180 
The Pogoniris Section 
Distribution. Transcaucasia and North Persia. 
Caucasus, 18 — , K. Koch (B). 
1909 (HortD). 
Mazanderan, 18 — , Wells (HortD from Kew). 
Diagnosis. 
I. imbricata Pogoniris; folia luteo-viridia, glaucescentia, primigenia nonnunquam obtusa ; caulis 
ramosus foliis subaequalis sesquipedalis ; spathae membranaceae, inflatae, apice 
tantum et margine subscariosae, valva exteriore acute carinata ; segmenia omnia 
pallide lutea ; capsula rotundata. 
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, 1 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 — 2% 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 com- 
posed of stout densely set whitish hairs, tipped with bright orange. 
Stajidards, 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 Redout'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, /. im- 
bricata 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. /. obtusifo/ia 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 /. 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 
/. 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 : — /. imbricata is the dwarfer plant and has the outer spathe 
valve keeled. The lateral branches are also very short so that the inflorescence is very crowded 
Fig. 23. Inflorescence of I. im- 
bricata. About one-third or a 
quarter the natural size. 
Fig. 24. Three leaves taken 
from the same tuft of I. im- 
bricata ; the bluntest is the 
earliest and outermost. About 
half the natural size. 
