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Lycopodium exhibits Isotomous and Anisotomous Branching.

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Perfect Isotomous Branching

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A local species (Lycopodium phyllanthum) with Isotomous Beanching & large Microphylls

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A prostrate form with Anisotomous Branching

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You are looking at the top of a perennial Lycopodium. The new growth is yellow-green. Identify the Branching pattern!

The Leaves are Microphylls and have a single Vascular Bundle that is connected to the Stele in the stem by Leaf Traces. The latter can be seen in the Cortex of the Stem.

Stomata are present. The Mesophyll (middle leaf) is undifferentiated and has a uniform appearance.

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Some species are Isophyllous while others are Anisophyllous.

Leaves associated with Sporangia are called Sporophylls. These can be similar to vegetative leaves or they may be distinct. The latter occurs when the sporophylls are assembled into a Cone (Strobilus).

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In some cases complex Gemmae are produced in place of leaves. They have preformed Shoot and Root Apical Meristems plus vegetative leaves & readily produce new plants when they land in a favorable environment.

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Alpine plant with Gemmae - These could be handy in a challenging environment where the next Lycopodium could be on the opposite side of the valley.

In some cases Complex Gemmae are produced in place of leaves. thwae have preformed shoot and root Apical Meristems plus vegetative leaves & readily produce new plants when they land in a favorable environment.

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Lycopodium phyllanthum Vegetative Leaves

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The Yellow areas along these stems have Sporangia at the base of each leaf. Otherwise the Sporophylls are identical to vegetative Leaves.

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This a close-up which shows the bean-shaped Sporangia at the base of Isophyllous Sporophylls.

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SEM photo of Lycopodium-type Sporangia Shamelessly colored by DTW.

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The Vegetative leaves in this species are needle-like. The sporophylls of the cone are greatly reduced in size and have a different shape.  The leaves are thus Anisophyllous.

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Macrophoto of a Gemma

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Microphoto of a Gemma

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