It's Legume Week on iNaturalist! Apr 3 - 9, 2016


One of the most economically important families of plants, the Pea Family (Fabaceae) is used by humans mostly for its fruits, but this huge family of over 18,000 described species boasts beautiful flowers and wonderful compound leaves as well. We’re featuring this family on the Critter Calendar this week, so let’s dive in and learn what makes it special!


We’re all familiar with a pea pod or bean pod, and this type of fruiting body is called a legume, which is typical of the Fabaceae. A legume is a dry (as opposed to fleshy) fruit which dehisces (opens) along a seam, usually on two sides. Legumes come in many forms, and are long and skinny, as in the acacias, while others are shorter and stouter, like those of a lupine. Peanuts, which are not nuts at all, are legumes that develop underground - a rare trait called geocarpy.

Most Fabaceae leaves are alternate (not opposite each other on the stem) and pinnately compound (meaning there are many leaflets on the petiole, or leaf stalk). Fascinatingly, compound leaves of the Sensitive Plant (Mimosa pudica) fold inward when touched. At the base of each petiole is a stipule, or growth, that can come in the form of a thorn or a leaf-like shape as in the Garden Pea.

The three subfamilies of the Fabaceae have quite different flowers. Flowers of the Mimosoideae subfamily have enormous stamens and tiny petals often in a spherical shape - kind of like a pom-pom. Faboideae subfamily flowers are Papilionaceous, meaning butterfly-shaped - a large petal on top folds into two smaller petals, with two other small petals forming the bottom of the flower. Overall they are somewhat concave and are bilaterally symmetrical, like the human face. And finally the flowers of the Caesalpinioideae subfamily are also bilaterally symmetrical but the petals are usually all the same shape and the flower is more “open” than concave.

Plants in the Pea Family are found nearly everywhere on Earth, so there’s probably one near you! If you think you see any of these this week, share your observations with us. We’ll be keeping track here. Happy Fabaceae hunting!

Posted by loarie loarie, April 05, 2016 07:02

Comments

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Hi @loarie ,
I cannot more easily find the projects of the week.
Why? It changed some setting?
To get here to see the Critter Calendar this week I had to go searching through your projects...

Posted by scubale over 4 years ago (Flag)
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whoops thanks for noticing that @scubale - it should display on the dashboard as usual soon

Posted by loarie over 4 years ago (Flag)

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