In Pursuit of Variegated Roof Iris

  by Bob Pries

Iris tectorum alba, Pries photo

Iris tectorum (the Japanese roof Iris) is one of the easiest species to grow. Many years ago, I heard about a variegated form and got very excited. In my eyes, the white flowers of Iris tectorum are one of the most enchanting of Iris flowers. Unfortunately, this variegated form was said to have blue flowers. I imagined how stunning the white flowers could be with beautiful variegated foliage.

When I finally saw some plants of this variegated form, I was somewhat disappointed in the quality of the variegation. It was much like some of the variegated, tall-bearded irises that have irregular streaks and stripes. It was, though, much more pronounced than what you see in virus-infected plants. However, the plants themselves were not robust growers, and this clone seems to have died out in cultivation.

There was one troubling fact. The insert image of the blue flowers was not Iris tectorum. At the time, I lived in zone 6 in Missouri. The image I thought looked very much like images I had seen of Iris japonica. But japonica does not tolerate zone 5 winters well. The foliage when received appeared more glossy.

Iris japonica flowers, Hensler photo

 

About the same time that I was eagerly searching for someone who could share a piece, I saw an advertisement in a general garden catalog. It showed an image of beautifully variegated foliage and a small insert of blue flowers. It proclaimed, "Variegated Iris tectorum for sale," so of course I ordered it. But the leaves were more slender than I. tectorum and it appeared I had gained a new house plant.

Variegated Iris japonica Pries photo

In trying to find out more about variegated Iris japonica, I found references that suggested there is more than one form of variegation and at least two types grow in Japan.

The next year I visited a very large perennial nursery outside of St. Louis. The proprietor—who I knew well—was proud to show me a huge planting of variegated Iris tectorum being used as a groundcover. It was absolutely gorgeous. I felt a bit guilty when I told him it was not Iris tectorum but japonica. I warned him it would not make it through the winter but he did not dig it up and it all perished. More and more I kept seeing Iris japonica incorrectly labeled as Iris tectorum in the trade.

Iris japonica, one of three focal points. The others are Brugmansia 'Snowdrift' upper right and variegated Curcuma; Pries photo

Since moving to North Carolina (zone 7) I have grown many forms of Iris japonica. Tony Avent’s Plant Delights Nursery (zone 8) has selected several with differing flower colors. All the green leaf forms survive my winters. They are especially good as groundcovers under the dry shade of Pine trees. But I still love the variegated form which I maintain as a pot plant. It seems just a bit more tender than its green cousin. It is especially attractive as a focal point in my houseplant garden and is a feature of my deck garden of potted plants. I would be delighted to find other forms of the japonica but someday I hope to grow a true variegated tectorum.

Variegated Iris japonica repeats the angular texture of Yucca 'Colorguard' Pries photo

Alternatives to Bearded Iris at the Show

May is iris season in most places, but not only bearded iris.

Although Iris shows abound and these have everything from Intermediate to Tall Bearded Irises and an array or aril and aril bred Irises, there's so much more if you seek out variety.


The first are a couple of the crested iris species. I suppose everyone knows the 'story' of the so-called "Japanese Roof" Iris, Iris tectorum. It is not from Japan and it doesn't grow on roofs. Of course. The species is native to China where it is known simply as "Iris". It is common, wide spread, tolerates a range of growing conditions and the Japanese long ago brought plants from China to Japan where it escaped and settled down.

The story goes that in feudal Japan the Shogun and other powers mandated that only edible plants could be grown by the peasants. Although it is true that the ground rhizome of Iris tectorum is used to produce a fine quality of pale face powder, it is not true that women skirted the growing ban by cultivating this iris on Japanese thatch roofs to divert from the terrestrial restrictions. I imagine it CAN be grown in a thick thatch, but surely some wise ladies could find a spot in the corner of the rice fields or around a corner to stick a couple rhizomes of this lovely iris. What is true is that the first western botanists who 'discovered' this species fell hook line and sinker for this fairy tale.... and it does make a good story, one of those garden conversation starters.



The nice thing is that the iris is easy to grow, hardy and can be very floriferous when happy. The typical blue-violet color is remarkably consistent although a few named variants have been introduced over the years. The biggest variation is the nearly pure white 'Alba' form. Unlike many 'albas' it is equally vigorous and hardy. An added bonus is that it is easy from seed and the white form comes true. The SIGNA seed exchange almost always has seed available.



Although there really are varieties with variegated foliage, there are no named cultivars. A few different variegated patterns have been reported and at least one is occasionally offered for sale. It has white stripes in the foliage in early spring, but as summer approaches the variegation fades. It is a weak grower and poor bloomer compared to typical forms.

Iris tectorum is suited to all but the very coldest or hottest and driest gardens. It makes a good non-bearded specimen for the May Iris shows.

Quite comparable in many ways to this Asian beauty is the American native, Iris cristata , the Crested Iris. This species is native to a large part of the Central United States where it grows in thin soils in woodlands. It can form large mats of leaves dotted with flowers ranging from white, to blue to violet. Most gardeners find it fairly easy to grow in light shade and woodland soils.



The flowers are born on short 'stems' rarely more than six inches except in a cultivar such as 'Powder Blue Giant' which, as you might suppose is taller. There are more than a dozen named cultivars including all the color range plus those with double flowers. Its small size and ultra floriferous nature make it perfect for the woodland rock garden.



Iris cristata is a near perfect educational 'point' for iris shows. It is so much tinier than most other entries, it has a distinct form and it is native to the United States. If your show has an "Artisitic Design' Section for small arrangements this species has a very high 'cute quotient' and is tailor made for that.



Even smaller and a bit trickier to grow is the Lake Iris, Iris lacustris, found around the Great Lakes of the United States in gravel and sandy spots under shoreline cedars. Like its relative the crested iris, it occurs in shades of blue, violet and white although the latter is quite rare. The whole species is rare and it is protected in many parts of its range. The Lake Iris grows in similar situations to the Crested Iris, but may be even hardier. As a cut flower in the Iris show it may bewilder many of the viewers. The gardener just has to keep track of it so it doesn't get over grown by more aggressive companions in the garden.



Of course the rarest of the rare are the historical reports of pink flowered Crested and Lake Irises. Both have been rumored, but neither plants nor pictures exist. We can only dream.

Meanwhile these medium, small and smallest crested iris are perfect garden and show conversations starters. And if all you grow is bearded irises of all sorts, you need to expand your growing horizons into these woodland wonders.

9 Out Of 10 Gardeners Recommend Crests

by Jim Murrain

The best known of the Crested Iris is Iris tectorum. It is often referred to as the 'Japanese Roof Iris'. Of course we now know that it is not native to Japan nor does it grow on roofs unless forced to do so. It is one of the most common of the irises native to China. 

 It is very easily grown from seed or, thanks to its fairly large rhizomes, from divisions. Iris tectorum seeds have been available via the SIGNA (Species Iris Group of North America) Seed Exchange every year since I joined almost 25 years ago. It remains a very popular iris.

When grown from seed and a goodly number planted in your garden you can admire the many different shades of lavender and even white this iris manifests.

However we must take note of the crests! They can vary a lot on each seedling and somewhat on each fall! It can look almost like a simple beard or large jagged ridge to wild shapes that remind me of corals seen  under water. 

The amount of spotting or water marks on Iris tectorum can also be highly variable. It can have clear clean colors to heavily marked petals. The marks show predominantly on the falls but can manifest on the standards also. 

This is one Iris where you can say "I have the blue, now I want the white". But the fun of growing a number from seed is to see the natural variations that can occur.

Even after being grown world wide for many years there are only a few named selections available, and they were primarily chosen for larger flowers or the amount of spotting. None of the odd forms have been chosen. I'm sure some of you would enjoy a monstrous form as seen here:

Iris tectorum has a huge range in its native land and can be grown in most places where people live. It will need a protected location in very cold climes and may benefit from growing in a pot under shade in warmer areas to help keep it cool when dormant. It is a fun iris in so many ways, and so easy even a child can grow it.

Most of the photos were taken in the garden of Rick Davis of Independence, Missouri and grown from SIGNA seed.

'Woolong' wins 2013 Founders of SIGNA Medal

By Jim Murrain

The 2013 Founders of SIGNA Medal is awarded to...

'Woolong' collected and named by James Waddick of Missouri.

Here's a full description of this beautiful Iris via the Iris Wiki:

'Woolong' (James Waddick, R. 2001). SPEC (tectorum), height 10" (25 cm), Mid bloom season. Blue violet, falls with darker spots and flecks, white signal and crest; style arms paler blue violet. Collected in wild, Woolong Valley, Sichuan, China, 1989. Iris City 2002. HM 2006, Award of Merit 2010. 

The photos are of the original collection site and taken by James Waddick.

This is Jim's third win of this prestigious medal.

For information about this award go here.

Following is a brief description of Waddick's finding of Iris tectorum 'Woolong'.

In the summer of 1988, Jim Waddick, Bob Pries and Jim Murrain all thought that some one should go to China and collect some new wild species plants to expand the gene pool. 

It fell on Jim Waddick to go in May 1989, and then the Tiananmein freedom demonstrations started. Straying to the far reaches of the country, Jim and his guides traveled to the famed Woolong Valley of Sichuan Province, best known for its Giant Panda Reserve. 

While driving the only road through this narrow valley, Jim saw some vaguely familiar (but not quite) leaves hanging over the road, and they stopped. There was a huge patch of the crested Iris tectorum, but extending 20 or 30 feet across and looking especially big and husky.

 It all seemed to be a single giant plant connected by years of spreading rhizomes. A few fans were collected and survived in cultivation. It did prove to be an especially vigorous form of this familiar iris and was then named and introduced.

Please visit  the: Species Iris Group of North America website to learn more about growing and identifying the diverse species of Iris.

What is in a name? Lophiris - Crested Iris – Part One

By Maggie Asplet

When thinking about what I would write for this blog, it was before our main spring bloom season, just at a time when the sight of things to come was teasing us.  Many of our New Zealand iris lovers have these beautiful irises in their garden.  I am talking about the “butterfly iris” or more correctly Iris japonica and some of the different hybrids.

This iris is a native of China and Japan, a species in the genus Iris, it is also in the subgenus of Limniris and in the Lophiris section.  It is a rhizomatous perennial plant, with pale blue, lavender or white flowers with an orange or yellow crest. It is cultivated as an ornamental plant in temperate regions.

Often referred to as either a Crested Iris or an Evansia, and then there is Iris confusa. Confused, I sure am.  I quite like the term “butterfly iris” and look forward to any discussion relating to the correct naming.  This is one section of the iris world that I need to learn more about.

Iris confusa (?) in my garden

Actually, as I started my research on these irises, I was rather surprised to fine how many I have, so more research and understanding is required. 

The next one is a delightful clump of Iris confusa ‘Martyn Rix’, in my garden

Named for a UK plants man Martyn Rix, this iris gets bamboo-like stems to 2'-3' (80 – 95 cm) topped by fans of long green leaves from which the long flower stems emerge bearing a swarm of dark blue-violet flowers which are deeper coloured than typical for the species.

Another similar iris known as ‘Chengdu’, is often confused for the above iris.  Similar in size but slightly different in depth of colour.  Registered by Jean Witt in 1997, this Evansia SPEC grows to around 24” (61 cm).  Standards and style arms are light lavender, the falls slightly darker, signal white with medium lavender halo and a yellow crest.  Originally collected in 1980 by Jeanne Gardiner between Kanding, Tibet and Yaan, Sichuan, China around 3000’ elevation.

‘Chengdu’ in my garden, which was flowering in late September

Now to look at some of the hybrids created in New Zealand

Queen’s Grace, growing in my garden

Queen’s Grace is a cross between I. wattii X I. tectorum hybridized by Jean Stevens in 1955.  36" (91 cm), standards are clear lavender-blue, the falls same flecked deeper at haft; multi-ridges crest on falls, cream-white flecked brown.

We still have a number of gardens where it is blooming in New Zealand.

Question Mark

Registered in 1982 by Revie Harvey, this Evansia grown to 54-60” (137-152cm).  Smooth pale lilac, deeper toned fleck markings, bright gold crests, signal points radiate from crests, dark green foliage topping dark purple green canes.  It is of unknown parentage but probably I. wattii X Darjrrling or I. Confusa

Kilkivan

Registered by Mrs M Harvey in 1982, this Evansia grows to 54-60” (137-152 cm).  It is pale lavender with pale gold crest on white zone, numerous deep lavender signal markings, pale lavender style arms with fringed tips; deep green foliage topping medium green canes.  Parentage is an Ellis white sdlg. X Question Mark.

In Part Two we will continue to look at what I have growing in my garden, and others from around the country.

Perks of the "job"

by Jim Murrain

One of the perks of working with the SIGNA (Species Iris Group of North America) Seed Exchange is meeting people from all over the world that have a keen interest in species Iris.

I sometimes get to see newly collected and named irises like these Chinese selections of Iris tigridia in novel colors. I expect they will become available sometime in the near future.

Also these Japanese seedlings of Iris rossii. 

The first being typical while the next shows a pale blue flower,

a near white flower,

and an attempt at a double flower. 

This only hints at the untapped potential of this species.

I am also privileged to see photos of very rare and beautiful 

Chinese Iris like I. qinghainica,  

Iris collettii,

and this unusual form of Iris barbatula.

There are also many surprises like this Iris that looks like I. tectorum.

Until you see the gigantic foliage. I. tectorum on steroids?

There are also mysterious irises that appear occasionally on a photo taken 

by a tourist not aware that the Iris was unknown to the rest of the world.

This beauty was captured on film in Northeast India. 

Alas, it was not collected and only exists in the wild.

My final entry today is also a mystery. It was sold by a Chinese nursery to an avid collector in Europe as another species. But, this is Iris new to science. The perplexed owner shared it with a friend who was not satisfied with the mystery and searched for a name to no avail. I hope it will soon be named and another Iris species will grace our gardens.

Fortunately it is self fertile and has set several pods this year. 

My fingers are crossed that we will all get to enjoy this new Iris very soon.

Those Puzzling Iris Names

By Griff Crump

Some time ago  --  a few years, actually  --  the question arose on iris@hort.net as to why the various species of iris are named as they are. A whole list of puzzlers had been submitted. 

I. tectorum

While most irisarians have heard that I.tectorum means “iris of roofs” or “roof iris”, stemming from the Japanese practice of growing them on their roofs (although I have seen that explanation disputed), the meanings of other names remained obscure. Being the compulsively helpful person that I am, I offered the following explanations for some of them, which I repeat here for those who are not iris@hort.net veterans:

attica -- similar to tectorum, but grows beneath the roof

subbiflora -- same as attica, but two floors down

mandschurica -- a variety, candidans mandschurica, will sit quietly in your

garden for years, then suddenly burst into bloom

acutiloba -- smelling this one can give you a very bad case of iloba

barnumae -- a real circus of color

bismarkiana  --  though plantings may be dispersed, this one will

consolidate and take over your garden

gatesii --  to be planted at the entrance to your garden, of course

hookeriana  --  (ahem, well . . .)

wattii -- in sufficient quantity, this becomes known as voltii

minutoaurea  -- a little bull goes a long way

odaesanensis -- comes from Odessa, but ran into a spelling problem

bulleyana -- crowds out other flowers

innominata -- Linnaeus lost the tag; very common; most of us have some

nelsonii  -- British; has only one branch

crocea -- Kasparek reject, who, looking at it, said "That's a croc."

ludwigii -- first cousin to hartwegii

foetidissima -- a real stinker

bungei -- you can't get rid of this one; it just keeps coming back

farreri -- Italian, misspelled

lazica  --  has to be staked

aitchisonii -- named after the well-known railroad town  (Aitchison, Topeka

and the Sa-anta Fe)

hartwegii -- first cousin to ludwigii

galactica -- honoring the Battlestar of the same name

stenophylla -- a nice present for your secretary

stocksii -- you buy this one when bondsii is too pricey

zaprjagajewii -- named for its discoverer, a Cossack who fell into a clump

of it when his horse missed a steppe

No doubt others among us have explanations for some of the rest.  


You can see the names of all the species irises and many beautiful photos of them at the Species Iris Group of North America (SIGNA) website.


Editor's Note:  Griff invites you to add your own "definitions" for iris species names in the comments section.  Be sure to keep it clean and, above all, funny!

What is in a name? Lophiris - Crested Iris – Part Two

By Maggie Asplet

Finally, I have time to complete the second part of this article relating to crested irises.  Holidays and ill health sometimes get in our way.  I think you will all be the same when I say “it is life’.

To recap in part one we looked at I confusa, Martyn Rix, Chengdu, Queen’s Grace, Question Mark, and Kilkivan.

Today we will continue looking at some of these bigger forms of the crested iris, starting with I. wattii, with tall, tapering and sword like leaves which are heavily ribbed.  It has deep lavender spots like those of I. japonica outlining the haft.  This iris was discovered in 1892 by John Gilbert Baker, in the Himalayas & China area.

I must confess that this iris I don’t have growing at home, as I seem to have a great habit of killing it off.

Photos courtesy of Roger Haworth

Iris ‘Bourne Graceful’ 

Bourne Graceful has a medium size flower which is deep lilac-blue with strong orange-yellow signal surrounded by old gold to dark violet flecks and a violet border around the white signal area. The flowers are borne on distinctive green stems that become darker towards the bottom, but the plant itself has no canes. The long glossy leaves are ribbed and coloured purple at the base.

Registered by Dr J R Ellis in 1975.  It stands tall at 42’ (107cm) and classed an early to mid season for flowering.  I. japonica var. Ledgers X I. japonica var.

Photo courtesy of Huib Selderbeek

Iris ‘Nada’

J.N. Giridlian of California hybridized I. confuse and I. japonica in 1936. The plant grows about 18 “ (45 cm) tall and the flower spike can reach to about 24’ (60 cm)  Although each flower only lasts about two days, the entire spike will remain in bloom for over a month as new flowers open to replace spent blooms. It is very floriferous and each spike will produce about 25-50 flowers.  

I am pleased to say this one I can grow quite successfully and I think it has the sweetest little flowers.

Iris 'Nobody’s Child'

This is the first of three lovely iris hybridised in New Zealand.  In 1993 Isobel Simpson registered iris as SPEC (evansia), growing to 11" (28 cm).  The standards are light lavender blue, edged paler; the falls are pale lavender blue, royal blue at end of crest, olive brown to deep blue spots; sweet-musky fragrance.  Parentage unknown.

Photo courtesy of Huib Selderbeek

Iris ‘Honiana’

Hybridised by Mrs. F. Love in 1984, growing to 22" (56 cm).  Described as mauve with khaki brown markings on falls, white crests, with a sweet fragrance.  This is a cross between Question Mark X I. tectorum.

Photo courtesy of Huib Selderbeek

Iris ‘Revie’s Legacy’

A fairly recent registration (Joy Turner by Ron Goudswaard) in 2010.  Taller than the previous two growing to 59" (150 cm) and is classed early flowering.

The standards are pale lavender-blue, darker edges, near white center; style arms pale lavender; falls are white edged lavender-blue, white overlaid with ochre brown dashes radiating out from crest changing to dark blue dots and blotches toward edge of white area; appears plicata pattern.

It is probably a cross between Question Mark x I. tectorum.

Photo courtesy of Huib Selderbeek

I have not covered any of the smaller iris that belong in this section.  This I will leave for another day.  It won’t be long before we start to see the beautiful flowers of these again as we are heading towards winter (fall) here.