Dwarf Tulipa - catching up

Jim McKenney jimmckenney@starpower.net
Wed, 25 Feb 2004 12:34:18 PST
In discussing Tulipa saxatilis and Tulipa bakeri Lilac Wonder, Mark
McDonough said:

>The two species are regarded as quite distinct...

And he is quite right. But regarded so by whom, and why? As garden plants
they certainly are distinct. But are they "two species"? That's where it
gets interesting. And if you read on, perhaps you will emerge with a
different opinion. A brief layperson's glossary is provided at the end to
help keep everyone up to speed in this discussion.  

The name Tulipa saxatilis was originally used for a triploid tulip.
Triploids do not form sexually reproducing populations. They cannot be true
species; there has to be more to the picture.

Tulipa cretica and Tulipa bakeri are the likely candidates for
consideration as the source of T. saxatilis. For purposes of discussion,
let's assume that it was T. bakeri. T. bakeri was named later than T.
saxatilis. That means that if T. saxatilis is regarded as a triploid form
of T. bakeri, the name for the aggregate becomes T. saxatilis. It's a case
of the rules of nomenclature requiring that the tail (triploid, nominal
species Tulipa saxatilis) wag the dog (diploid sexually reproducing species
T. bakeri).

If evidence should arise showing that T. saxatilis has some other origin,
then the entire picture changes. 

For those of you who do not have a technical background yet want to
understand what this is all about, here are some informal definitions:

diploid: with two sets of chromosomes, one from each parent
triploid: with an extra set of chromosomes. The term "sterile triploid" is
virtually a cliche, but it is an inaccurate one; triploids can and do set
viable seed under the right conditions.  

sexually reproducing populations: for purposes of this discussion, true

nominal species: species in name only, not really true species; in the bad
old days, taxonomists named everything in sight before they really knew
enough about the biology of the entity in question. Familiar examples of
nominal species are Lycoris squamigera, Lilium lancifolium, Hemerocallis
fulva and Crocus sativus.

Jim McKenney
Montgomery County, Maryland zone 7 where foliage of Tulipa saxatilis
planted in early December is just emerging. 

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