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Commisural Bundles are very abundant & prominent in the leaf of
Maranta (Prayer Plant) |
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Monocots have a Network of Veins! The prayer plant (Maranta), ki & Traveler's Palm exhibit several vein traits which point out the limitations of the generalization that Monocots have only Parallel Venation and that their venation does not form a Network like Reticulate Venation. All of the above have Commisural Bundles which results in a close-knit pattern of veins that rivals the contact between veins and the mesophyll seen with Reticulate Venation. Furthermore, ki and Maranta have apparent "Midribs" and there are "lateral" veins which diverge from them in a pinnate-like pattern (Maranta). These midribs may not contain extremely enlarged veins but they contain many large parallel veins. Finally, the veins converge and join near the leaf margin forming a closed, integrated vascular system. The pattern seen in Maranta is called Pinnate-Striate. |
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The numerous vascular bundles in the Midrib are evident. The prominent, fibrous Bundle Sheath is evident in the right-hand image. This provides mechanical strength for the lamina and prevents the disruption of the major veins by physical trauma.
What is the venation of Caladium?
Anthurium which is closely related to Caladium
and has similar venation. |
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Cross-section of Anthurium Leaf : Note the Palisade & Spongy Mesophyll which resembles that seen with some Dicots.
The Mesophyll of ki leaves is uniform and lacks cellular specializations like those seen above. |
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 Monstera |
 Taro |
| More monocot leaves that have Pinnate Striate Venation! The term Striate is preferable to Parallel when Venation in Monocots is considered. |
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| Dichotomous
Venation in a Filmy Fern
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Dichotomous Venation is characterized by veins which fork at their apex and produce 2 veins of the same size. The branches can develop equally or unequally. The minor veins tend to have the same size rather than getting progressively smaller. |
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