales Sphaerocarpaceae Rielliaceae Ricciaceae Corsiniaceae Targionaceae Monocleaceae Marchantiaceae Metzgerineae Jungermaninae Haplomitriaceae or Calobryceae Orders Sub order Family

7. Sphaerocarpales Essentially lobate thallus. Thallus of parenchyma cells reclining or erect, with smooth-walled rhizoids; E ach sex organ surrounded by an enveloping sac. S porophyte spherical, lacking seta and elaters, opening by disintegration of the unornamented jacket cells; terrestrial except the aquatic Riella. sphaerocarpos sps Source:Google Images

8. Gametophyte thallus usually prostrate, dorsi ventral dichotomously branched thallus with a more or less marked midrib. Internal tissues are differentiated into two distinct regions - the dorsal and the ventral region. The dorsal, green region is assimilatory zone which generally encloses air spaces also called the air chambers. The air chambers communicate with the exterior generally through pores. The ventral region is composed of compact, colourless, parenchymatous storage tissue. Scales are usually present on the ventral surface of the thallus. Marchantiales Marchantia sps Source:Google Images

9. The ventral surface of the thallus bears scales and two kinds of rhizoids - smooth walled and tuberculate. The male & female sex organs are either scattered along the midrib or grouped in receptacles which are sometimes raised into the air. The sporogonium is simple in structure and small, either with or without seta. It has capsule wall one cell in thickness. Columella is absent. The capsule dehisces by various ways but never by four regular valves. Targionia sps Reboulia sps Source:Google Images

10. Marchantiales Ricciaceae Corsiniaceae Monocleaceae Marchantiaceae Targionaceae Riccia sps Corsinia Targionia Monoclea Marchantia

11. Commonly called Leafy liverworts also called  scale moss. The Jungermanniales have the plant body more complex than that of the Mar­chantiales. The sporophytes have multi-layered capsule walls and a general structure which is also more elaborate than that of the Marchantiales. S impler with thallose or simple foliose, prostrate gametophytes and apical growth . The stem generally has three rows of leaves along its length. one of these rows is much reduced in size and often have a distinctly different shape and are called  amphigastria . Jungermanniales

12. The mature gametophyte of the leafy liverwort can be either dioecious (each individual bears either male or female reproductive structures) or monoecious (each individual bears both male and female reproductive structures). The fertilized egg eventually develops into the sporophyte, which remains dependent on the gametophyte for water and nutrients. The sporophyte’s spore-containing capsule (sporangium) is usually attached to the gametophyte by an elongate seta. The sporangium ruptures and releases spores, which germinate, ultimately into the gametophyte. The gametophyte remains attached to the substratum by way of filamentous rhizoids (Smooth). Jungermanniales

13. Jungermanniales Metzgerineae Jungermaninae Sub Order Riccardia Fossombronia Metzgeria Blasia Pleurozia Chiloscyphus Plagiochila Cephalozia Porella Frullania

14. Calobryales Erect leafy gametophytes, leaves all alike. Antheridia are ovoid, stalked and apical. Archegonia differ from those of other Hepaticeae in that the jacket of the neck has only four vertical rows of cells. The sporophyte has an elongated capsule whose jacket layer is only one cell in thickness except at the apex.

15. Calobryales Haplomitriaceae Or calobryceae Haplomitrium Calobryum

16. Anthocerotae Gametophytic plant body is simple, thalloid; thallus dorsiventral without air cambers, shows no internal differentiation of tissues. Scales are absent in the thallus. Each cell of the thallus possesses a single large chloroplast with a pyrenoid. Antheridia develop from hypodermal cells on the dorsal surface. Archegonia completely embedded in gametophyte.

17. Anthocerotae Sporophyte is cylindrical only partly dependent upon gametophyte for its nourishment. It is differentiated into bulbous foot and cylindrical capsule. Seta absent meristematic. Endothecium forms the sterile central column (i.e., columella) in the capsule (i.e. columella is present).

18. Source:Google Images

19. Anthocerotales Gametophyte simple and dorsiventral. V.S thallus homogenous. Sporophyte differentiated into foot and capsule, seta absent. Columella present in the capsule.

20. Anthocerotales Anthocerotaceae Notothylaceae Anthoceros Notothylas

21. Gametophyte is differentiated into prostrate protonema and an erect gametophores. Gametophore is foliose, differentiated into an axis (=stem) and lateral appendages like leaves but without midrib. Rhizoids multi-cellular with oblique septa. Elaters are absent in the capsule of sporangium. The sex organs are produced in separate branches immersed in a group of leaves. Musci

22. Source:Google Images

23. Musci Sphagnobrya Eubrya Andreaeobrya Sub class Sphagnales Andreaeles Eubryales Sphagnum Eubrya Andreaea

24. Sphagnobrya They are called ‘bog mosses’ or ‘peat mosses’. The protonema is broad and thallose; It produces one gametophore; the leaves or gametophores lack mid-rib and usually composed of two types of cells- ( i ) the narrow living green cells and (ii) large hyaline dead cells. The branches arise in lateral clusters in the axis of the leaves borne on the stem.

25. The antheridia are borne in the axis of leaves on the antheridial branch. The archegonia are terminal and formed acrogenously. The Sporogenous tissue of a sporophyte develops from the amphithecium. The sporogonium remains elevated above the gametophyte due to elongation of a stalk of gametophytic tissue, the pseudopodium. Sphagnobrya

26. The plant body arises from the protonema. The midrib is not well developed in the leaves. Archesporium develops from amphithecium. The sporophyte is lifted up on the gametophyte by pseudopodium. The sporophyte consists of foot and capsule. The columella forms a roof over the spore sac. The capsule dehisces by the separation of lid. Sphagnales

27. The gametophores are brittle, and can easily be broken. There is practically no tissue differentiation in plant body. The leaves are generally large, erect and convolute. The archesporium and columella develop from the endothecium. Andreobrya

28. The protonema is ribbon or thallus shaped. Pseudopodium is well developed. The columella forms a roof over the spore sacs. The capsule dehisces by separation of lid. Lack of central conducting region in stem. Andreaeles

29. Plant body has leafy gametophore and dark brown or blackish in colour. Seta is insignificant. Elevation of capsule with the help of pseudopodium. Dome shaped spore sac over columella. Longitudinal dehiscence of the capsule into four or more valves. Andreaeles

30. The leaves of the gametophores are more than one cell in thickness and possess midrib on them. 2. The protonema are filamentous. 3. The sporophyte bears a well differentiated, elongated seta which pushes out the capsule from the gametophore. 4. The Sporogenous tissue is derived from the endothecium. 5. The archesporium does not overarch the columella; the columella continues up to the apex of the capsule; both columella and archesporium have been derived from the endothecium. Eubrya

31. 6. In between spore sac and columella, the partitioned air spaces are present. 7. The mature capsule possesses the complex structure made of many tissues. 8. The capsule opens at its apex by an operculum; the spore dispersal is regulated by a teeth like apparatus, the peristome. Eubrya

32. Gametophores differentiated into a. Prostrate Protonema b. Upright gametophore Gametophores branched or unbranched. Gametophore differentiated into stem and leaves. Vegetative reproduction by means of gemmae, primary protonema, secondary protonema etc. Eubryales

33. Young embryo differ from other bryophytes (two growing points). It is slender. Well developed Foot, seta and capsule. Upper part of the capsule matures into operculum and peristome. Number of teeth comprising the peristome is always four or a multiple . Spore germinates to form protonema. Protonema differentiated into a.chloronema or chloronemal branches b.rhizoids or rhizoidal branches Eubryales

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