Texas Gardening: Gardening with Texas Native plants & Wildflowers. Part 7, 1 by bettydee

bettydee wrote:
I found a total of Ruellia purple,pink or white flowered species native to Texas. http://images.google.com/imgres?imgurl=http://plants.usda.go...

The flowers in all of them are very similar. The leaves vary. (I did find out that "Katie" is a dwarf variety of R. britoniana). This points to a very genetically rich genus.

So there is the possibility that you may be dealing with more than one species. Even within a species, there are many plants that exhibit variations in leaf size and shape. An East Texas native comes to mind: the Sassafras, Sassafras albidum. The leaf shape can vary, but 3 distinct leaf shapes are most common, often on the same tree. Other plants are greatly influenced by growing conditions. You don't suddenly get a genetically different plant growing from the old roots. Growing conditions had to have changed for that plant. There is also the possibility that a seedling of a hybrid grew out between the old twigs.

Some plants hybridize naturally out in the wild. Two Texas natives, the Texas Live Oak, Quercus fusiformis, and the Virginia Live Oak, Quercus virginiana hibridize easily and as you travel from the coast, through Central Texas and into the Hill Country you can see the variations caused by hybridization. Names are an issue among botanists over naming live oaks. Some lump all live oaks under one name, Quercus virginiana. Others make the Texas Live Oak a subspecies. While still others give the tree its own species name.

I can think fo 2 examples of plants greatly influenced by their growing conditions:
The Quihoui Privet, Ligustrum quihoui. I posted photos in Part 5 on June 8th. The first photo shows the shrub in partial shade. The next 4 photos show flowers from that shrub. The panicles (bunch of flower clusters) are very compact and dense. You can see the leaves clearly in the flower photos. The last 3 photos ( last one past several other postings) show another Quihoui Privet shrub growing about 50 feet from the first, but growing out in full sunlight. The panicles are longer and not as dense. The leaves have a slightly gray hue and fold up in half along the mid-vein. At first, I thought these were 2 distinctly different shrubs — very similar but different.
http://davesgarden.com/forums/t/518448/

The Water Primrose, Ludwigia peploides. This one I haven't posted yet. Plants growing out of the water have narrower and thinner leaves edged in red. There aren't as many leaves on the plant. The stems have a reddish tinge as well. The whole plant grows closer to the ground. The primroses growing in the water have wide bright green lusher-looking leaves. Everything about the plant is greener looking. The leaves are also slightly thicker. This is the photo of it growing out of the water.