BRYOPHYTES The LIVER WORTS plant body is thalloid

BRYOPHYTES

� The LIVER WORTS plant body is thalloid. E. g. , Marchantia

THALLUS � Thallus is dorsiventral. Leafy members have tiny leaf like appendages in two rows.

� By ASEXUAL REPRODUCTION fragmentation of thalli. � By specialised structures called gemmae –green, multicellular, asexual buds – in small receptacle called gemma cups. gemmae detach and germinate to form new individual. .

SEXUAL REPRODUCTION � Male and female sex organs are produced on the same or different thalli.

SPOROPHYTE � Differentiated into foot, seta and capsule. � Spores produced within the capsule. � Spores germinate into free – living gametophyte.

MOSSES � Predominant stage is gametophyte. First stage protonema –creeping, green, branched, filamentous stage.

LEAFY STAGE � Develops from secondary protonema as lateral bud – upright, slender axes bearing spirally arranged leaves. Attached to soil by multicellular, branched rhizoids.

VEGETATIVE REPRODUCTION � By fragmentation and budding in secondary protonema.

SEXUAL REPRODUCTION � Antheridia and archegonia is produced at the apex of leafy shoots. � After fertilisation zygote develops into sporophyte.

sporophyte � Consists of foot , seta and capsule. � Capsule contains spores formed by meiosis.

� Includes Pteridophyte ferns and horse tails.

FERNS

� Main SPOROPHYTE plant body is sporophyte – differentiated into true root, stem and leaves. � Vascular tissues well-differentiated.

� Small LEAVES (microphylls) – selaginella or large (macrophylls) - ferns

� Leaf-like SPOROPHYLL appendages which bear � sporangia – sporophylls. � Sporophylls form strobili or � cones. � sporangia produce spores by � meiosis in spore mother cell. � Spore develops into small, � multicellular, free-living � photosynthetic thalloid � gametophyte-prothallus.

� Bear GAMETOPHYTE male and female sex organs – antheridia and archegonia. � Male gamete-antherozoid fuses with female gamete – zygote � Zygote develops into sporophyte.

� Homosporous. spores heter 0 sporous. -megaspores, microspores – develop into female and male gametophyte – female gametophyte retained in the sporophyte. � Zygote develops into embryo within the female gametophyte.