For a simple leaf with a pointy apex, is “leaf length” : A. the distance along the leaf axis from the point of attachment (e.g. to a petiole or directly to the stem) to the leaf apex? or B. the distance from the basalmost-edge of the lamina of a leaf to the leaf apex, along an imaginary line para…

In general, if not specified otherwise, leaf length would include all parts of the leaf including the petiole (if any), starting at the point of attachment, but generally not including any lobes that extend “behind” the point of attachment. If the measurement is referring only to a part of the leaf…

Thanks for the reply. It’s counterintuitive to me that statements like “leaves 2x longer than broad” would include the petiole, for example. They must mean the blade in at least that instance, no? I guess I’ll have to do the hard work of trying to find examples of plants this author has personally i…

EDITED initial question to reflect answer by @jdmore that the petiole length is in fact, generally included: For a simple leaf with a pointy apex, what is “leaf blade length”: ? A. The distance along the leaf axis from the point of attachment (e.g. petiole or directly to the stem/twig) to the leaf…

As you most likely already know but is worth mentioning again and again is that leaf size is usually low on the list of plant identifiers— it’s often highly variable depending on a number of factors but especially amount of sunlight, soil nutrients, and water available. Two plants of the same specie…

[image] ddennism: People who write keys: This is extremely frustrating to the uninitiated! Keys can be extremely frustrating even to the initiated ;)

I run into relative organ lengths all the time in keys.

Yes, I find that length:width ratio (a rough proxy for leaf shape) is often much more consistent within a species than absolute size.

Agree. Even shape, as I saw in the statement “leaves 2x longer than broad” can be not really true if there is more sunlight, less humidity in the air, a water source near… I see this pretty often as I started noticing varying populations of Rauvolfia tetraphylla in my “happy place” of observations.

Leaf length convention

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Leaf length convention

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