| Dykes in The Genus Iris, 1913;Description. Rootstock , a stout compact rhizome. Leaves , broad, ensiform, pale yellowish-green, the outer leaves of each tuft being often very blunt and rounded at the tip (see Fig. 24). Stem , I 2-20 in. high, bearing a crowded compact inflorescence, the lateral buds being nearly sessile, each set in a ventricose navicular bract (cf. Fig. 23). Spathe valves , very inflated and navicular, light green, membranous, hardly scarious even at the tip, 2-2¼ in. long, the outer valve being sharply keeled.*Pedicel* , very short. Ovary , rounded hexagonal, with six shallow grooves, bright green, walls very thick. Tube , about an inch long, bright green, faintly mottled with brown purple spots. Falls , obovate cuneate, of a greenish-yellow colour, veined with brown purple on the haft and sometimes also on the blade. The beard is composed of stout densely set whitish hairs, tipped with bright orange. Standards , the blade is a rounded oblong, narrowing sharply to the haft which is mottled with red-brown. The colour is the same greenish yellow as the falls. Styles , very broad, pale, semitransparent yellow, keeled. Crests , almost quadrate, with a much serrated edge. Stigma , entire, oblong. Filaments , short, colourless or very pale yellow, sometimes tinged with faint mauve. Anthers , white or very pale yellow. Pollen , cream. Capsule , 2 in. long, nearly circular in section, tapering gradually to either end. Seeds , brown, wrinkled, compressed, with a faint, small, whitish aril.Observations.This yellow Iris from the Caucasus was apparently in cultivation in the time of Lindley but was confused with Redoute's I. flavescens from which it is easily separated by its membranous, inflated, green spathes, which at the flowering time are only slightly scarious towards the tip and edge, while those of I. flavescens are not inflated and are moreover nearly wholly scarious.In certain conditions, possibly when the soil is deficient in lime, I. imbricata produces flowers in which the yellow colour is spoilt by dull, diffuse, irregular purple veins and blotches. Fig. 24 represents three leaves of one tuft of this Iris. It will be noticed that the outermost is extremely blunt, while the other two are distinctly more pointed. I. obtusifolia was so named, probably from freshly imported material in which the central pointed leaves had not had time to develop. I have raised seedlings of the original Kew plants of I. obtusifolia and am unable to separate them from plants sent to me direct from the Caucasus or from seedlings raised from seed from the same source.The distinction between I. imbricata and the yellow-flowered form of I. Alberti is somewhat difficult to determine. The plants look very different when growing side by side and yet it is hard to define the difference apart from the colour. On the whole, they may be separated by the following characters : I. imbricata is the dwarfer plant and has the outer spathe valve keeled, the lateral branches are also verv short so that the inflorescence is verv crowded (see Fig. 23). The hairs of the beard are yellow for their whole length and not bluish-white tipped with yellow as in I. Alberti. The filaments are not infrequently mauve.
| Bull. A.I.S. 57: 96., 97. Apr. 1935,Iris imbricata Lind!.Under the names of Iris sulphurea and Iris Talischii this plant has been received from the Triflis Botanic Garden and although there is some difference in the coloring of the several seedlings in each lot, there is hardly. enough to warrant even garden separation, although the seedlings in the lot labelled I. sulphurea are a very decent pale yellow color and there is little of the reddish markings on the inside of the hafts. Dykes (The Genus Iris, p. 180) mentions the fact that under some conditions the falls are often marred by "dull, diffuse, irregular purple veins and blotches." Our plants have shown no blotches but some faint veins particularly in the area about the beard. There was a marked difference in the carriage of the falls, most of which would not please the fancier of bearded iris. Dykes (ibid.) notes that this iris is difficult to distinguish from the yellow-flowered form of Iris Albertii, but of the latter plant we have no comparative material.The illustration of this species in Botanical Register XXXI, pI.35 (1845) is well drawn, but has more green coloring than any specimen seen here. The text is less valuable. The figure in Curtis Botanical Magazine Tab. No. 1 (1900) is less characteristic and the text valuable chiefly for the note concerning the introduction by the "late Lieutenant-Colonel Henry Lake Wells in the year 1895, in the province of Mazanderan, on the south of the Caspian Sea. Colonel Wells describes this province as a "lovely country, full of beautiful flowers, and amongst others I found a yellow Iris, growing beside the streams at an elevation of about seven thousand feet above sea-leveL" In a time when all the breeders of tall bearded iris are striving for tall yellows of the best types, it is hardly to be expected that anyone would be keen about this plant that fails so far in theirfloristic standards. ;