Re: shrub ID

barbara sargent wrote:

There's a ubiquitous shrub, that seems like a weed, that I'd like to
ID. It > has a leaf around 4 1/4 inches long, tapered, around 5/8 inch at it's
widest. Then there are other leaves (are they the babies that turn into
what I described) that strongly resemble acacia leaves; they are in
twos on > a very narrow stem, folded down the center and made of tiny
oval > overlapping segments. Maybe they open at some point but I've only seen them
folded.

So, what is this shrub/tree? I believe they can grow to at least six
feet > and I've never seen a flower or seed on them but they do seem to self seed
all over the place.
Hi Barbara
The plant you are describing is I am sure a species of Acacia. Many species of this genus only show typical pinnate compound leaves in the juvernile foliage and as they grow abandon this habit for the narrow strap-shaped organs you describe, which in spite of their appearence are not true leaves, but rather modified petioles (leafstalks) which take their place and are known as phyllodes..I have once or twice seen a tree of this kind at the transition stage with some phyllodes topped with a short length of feathery true leaf.

This is a modification which cuts down transpiration (the phyllodes have no stomata) and is a water-saving adaptation typical of the interesting plant strategies found in drought-prone Australia..

There are a number of species with similar strap-shaped phyllodes and these are not really sufficiently distinct to identify the species without some idea of the final dimensions of the plant and a description of the flowers.

if you are not seeing flowers, but there appear to be new seedlings coming it seems likely to me there was a parent tree/shrub in the area in the past which _did_ flower and set seed, some of which is lying in the ground dormant and germinating a few at a time. This is very commn among legumes, which most commonly produce a proportion of their seeds each season with very hard impenetrable coats that take several years to admit water and grow. it is a very effective means of survival, as such seeds have been known to germinate after a very long time, such as more than 100 years on an herbarium sheet.

Many species of Acacia can be attractive garden plants and it might be worth while adopting one and seeing how it develops.

Moira

--
Tony & Moira Ryan,
Wainuiomata, North Island, NZ. Pictures of our garden at:-
http://mywebpages.comcast.net/cherie1/Garden/TonyandMoira/index.htm

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