Division Pterophyta et. al. Ferns and their allies

Vascular Seedless Plants - (Ferns and their Allies) I Vascular Seedless Plants - (Ferns and their Allies) I. Introduction General Characteristics A. Xylem and Phloem present B. Spores present but no seeds!

II. Classification A. Division Psilosophyta (Whisk Ferns) 1 II. Classification A. Division Psilosophyta (Whisk Ferns) 1. NO leaves or roots B.Division Lycopodophyta (Club Mosses and Quillworts) a. Very small underdeveloped leaves known as microphylls. b. Selaginella and Lycopodium are in this division. C. Division Sphenophyta (Equisetophyta) (Horsetails & Scouring Rushes) a. Also have underdeveloped leaves known as microphylls. b. Best example is Equisetum

D. Division Pterophyta (Ferns) 1 D. Division Pterophyta (Ferns) 1. Large complete leaves known as megaphylls 2. In ferns, these pinnate megaphylls are known as fronds. 3. Emerging fronds known as fiddleheads. Some are edible; others are not.

III. Division Psilophyta - (The Whisk Ferns) A. Structure and form Evenly forked stems which are photosynthetic No roots or leaves Flattened enations or preleaves are present- not yet true leaves. Two genera in division Psilotum - Tmesipteris –

Whisk fern (Psilotum) Notice the flattened enations. With attached sporangia

B. Reproduction of Whisk ferns Small sporangia borne on short stubby branches Meiosis occurs in sporangia producing meiospores Meiospores germinate slowly in soil or on bark of tree ferns Gametophytes found beneath the soil and are very small Archegonia and Antheridia produced on this colorless gametophyte Fertilization occurs inside the archegonium Sporophyte develops from the zygote.

IV. Division Lycopod0phyta – (The club mosses and quillworts.) A .Lycopodium – ground pines 1. Structure and form Evergreen herbs Many tropical forms Dichotomously branched stems Small leaves called microphylls

2. Reproduction Strobilus, or cone like structure formed in many species Sporophylls have sporangia, where the meiosis occurs Meiospores germinate in the soil and produce gametophytes, each of which has archegonia and antheridia Fertilization occurs in archegonium, producing a zygote Zygote develops into mature sporophyte Asexual reproduction may occur by bulbils, small budlike structures in leaves  

Lycopodia (Ground Pines) strobila sporophyte

B. Selaginella – spike mosses 1. Structure and form a. Filmy ground covers in tropical forests b. Extra appendage, called ligules, present on leaves c. They produce Heterospory, or two different sexual spores 2. Reproduction a. Separate male and female gametophytes Microspores – male gametophytes Megaspores – female gametophytes  

Selaginella lepidophylla

V. Division Sphenophyta - (Equisetophyta ) A. Structure and Form 1. Equisetum = means horsetail a.Branching forms called horsetail b. Non-branching forms called scouring rush 2. Silica content of stems = Colonial “brillo pads” used to clean pots 3. Herbaceous 4. Whorls of branches and/or leaves (Microphylls) 5. Stems distinctly ribbed 6. Central canal system hollow = used by Native Americans to sneak up on enemies

Equisetum (horsetail or scouring rush)

B.Reproduction 1. Cones or strobili formed 2. Sporangiophores bear the elongated sporangia 3. Spores produced by meiosis in the sporangia 4. Spores germinate and produce green cushion-like gametophytes 5. Male and female gametophytes formed; females become bisexual after 4-6 weeks  

Equisetum

This is the spore producing strobilus of Equisetum.

VI. Division Pterophyta – The True Ferns A. Structure and form 1 VI. Division Pterophyta – The True Ferns A. Structure and form 1.Tiny floating aquatic forms to giant tropical tree ferns 2.Large megaphyll leaves called fronds 3.Young coiled leaves called fiddleheads; Some are edible; others are not. 4.Underground stems called rhizomes 5. Abundant in tropical climates; fairly common in subtropical climes like ours.

B. Reproduction 1. Fronds bear sporangia in clusters called sori on underside. 2. Meiosis occurs in sporangia 3. Spores violently ejected from sporangia 4. Spores grow in heart shaped gametophyte called a prothallus. 5. Archegonia and Antheridium produced on gametophyte (prothallus) 6. Fertilization forms zygote, which grows into embryo 7. Embryo forms new fern plant called a sporophyte (dominant stage) 8. Fronds contain a pinnate form of leaf division.

Sori on the underside of fern fronds.

That’s all folks!