Bryophytes 1

Bryophytes Ubiquitous Important colonizers with lichens Moist temperate and tropical locations Dominate Arctic Tundra Antarctica Above the treeline Dry deserts Some aquatic Important colonizers with lichens Sensitive to air pollution

Hypnum sp. - Moss on fallen log. GSMNP Nowellia LEAFY LIVERWORT Lichen Photo by Alan Heilman Hypnum sp. - Moss on fallen log. GSMNP

Bartramia pomiformi (apple moss) + Peltigera, a lichen. Photo by Alan Heilman

Features shared with Charophytes Coleochaete -Unicellular flagellated green algae Chara -Filamentous green algae Other Plants Hornworts Liverworts Mosses Features shared with Charophytes Multicellular specialization (tissues) Cell walls made of cellulose Pigments: a. Chlorophyll a b. Chlorophyll b Primary storage substance: starch Oogamous -- Male gamete is motile & asymmetrical Breakdown of nuclear membrane Zygotes retained Other algae

Ability to distinguish D-methionine from L-methionine Coleochaete -Unicellular flagellated green algae Chara -Filamentous green algae Other Plants Hornworts Liverworts Mosses Xylem and phloem Outer layer on spores Stomata Ability to distinguish D-methionine from L-methionine Zygote retained by gametophyte Flavenoids

Bryophytes Transitional between Charophytes and Vascular Plants Synapomorphies for land plants Antheridia and archegonia with protective layer Retention of zygote & multicellular embryo Presence of multicellular diploid sporophyte Multicellular sporangia Meiospores with sporopollenin Apical meristem

Bryophytes “Autapomorphies” Lack of xylem and phloem No lignin Gametophyte generation dominant; free-living Sporophyte nutritionally dependant Sporophyte unbranched with single sporangium

Ubc.edu

Bryophyte Structure Thalloid -- Hornworts & (some) liverworts Differentiated -- Mosses & (some) liverworts Not true leaves/stems Gametophyte generation No xylem & phloem Rhizoids Mosses – multicellular Liverworts & hornworts – unicellular Only anchor plant Plasmodesmata

Bryophyte Structure Hornworts – single plastid Sperm only flagged cell – water required Gemmae cups Gametophytes often sexed Sex chromosomes 1st in bryophytes! Photo by Alan Heilman

Reproductive Structures Antheridium Each cell  single sperm

Reproductive Structures Archegonia Single egg Zygote persistent Matrotrophy Enlarged venter  calyptra

Nearly Mature Sporophyte

Embryophytes Matrotrophy + placenta  multicellular sporophyte (produced by …… More divisions between fertilization and meiosis Larger sporophyte More spores Sporophytes of hornworts & mosses  stomata Sporopollenin – survival value Spore generates  protonema

THE PHYLA OF BRYOPHYTES The three phyla are: Bryophyta – Mosses ca. 10,000+ sp. Hepatophyta – Liverworts ca 6000 sp. Leafy liverworts Thallose liverworts Anthophyta – Hornworts ca 100 sp.

Liverworts: Phylum Hepatophyta Ca. 6000 species Mostly terrestrial Some have protonema-like structure Apical meristem 3 major groups Complex thalloid liverworts Simple thalloid liverworts Leafy liverworts

Complex Thalloid Liverworts Marchantia, Riccia, Ricciocarpus Terrestrial Thallus 10-30 cells thick Upper layer -- air pores Middle layer -- chloroplast rich Lower layer – carbohydrate storage & rhizoids

Riccia sporophytes Little more than a sporangium

Marchantia sporophytes Gametangia -- stalked specialized structures Sporophyte – foot, seta, and capsule

Conocephalum conicum - thallus + archegoniophore, with dev. sporophyte archegoniophore (part of gametophyte, not a sporophyte) Photo by Alan Heilman

Marchantia Mature capsule contains elaters (green strands) Aid in spore dispersal

Asexual Reproduction Fragmentation Gemmae – splash cups

Marchantia Life Cycle

Marchantia polymorpha - antheridiophores male Photo by Alan Heilman Marchantia polymorpha - antheridiophores male

Marchantia polymorpha - archegoniophores female Photo by Alan Heilman

Ricciocarpus natans - floating aquatic liverwort Photo by Alan Heilman Ricciocarpus natans - floating aquatic liverwort

Riccia fluitans - floating aquatic liverwort Photo by Alan Heilman Riccia fluitans - floating aquatic liverwort

Conocephalum conicum - detail of upper surface of thallus with pore Photo by Alan Heilman Conocephalum conicum - detail of upper surface of thallus with pore

Leafy Liverworts Very diverse More tropical Diagnostic … > 4000 of the 6000 species More tropical Diagnostic … Moss leaves Spiral Midrib Entire Liverwort leaves Distichous Highly dissected

Photo By Paul Davison Frullania

Photo By Paul Davison Cephalozia

Moss and Liverwort Leaves Leafy Liverwort Margin teeth Mid Vein Moss and Liverwort Leaves

Sporophyte of leafy liverwort Capsule Seta Photo by Alan Heilman

Hornworts: Phylum Anthocerophyta ca 100 species Gametophytes similar to liverworts Large single chloroplast Phylogenetically most closely related to vascular plants Nostoc is symbiont -- N

Gametophytes Rosette-like Unisexual and bisexual Clustered antheridia Single gametophyte – many sporophytes wikipedia

Sporophytes

Sporophytes

Life cycle wikipedia

Anthoceros laevis - hornwort, habitat view

Photo by Ken McFarland Phaeoceros sp.

Mosses: Phylum Bryophyta Things that are NOT mosses …. Reindeer moss – lichen Scale moss – leafy liverworts Club moss – Lycopodium (Fern ally) Spanish moss – bromeliad (like pineapple …..) Spike moss – Selaginella (Fern ally) Sea moss (or Irish moss) – red alga (Carrageenan!)

Mosses: Phylum Bryophyta 3 groups discussed in text Sphagnidae – peat mosses Andreaeidae – granite mosses Bryidae – true mosses

Peat Mosses – Sphagnidae Sphagnum Earliest diverging moss Unusual Protonema a “plate” w/ marginal meristem Distinctive leaf morphology Distinctive sporophytes Gametophytes -- clusters of branches Diapers and wound dressings 20x dry weight in water (cotton only 4-6x)

Sphagnum Unique leaf morphology Antheridia and archegonia at tips of specialized branches Unique sporophyte morphology

Granite Mosses -- Andreaeidae Mountainous or Arctic regions Protonema & rhizoids – 2 rows of cells Unusual sporangial dehiscence

True Mosses -- Bryidae Filamentous protonema Multicellular rhizoids Leaves one cell thick Specialized tissues

Hadrom & Leptom Found in seta Water conducting tissue – hydroids Similar to tracheids no protoplast but no lignin Food conducting tissue – leptoids Similar to sieve tubes

Sexual Reproduction Male and female gametangia Branch tips Lateral branches Unisexual & bisexual Antheridia in splash cups Capsules – 6-18 months to mature! Maternally nourished sporophyte Specialized spore dispersal

Sexual Reproduction

Mnium Archegonia and Antheridia paraphyses

Antheridial Splash Cups

Peristome Teeth Control release of ~ 50 million spores Characteristic of Bryidae Taxonomically important

Eurhynchium serrulatum peristome teeth operculum calyptra Photo by Alan Heilman Eurhynchium serrulatum

Dicranella varia Dehiscing operculum Photo by Alan Heilman

Peristome teeth of Dicranum flagellaria Photo by Alan Heilman

Dicranella varia spores Photo by Alan Heilman

Grimmia gracilis peristome teeth open Photo by Alan Heilman