Leaf width environmental or strain related?

lve always wondered why my sativa dom cross breeds always have fat leaves, well after watching a video by Dr Bruce Bugbee of apogee instuments inc. I think it might be environmental. I dont live in a dry arid environment, thin leaved plants thrive in these environments as they disperse heat easier than fat leaved cousins. No need for that here. Elevation, humidity and temperature are all involved.
The next time you grow a fat leaved sativa you might know why it is what it is. Always thought it was something in the breeding, but now l know its about environment, cooler temps fatter leaves.
Some will dissagree but would like to hear your take on this too, lve been wrong so many times once more wont kill me. Thanks to those who add 2 cents ahead of time. Be safe and grow mòrè.

Long as it's sweetleaf i dont mind.(nudge nudge wink wink)

I always thought the two different leaf types evolved in different conditions . Thin leaf sativas were in dry conditions so the thin leaves conserved water. Fat leaf indicas developed in more tropical conditions, so they could use as much water as they wanted.

Cousin_suds said:

I always thought the two different leaf types evolved in different conditions . Thin leaf sativas were in dry conditions so the thin leaves conserved water. Fat leaf indicas developed in more tropical conditions, so they could use as much water as they wanted.

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Thai strains and other sativa's from Central and South America have thin leaves yet they grow in tropical climates. Dry climates like the Middle East, Turkey, Morocco, etc... have plants with wide leaves. In some places you'll find plants that display both types of leaves. Afghanistan is far from a tropical climate yet it has some of the finest fat leaved indica's in the world.

ok my take is that fatter leaves can act as water storage units for plants in a dryer climate because stomas can be closed by the plant to control evoporation and it can conserve water that way and with tropical sativas they got plenty of moisture when ever they like it so the leaves don’t need to act as water tanks thus the thin leaves. this is my theory and understanding tho, never really looked into it.

PJ Diaz said:

(PDF) Cannabis Taxonomy: The "sativa" vs. "indica" debate

PDF | On Jan 30, 2018, Robert C. Clarke and Mark D. Merlin published Cannabis Taxonomy: The "sativa" vs. "indica" debate | Find, read and cite all the research you need on ResearchGate

www.researchgate.net

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I've read that article. In my previous post I was referencing what the majority of people consider sativas. I've never referenced it because there is still some disagreement in the scientific world and bringing it up has the potential to be ridiculed by the cannabis broscience warriors that would rather believe some cannabis website that says differently.

But basically what everyone is growing these days even what people refer to as sativa are indica just different subspecies. Sativa is actually hemp per that article.

crimsonecho said:

ok my take is that fatter leaves can act as water storage units for plants in a dryer climate because stomas can be closed by the plant to control evoporation and it can conserve water that way and with tropical sativas they got plenty of moisture when ever they like it so the leaves don’t need to act as water tanks thus the thin leaves. this is my theory and understanding tho, never really looked into it.

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Personally I think a more plausible hypothesis is that leaf width is generally based on longitude. Since equatorial strains have more intense sunlight and longer days, there isn't as much need for leaf area to allow the plant to photosynthesis as there is in higher latitudes, where coincidentally the leaves are wider, likely because of less intense and decreased daylight.

xtsho said:

I've read that article. In my previous post I was referencing what the majority of people consider sativas. I've never referenced it because there is still some disagreement in the scientific world and bringing it up has the potential to be ridiculed by the cannabis broscience warriors that would rather believe some cannabis website that says differently.

But basically what everyone is growing these days even what people refer to as sativa are indica just different subspecies. Sativa is actually hemp per that article.

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Yeah, I agree with that, but at the same time I believe that Robert C Clarke is still pretty much the leading foremost expert on Cannabis botany out there. Legend. Who's gonna argue with a legend?

PJ Diaz said:

Personally I think a more plausible hypothesis is that leaf width is generally based on longitude. Since equatorial strains have more intense sunlight and longer days, there isn't as much need for leaf area to allow the plant to photosynthesis as there is in higher latitudes, where coincidentally the leaves are wider, likely because of less intense and decreased daylight.

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why not? seems plausible

PJ Diaz said:

Yeah, I agree with that, but at the same time I believe that Robert C Clarke is still pretty much the leading foremost expert on Cannabis botany out there. Legend. Who's gonna argue with a legend?

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I'm not going to argue with the article as it makes sense to me. The problem is that for decades cannabis growers have had set criteria for identifying indicas and sativas based on the leaves. Getting many to change that thinking is not going to happen overnight. Especially since all many have known is that a cannabis website said wide leaf = indica and narrow leaf = sativa.

That article was first published in 2016 by the American Botanical Council which was founded by Mark Blumenthal whose biography is rather impressive.

Here's a link to the same article published in issue 110 of Herbalgram which is a peer reviewed quarterly journal put out by the American Botanical Council. The advisory board for the council is pretty impressive with most of the members having PhD's.


http://herbalgram.org/resources/herbalgram/issues/110/table-of-contents/hg110-feat-cannabistaxonomy/

"Since the 1960s, most of the drug Cannabis that reached North America and Europe was C. indica subsp. indica. Marijuana users commonly call domestically grown plants of these varieties “sativas” because their leaflets are relatively narrow, and therefore exhibit a superficial resemblance to those of European NLH plants. However, in our construct, this is a misnomer as C. sativa plants produce little if any THC. Based on Hillig’s research, we now refer to members of C. indica subsp. indica as narrow leaflet drug (NLD) varieties. Although they have relatively narrow leaflets like NLH (C. sativa) plants, the NLD plants can produce an abundance of THC and are most commonly used for their psychoactive effects. Based on taxonomic tradition, these plants are properly called “indicas” rather than “sativas.”"

the more i think about it i realize that there must be more than one reasons which makes one morphology dominant over the other.
i agree with @PJ Diaz but also thinking fatter leaves and dense indica canopy in tropical areas could significantly increase the chances of getting mold too, so probably plants with this particular trait never had the chance to become dominant in tropical areas as their flowers would rot and wouldn’t be able produce seeds.
i’m pretty sure there must be other causes to this but this also seems plausible to me. natural selection.