# Leaf abcission scars/lumps

**URL:** <https://forum.inaturalist.org/t/leaf-abcission-scars-lumps/8098>\
**Category:** Nature Talk\
**Created:** [November 20, 2019, 4:59am UTC](https://forum.inaturalist.org/t/leaf-abcission-scars-lumps/8098 "2019-11-20T04:59:38Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![coniontises](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/coniontises/32/24854_2.png) [@coniontises](https://forum.inaturalist.org/u/coniontises)\
**Post date:** [November 20, 2019, 4:59am UTC](https://forum.inaturalist.org/t/leaf-abcission-scars-lumps/8098/1 "2019-11-20T04:59:38Z")

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Just curious, does anyone know why the stems of habitual leaf-dropping plants (classic example: Plumeria spp. and long-stemmed Crassulaceae) become so lumpy from the progressive accumulation of decommissioned “leaf-attachment-point warts” and their associated scars? I suspect it may just be the result of “sloppy” evolution (plant stuck at local optima; physiologically difficult to resorb the lumps) but I am unsure whether this is actually the case; I could not find any published research on the topic.

Thanks

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**Author:** ![arboretum\_amy](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/arboretum_amy/32/2328_2.png) [@arboretum\_amy](https://forum.inaturalist.org/u/arboretum_amy)\
**Post date:** [November 20, 2019, 3:45pm UTC](https://forum.inaturalist.org/t/leaf-abcission-scars-lumps/8098/2 "2019-11-20T15:45:37Z")

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What would be the evolutionary advantage of smoothing the scars? The plant doesn’t care what it looks like!

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**Author:** ![coniontises](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/coniontises/32/24854_2.png) [@coniontises](https://forum.inaturalist.org/u/coniontises)\
**Post date:** [November 20, 2019, 3:51pm UTC](https://forum.inaturalist.org/t/leaf-abcission-scars-lumps/8098/3 "2019-11-20T15:51:49Z")

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Tissue optimization? After all mammal scar tissue is known to be slightly inferior to uninjured stuff structurally.

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**Author:** ![neontetraploid](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/neontetraploid/32/1284_2.png) [@neontetraploid](https://forum.inaturalist.org/u/neontetraploid)\
**Post date:** [November 20, 2019, 6:16pm UTC](https://forum.inaturalist.org/t/leaf-abcission-scars-lumps/8098/4 "2019-11-20T18:16:54Z")

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Protection from pests that might use the former attachment site as an easy way to enter the plant maybe? I’d imagine scar tissue is a lot tougher to get through than vascular tissue

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**Author:** ![paulexcoff](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/paulexcoff/32/8236_2.png) [@paulexcoff](https://forum.inaturalist.org/u/paulexcoff)\
**Post date:** [November 20, 2019, 8:03pm UTC](https://forum.inaturalist.org/t/leaf-abcission-scars-lumps/8098/5 "2019-11-20T20:03:54Z")

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It’s not “scar tissue” in the plant, it’s the original tissue that formed as the leaf did.

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**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/inaturalist/original/2X/7/7831452cf7f0d653ff1ffd34176334b7ef1b6a17.png) [@system](https://forum.inaturalist.org/u/system)\
**Post date:** [January 19, 2020, 8:03pm UTC](https://forum.inaturalist.org/t/leaf-abcission-scars-lumps/8098/6 "2020-01-19T20:03:55Z")

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