29 
The Apogon Section 
+*/. Clarke i 
(Plate V) 
Baker, Hdk. Irid. p. 25 (1892). 
in Hook. f. FI. Brit. Ind. vol. VI. p. 275 (1892). 
Dykes in Gard. Chron. XLVI. p. 15 (1909). 
•Bot. Mag. t. 8323 (1910). 
Synonym. 
1. himalaica , Dykes in Gard. Chron. XLV. pp. 3, 36 (1909). 
Distribution. I . Clarkei is apparently confined to a circumscribed area in the Sikkim and Bhutan region at 
a height of from 6000 to 1 1 ,000 feet. 
Tonglo (near Darjeeling), 1857, Thomson (K). 
1875, Clarke (K). 
1907, Cave (HortD). 
Sikkim (Darjeeling), 1855, Schlagintweit (nos. 12,325, 12,389, 12,634) (B). 
(Nijan), 1888, Dr King’s collector (B). 
Chumbi, 1879, Dungboo (B). 
1884, Dungboo (K) (BM). 
1904, Walsh (K). 
Diagnosis. 
I. Clarkei Apogon ; 1. sibiricae haud dissimilis sed folia supra nitida, infra glauca ; caulis solidus, 
plerumque ramosus ; spatharum valvae omnino herbaceae, virides. 
Description. 
Rootstock , a wide spreading, somewhat slender rhizome, clothed in the fibrous remains of old leaves. 
Leaves , linear-ensiform, about 2 feet long by £ — | in. wide, the upper third drooping ; the upper 
surface is polished and shiny, the under side glaucescent. 
Stem , about 2 feet long, solid, with one or two lateral heads and bearing about three reduced 
leaves. 
Spathes, 2-flowered, 2^ — 3 in. long with lanceolate, persistently green valves. 
Pedicel , 1^ — 2 in. long, triangular in section, increasing in length later to 3 in. 
Ovary , 1 in. sharply trigonal, sides slightly concave with a central rib on each face. 
Tube, £ in., much more rounded than the ovary, many ribbed. 
Falls , with conspicuous, whitish buttresses at the base of the haft, which is half as long as the 
obovate, emarginate blade. The upper part of the haft is slightly marked with yellow. The blade 
is of a blue purple colour marked and blotched with white, and reflexes laterally. 
Standards, lanceolate with a canaliculate haft, reddish-purple, poised almost horizontally. 
Styles, very conspicuous and forming the highest point of the flower. in. long, keeled, very 
convex, much curved down, so that the stigma is considerably lower than the centre of the style. 
Crests , obtuse, overlapping with irregularly indented edge. 
Stigma, rounded triangular. 
Filaments , white, edged and mottled red purple. 
Anthers , pale mauvish white, shorter than the filaments. 
Pollen, white. 
Capsule, 2 in. long, sharply trigonal with flat sides, each having a prominent median rib. 
Seeds, compressed, thin discs, lying in a single row in each loculus. 
Observations. 
This curiously local species was first discovered by Sir J. D. Hooker on Tonglo in 1848 and 
sketched by him on the spot. This sketch is now in the Kew Collection and though unfinished 
gives sufficient detail to enable us to identify the plant. It bears the words “no crest or beard," 
written somewhat indistinctly and faintly in pencil and, by a curious mistake, Baker, when describing 
the species from J. B. Clarke’s specimens, gave it both crest and beard and consequently placed 
it among his Pseudevansia group. 
When the plants flowered that I obtained from Tonglo through the kindness of Mr G. H. Cave 
of the Lloyd Botanic Garden at Darjeeling, they could not be brought under Baker’s description 
of /. Clarkei owing to the absence of beard and crest and it was only after I had described them 
under the name of /. himalaica (cf. Gard. Chron. I.c.) that Dr Stapf pointed out to me the origin 
of Baker’s mistake. 
1. Clarkei is obviously a member of the sibirica group but differs from all the other species 
of that group, except /. prismatica, in the possession of a solid, as opposed to a hollow, stem. In 
all other respects, it seems perhaps most closely related to the Western Chinese members of the 
group, /. Forrestii and /. Dulleyana, with which it agrees in having leaves, which are glaucous on 
the under side but polished and glossy above. 
The colour of the flowers borne by this Iris varies greatly even in the wild state as was proved 
by a second series of plants that I owe to the kindness of Mr Cave. All shades of blue and 
purple may occur and one of the most pleasing perhaps is that depicted in Plate V. 
