how many differences for a species?

Mary Sue Ittner
Sun, 22 Oct 2006 11:16:44 PDT
Dear Diane,

After trying to identify plants in the wild in South Africa and looking at 
minute differences in the keys (stamens slightly exserted versus well 
exserted, filaments a tad longer, etc.) I started wishing some of the look 
alikes would be lumped together. Manning and Goldblatt seem to be 
eliminating a lot of subspecies classifications and I'd suspect that as you 
see the variations in the wild as they do since they go out a lot that it 
is simpler not to have a subspecies for each difference. One wonders if in 
some situations new species become new species so the person who names them 
can have their name attached to more things. I don't know who determines 
what you need to have a new species. Hopefully someone will respond with that.

There are Lachenalias that are very difficult to distinguish and I already 
wrote about my struggles with white Ornithogalums. White Geissorhizas and 
white Hesperanthas are also a challenge. Having said that, with the South 
African irids it appears there are sometimes significant differences in 
corms and that can be the distinguishing difference which doesn't help much 
unless you dig it up to look. Still that's better than some of California's 
Alliums that you tell apart by looking at the bulb coat (if it is still 
there) under a microscope so you can see the patterns. Putting pictures of 
the organs on the wiki could be helpful to us all I think. I believe Audrey 
Cain who grows so many South African bulbs is photographing the organs and 
may even be putting them on her web site and hopefully will be sharing them 
with us for the wiki too. I've added some as I've had time. With Romuleas 
there is often a big difference. You may recall we dug up a Romulea 
tortuosa in Middelpos just to be sure that was what it was (and then wet it 
and the roots and put it back.) When Scilla was being split into multiple 
new genera in the last few years (and I don't know if anyone is following 
the new names except I do see Scilla natalensis being referred to as 
Merwilla these days) it seemed like the seed pods weighed heavily as a 
determining factor. So in that case you'd have to wait until your plants 
set seed to be sure. DNA is foremost to others. Maybe some day we'll have a 
DNA gun we can aim at a plant and get a name.

As for white Hesperanthas I reported in the past that I was growing I think 
maybe four at least different ones from seed that all looked alike to me 
when they bloomed even though the name on the seed packet was different. 
The corms all looked alike too. Graham Duncan was speaking in the Bay Area 
so I took representative samples to him of each to see if he could help me. 
I thought they all might be H. cucullata. He seemed astounded at my 
request. On the other hand Rachel showed them to John Manning and he 
confirmed they were all H. cucullata. At least one of them was supposed to 
be H. falcata. All of the pictures I could find showed similar flowers of 
H. falcata and H. cucullata. H. falcata was supposed to be a smaller plant, 
but you can't tell that from a picture. The Color Encyclopedia continues to 
be a help (sometimes) with these situations since there is a key in the 
back. Once again it is lessened by leaving out winter rainfall areas 
considered north of the Cape. It says that H. pilosa has a scale-like leaf 
below the spike 3-5(-10) mm. long so if your plants are both white perhaps 
that would help.

Mary Sue

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