Iris - exposed - Part 2 Bulbous

James Waddick
Thu, 11 Mar 2004 07:00:56 PST
>When you said the "Dutch" type of Iris was a more complex variety, 
>what did you mean.

Dear Lee et al;
	Not quite what I meant to suggest, so let me back up a bit.

1) The genus has 6 subgenera. 3 are bulbous and can be identified 
easily by bulb, foliage and flower. All of these bulbous subgenera 
have been proposed as separate genera so all names are given below. 
General guide below:

	A)	Subgenus Scorpiris (Genus Scorpiris/ Juno) The 
distinctive features of Junos are the smooth bulbs with a thin to 
leathery tunic and  few thick storage roots, leaves channeled and 
distichous(two ranked). The larger Junos like I magnifica look sort 
of like a small corn plant. Standards very reduced, usually. Size 
variable.  60 or so species.

	B)	Subgenus Hermodactyloides (Genus Iridodictyum) The 
reticulata irises have a distinctive reticulate bulb covering, leaves 
square or round in cross section, dwarf stature, flowers mostly 
typical iris form. 10-12 species

	C)	Subgenus Xiphium (Genus Xiphium) These consist of 
bulbs with a thin papery tunic, leaves distichous and channeled, but 
usually long thin and grassy. Size 12-18 inches. Typical iris 
flowers. 6 or 7 species.

2) Xiphium Iris includes Duth, Spanish, English Iris which are 
horticultural group names and other, botanical species. The species 
are rarely grown, more difficult to obtain. All are native to the 
Iberian peninsula and W. Europe - Mediterranean including north 

	a-	English Iris are selection of I (X) latifolia native 
to the Spanish-French  Pyrenees. Also known as I xiphioides. Prefers 
damp sites. Numerous named cvs.

	b-	Spanish Iris are selections of I (X) xiphium (or X 
vulgare) and native to a wide area of Iberian Pen, N. Africa to S. 
Italy. Numerous named cvs.

	c-	Dutch Iris is a group name for hybrids involving the 
above two species and cvs and at least one other species , I. 
tingitana from N. Africa. These hybrids have the widest range of 
colors and adaptability and are the ones widely grown as cut flowers. 
Collectively known as I x hollandica. Other species may be involved 
too and it is easily forced for year round bloom/sale.

3) Cultivation. My opinion only is that because they are seen and so 
well known from the ubiquitous cut flower Dutch iris ( Wedgewood' is 
THE Blue one), many people think they must be easy. This does not 
seem to be the case. Here (Zone 5) all are tender to very tender. I 
know of one garden where a few in a protected site persist and bloom- 
at least last I saw them. Generally they are suited to milder 
climates and Mediterranean conditions should suit most, but their 
needs are quite variable.
	I believe we had a discussion in the last year or so 
remarking on their difficulty in many parts of the US and weedy ease 
in others.

4)	Odds and ends; Some of these in the trade are very prone to 
virus, but like virused tulips are often quite attractive.
	Bulbous iris are not under the wing of the AIS so tend to get 
left out of most of their information -one major exception is SIGNA. 
Registration is handled by the Royal Dutch Bulb Assoc.
	There is no Bulbous Iris Society to promote or educate further.
	Basic info in BIS 'A Guide to Species Iris' 1997 Cambridge U. P.
	Although Dutch hybrids are easy to locate and cheap, almost 
all overs are less common and pricier. True species very difficult to 

	Good luck, but you have a green enough thumb to have success, I'd bet.

		Jim W.

Dr. James W. Waddick
8871 NW Brostrom Rd.
Kansas City Missouri 64152-2711
Ph.    816-746-1949
E-fax  419-781-8594

Zone 5 Record low -23F
	Summer 100F +

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