| Diversity |  |
| One Genus - Equisetum "HorseTail" |
|
Equisetum was present in the Carboniferous -> Little
Change Today |
|
| 15 Species | |
| Occurrence & Distribution |  Equisetum in the Arctic Alpine Zone Jasper Canada |
| World-wide (Except Australia & N. Zealand) |
|
| Tropical -> Arctic |
| Habitat |
|
| Small | |
| E. scirrpoides | |
| Ht. = 4-5 cm | |
| Dia. = 0.5 cm | |
| E. giganteum |
|
| Ht. = 8 m | |
| Dia. = 2 cm | |
| Terrestrial | |
| Moist Areas (Shallow) | |
| Streams | |
| Lakes | |
| Accumulate Heavy Metals | |
| Indicator Plants -> Pollution | |
| Gold Prospecting (4.5 oz/ton) |
| Morphology | |
| Aerial Stems & Rhizomes |  |
| Grooved | |
| Jointed | |
| Nodes & Internodes | |
| Leaves |  Leaves are fused and form a sheath around the stem at each node. The number of tips signifies the number of leaves. |
| Microphylls Each Leaflet has one leaf trace which connects with the stele in the stem |
|
Whorled Arrangement |
|
| Branches |
|
| Lateral | |
| Monopodial One Axis |
|
| Stem Anatomy |  |
Apical Meristem = Apical Cell Minor Amount of Axis Length |
|
| Intercalary Meristem |  Intercalary Growth in Equisetum - Note that the diameter of the stem Increases above the node. This is exactly the opposite for most stems. Choose a Cell File and Follow it. Where is there evidence of mitosis? Where does cell elongation commence? |
| Located at the Nodes | |
Responsible for Most Stem Elongation |
| Intercalary
Growth as Seen in Australia. Ah!! This looks Righto!! Perhaps this should be called Down Under Growth
Hey There are lots of strange phenomena from that part of the globe!!!! |
 |
| Internet
Flash Bizzare Plant found at the base of Ayar's Rock. Scientists are baffeled by the fact that the fossil appears to be a "two toned" structure. Too Right!!!! |
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| Internodes Hollow Canals Cells Destroyed by Elongation Node = Solid Septum |
|
| Epidermis Thick Walls Cutenized Rough Surface = Silicon Ridges Silicified Little Lignin Silicon Required for growth Stomata In Grooves Sunken |
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|
| Cortex |
|
| Sclerenchyma (Ridges) | |
| Cortical (Vallecular) Canals | |
| Collenchyma | |
| Chlorenchyma | |
| Endodermis |  Note the Pink Casparian Strip |
| Continuous on both sides of stele | |
| Surrounds individual bundles |  Locate the Casparian Strip |
| Continuous on outside of stele |
| Vascular Bundles |  Cross Section of Equisetum Stem |
| Opposite
Ridges Eustele |
|
| Vascular (Carinal) Canal is caused by
the destruction of Protoxylem during Elongation It actually Conducts Water, however, this can't be very Efficient. Ah, Another potential Student Research Project! |
|
 |
| Metaxylem |  |
| Bracket Phloem | |
| Endarch Maturation | |
| Tracheids -> Vessel Members | |
| Annular Rings -> Bordered Pits | |
| Primitive -> Advanced Traits |
| Phloem | |
| Opposite Xylem |  |
| Maturation = Exarch | |
| Metaphloem | |
| Larger Diameter | |
| Near Carinal Canals | |
| Sieve Cells Resemble Flowering Plants | |
| Callose in Pores | |
| Node -> | |
| Papery
Leaves occur, however, they are not well developed for photosynthesis. Microphylls |
 |
| Rhizomes | |
| Covered by Leaves | |
| Branching occurs at the Nodes. Root Meristems are also present. This allows one stem segment to produce a new plant. |
|
| Tubers can be present. These are used for Storage and asexual propagation | |
| Vegetative Propagation | |
| Roots | |
| Embryo -> Ephemeral Root |
|
| Most Roots are formed at Nodes = Adventitious | |
| Root Anatomy | |
| Apical Meristem = Apical Cell | |
| Epidermis | |
| Endodermis -> Lateral Roots | |
| Stele | |
| Actino |  |
| Exarch (2-6 arms) | |
| 2 = Diarch | |
| 3 = Tri | |
| 4 = Tet | |
| 5 = Pent |  Stele in a Large Equisetum Root |
| 6 = hex | |
| Central Metaxylem Cells = Exarch Dev. | |
| Phloem between Xylem arms | |
| Leaf Anatomy |
| Fused Microphylls |
| 5-20 Leaves |
| Abaxial Epidermis = Thick |
| Mesophyll = Air Spaces "Lacunae" |
| Little Chlorophyll |
| Sporangia Strobilus (Cone) |  |
| Terminal | |
| Main Axis |  |
| Separate Vascular Bundles | |
| No Canals |
| Sporangiophores -> Cone | |
| Sporangiophores Whorled
Short Stalk
Flattened Terminal Disk Umbrella-Like
Sporangia
Longitudinal Dehiscence
Outer Wall Helical Thickenings Swell & Contract Spore Dispersal |
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| Spores | |
| Spherical Homosporous Outer Wall = Elaters Strips Expand & Contract Elbow Way out of Sporangium Chloroplasts Present (Unusual) Short Lived = Days |
|
|
|
| Gametophyte | |
| Require Moisture |  Early Stage Gametophytes |
| Chlorophyllous Autorophic | |
| Exosporic | |
| Ephemeral | |
| (Perennial in Lab) |  Young Gametophyte with Antheridial Lobes |
| Small (1 mm -> 5 cm) |
|
| Prostrate | |
| Body = Multistratose | |
| Margins = Flaps (Laminar) | |
| NO VASCULAR TISSUE | |
| Gametangia | |
| Antheridium |  Equisetum Antheridium |
| Embedded | |
| "Male" Gametophytes | |
| Grow Slowly | |
| Lobes -> Antheredia | |
| Multiflagellar Sperm | |
| Archegonia Present with Age | |
| "Female" Gametophytes | |
| Archegonia |  |
| Elongated Terminal Neck Cells | |
| Base of Upright Lobes | |
| Antheredia Present with Age | |
| Self-Fert. = Rare (Electrophorersis) | |
| Fertilization Requires Water | |
| Embryo | |
|
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| Exoscopic Several
Sporophytes/ |
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