Iris - exposed - Part 2 Bulbous
James Waddick (Thu, 11 Mar 2004 07:00:56 PST)

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
Africa.

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
obtain.

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
USA
Ph. 816-746-1949
E-fax 419-781-8594

Zone 5 Record low -23F
Summer 100F +