More leaf windows

It’s a sunny Saturday morning, and one regular chore is watering the house plants.  The sunlight was hitting a nice little Haworthia, a succulent member of the lily family (although recent phylogenetic shakeups may have changed that), and the leaf windows were pretty obvious.  They tend to look darker green, but you're really looking down through the leaf tissue.  Thick leaves are good for conserving water, but their very thickness means light penetration is limited.  Having transparent areas on the upper ends of their leaves not only allows light to penetrate deep into the leaf, but it also allows a plant like this to grow almost buried in soil.  Keep your eye out for similar features on other thick-leaved plants, you can never guess where they might appear.  And of course TPP's usual reminder; being a succulent is not the same as being a cactus.  The former is an adaptation for xeric environments that you can find in many groups of plants.  Cacti are a specific family of plants. 

Leaf windows

While easily bored, the Phactor also can easily amuse himself as long as there is some nature to play with.  And you just never know what new thing you will see ifyou look carefully enough.  So while the various cousins amused themselves with the aquatic equivalent of motorcycles, the Phactor poked around in a nearby salt marsh just to see what you could see.  The seaside ox-eye (Borrichia frutescens) is a pretty common plant in such places in our part of the world.  If you know anything at all about plants it would not surprise you to find that the leaves were thick, succulent, and waxy, common features of plants in dry or salty environments that present similar problems for plants. But did you look closer?  The lower side of the leaf when held up to the light shows this attractive veiny pattern. The lighter green pattern is produced by clear areas, windows to the leaf's interior. Such windows are pretty common in other succulents, but came as an unexpected surprise here. The plant tends to hold its leaves more or less upright, thus presenting this windowed lower surface to the outside presumably so the morning or afternoon rays of sunlight can enter through the windows illuminating the green palisade layer from the bottom side. Most of the leaf mesophyll is almost devoid of chloroplasts.  This is an educated guess; anyone know for sure?