■ (SPEC) Iris fosteriana Ait. & Bak.

1887, Aitchison & Baker

Iris fosteriana Ait. & Baker (J. E. T. Aitchison and John Gilbert Baker, 1887, Transcaspia & N. W. Afghanistan); Subgenus Scorpiris, Juno; Color Class-Y3; See below:

• * References
• * Chromosome counts
• * Synonyms
• * Variations
• * Hybrids
• * Distribution and Cultivation

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References:

Aitchison & Baker in Trans. Linn. Soc. Ser. 2: 3, 114. 1887;
John Gibert Baker in Curtis's Botanical Magazine 118: tab. 7215. 1892, offers the following description "This new species of bulbous Iris belongs to the same group as I. orchioides (Bot. Mag., tab. 7111)[actually I. bucharica], and I. sindjarensis (Bot. Mag., tab. 7145)[now I. aucheri]. From a horticultural point of view it differs from all its allies in the diversity in color of the different parts of the flower. It was discovered in 1884 by Surgeon-Major Aitchison, F.R.S., whilst acting as naturalist to the Afghanistan Delimitation Commission, growing plentifully at Badghis in dry soil on the low hills at an elevation of three thousand feet above sea-level. These spring-flowering bulbous Irises of Central Asia are difficult to cultivate in our comparatively damp sunless climate, but here, as in so many other cases, Professor Foster, after whom the species was named, has surmounted the difficulty, and our drawing was made from specimens which he sent from Cambridge this present spring. Descr. Bulb oblong-cylindrical, about an inch in diameter, with brown membranous outer tunics produced above its neck and many fleshy root fibers. Leaves four to six, contemporary with the flowers, crowded, falcate, lanceolate-acuminate, firm in texture, pale green, channelled down the face, strongly ribbed and furnished with a pale thickened horny border. Peduncle very short, bearing usually one, rarely two clusters of flowers. Spathes ventricose, about two inches long; valves subscariose and pale green at the flowering time. Perianth-tube reaching to the top of the spathe or slightly exserted; outer segments bright yellow, with a spreading obovate blade streaked with black, shorter than the ascending claw; inner segments shorter, pendulous, bright lilac, obovate-unguiculate. Styles above an inch long; crests large, oblique, ovate. Anther about as long as the filament."
Krel. 1892; Grull. 1907; Van T. 1909;
Dykes, The Genus Iris, 1913; noted; Description. Rootstock, a slender bulb with persistent, "Slender, fleshy roots ; the outer coat 1s membranous, of a dark greenish-black colour.> Leaves, few in number, the longest being 8-10 in. long by f m. at the widest point, channelled, gradually tapering to a point, striated' and glaucous green on the outside. The inconspicuous white margin bears no setae. Stem , hidden by the clasping leaves, about 6~8 in. long from the ground level to the base of the spathe ; I-2-flowered. After flowering, the stem becomes 9-12 in. long. Spathe valves , narrow, very pointed, somewhat inflated, green except at the very tip, striated, 2-3 in. long, reaching above the top of the tube. Pedicel , none. Ovary , rounded, trigonal, 1/2 in. long, with thin walls and slightly convex sides. Tube ,1-1 1/2 in. long, light green, hollow for some little way down. Falls . The haft, which is poised at an angle of about 45 degrees, is 1 in. long by 3/8-1/2 in. broad, of a creamy yellow with a greenish tinge.Two conspicuous purplish veins run on either side of the central ridge. The orbicular or oval blade is about three-quarters of an inch in diameter, of a rich yellow, with a creamy white edge. On the blade the central orange ridge becomes conspicuous and denticulate. Standards , oblanceolate unguiculate, an inch long, horizontal or deflexed, of a rich red-purple colour. Styles , an inch long, of greenish yellow colour often with some purple streaks. Crests , large, 1/2 in. long, almost quadrate. Stigma , conspicuous, oblong. Filaments , cream, equal to the anthers. Anthers , cream. Pollen , white. Capsule , rounded, trigonal, with slightly convex sides; walls papery, It-2} m. long, closely resembling that of I. xiphium. Seeds , small, cubical, reddish-brown, slightly wrinkled. Observations. This species is distinguished from all others that are in cultivation by the dark olive-green coats of the slender bulb and by the contrast between the large purple standards and the yellow of the falls. In my experience I. Fosteriana is not an easy plant to cultivate. The growth is always slender and somewhat weak, with the result that the effort of flowering seems to reduce the strength of the plant to such an extent that good bulbs are not formed for the following year. Indeed, the small offsets are often so weak that they succumb altogether. It is possible, however, that this Iris would grow better in a heavier soil than that in which I have hitherto grown it, provided that the position was sheltered, warm and well drained, and that the soil was kept absolutely dry for some months in summer by some arrangement of glass overhead. After carefully comparing with my plants of I. Fosteriana a sketch of I. Narbuti drawn by Mme Fedtschenko in Sumarkand many years ago and very kindly lent me by the artist, I have failed to find any real difference between the two plants. It is true that the blade of I. Narbuti bears some dark markings near the end of the crest but these dark markings occur irregularly in other Juno I rises, e.g. in I. orchioides and I. bucharica, and I see no reason why they should not also occur in some specimens of I. Fosteriana, especially as the style branches bear in some cases a number of olive brown streaks. I. Fosteriana seems also to be peculiar in one other feature, namely in the structure of the leaves. These are much more distinctly striated or ribbed on the under surface than are those of any other Juno Iris that I have been able to examine, and moreover they bear along the ridges or ribs a number of spiny processes such as I have not found on any other species.
A Guide to Species Irises, their Identification and Cultivation, The Species Group of The British Iris Society, 1997, Cambridge;
Images courtesy of The Flower Photo Site

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Synonyms

Juno fosteriana (Aitch. & Baker) Rodion., Rod Iris-Iris: 208 (1961);

Iris caucasica var. bicolor Regel, Trudy Imp. S.-Peterburgsk. Bot. Sada 9: 620 (1886).

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Chromosome counts

2n=18 Zakharyeva & Makushenko 1969;

2n=18 Gustafsson & Wendelbo 1975.

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Variations

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Hybrids

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Distribution and Cultivation

Distribution: Region:
Cultivation: seems to be the same as most bearded irises with perhaps a special emphasis on good drainage

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-- BobPries - 2010-01-11