Antennaria@aol.com Antennaria@aol.com
Tue, 27 May 2003 20:29:30 PDT
Comments on several respondents offerings on this topic:

> Mark:
> Try these.  Looks can be deceiving.
> Alan

Thanks Alan,
I shall give these a lookup sometime.  Until such time that I get a chance, 
can you summarize, is Muilla now in the Themidaceae?  If it is, it's ironic 
n'est pa?

Mar Sue, thanks for the paragraph summarizing the differences between 
Alliaceae and Themidaceae.  Some comments:

>Alliaceae have a true bulb (composed of 
>swollen leaf bases) with a membranous 
>coat, but the storage organ in 
>Themidaceae is a corm (composed 
>of stem tissue.) 

This is a gross generalization.  Many alliums do not have a recognizeable 
bulb whatsoever
.  many Chinese species, such as A. wallichii, have nothing more that a 
ever-so-slightly thickened leaf base, and some fleshy white roots, nothing that 
you'd remotely call a bulb, but indeed merely a rhizome, and even questionably at 
that.  A large number of species do not have membranous bulb coats... some 
do, some have fibrous bulbs coats, some have no recognizeable bulb coats 

I do agree that Trits and Brodes have corms, but some Geranium species, as 
well as some Pelergoniums, have bulbs or bulb-like storage structures whereas 
most are fibrous rooted perennials.  Are they removed into their own genus?  
Alliums can have true bulbs, rhizomes (whole sections named after this feature), 
or a combination of vestigial bulb and rhizome.  Should the different groups 
be separated into their own genera?  Many genera exhibit similar rootstalk 
diversity, such as Corydalis... should these be separated out into their own 

>Most, if not all, Themidaceae lack the onion odor."
Some major sections of the genus Allium also lack the characteristic onion 
odor.  Should these non-alliaceous-scented alliums be split off into their own 
genus, or a new family perhaps.

>While Alliaceae have a pair of bracts that 
>encloses the flower buds, Themidaceae have 
>several bracts that do not enclose the young 

Alliums have *one* to *many* bracts that enclose the flower buds, not always 
a pair as described above.  The number of spathe or bract segments, and 
whether the segments are persistent or not, play a role in species determination.  
In some species the spathe is so short and ephemeral (dropping off) that the 
buds can appear as not being enclosed. The genus Muilla is described as having 
buds enclosed in several spathe segments.  What am I missing?

Alan writes:
>No South American Themidaceae.  Strictly 
>Southwestern and Western U.S. andMexican.  
>There is no true Brodiaea in Chile.  All the Chilean 
>onions are still onions.

Way back when, many S. American plants now known as Tristagma, Ipheion, 
Nothoscordum, and others, were listed as Brodiaeas, even a few as Allium.  Alan is 
quite right, there are no true Brodiaea in Chile and these genera names were 
misapplied.  When it is said "all Chilean onions are still onions", I assume 
what is meant by that is that all Chilean Alliaceae are still Alliaceae, because 
there are no true onions (Alliums) in South America.

But this Themidaceae separation has me wondering... was the division largely 
devised based on Western American and Mexican taxa... if so, therein lies the 
conventional flaw in not looking "big picture".  Most American Allium fall 
into a single type with bulbs. Consider the genus Allium in it's holistic sense, 
including Chinese Allium, the "rhiziridium" section of Allium, the 
stoloniferous Alliums, alliums with varying bract structure, rootstalk structure, even 
onion smell, and tell me that Themidaceae is justified.  I just want to be 
convinced.  I'm not adverse to sensible change, but this one really has me 

Mark McDonough        Pepperell, Massachusetts, United States  
antennaria@aol.com    "New England"               USDA Zone 5
>> web site under construction - http://www.plantbuzz.com/ <<
     alliums, bulbs, penstemons, hardy hibiscus, western 
            american alpines, iris, plants of all types!

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