The Apogon Section 23 
a white flowered form, differing from blue forms merely in the absence of the colour 1 . The supposed 
variety trigonocarpa (see Synonymy) is based on the characters of the capsule of /. prismatua Pureh, 
with which a small form of /. sibirica was confused, while the /. triflora Balbis, which Ascherson and 
Graebner make into another variety (see Syn. pp. 506-7), is shown by its ovary to be a variety of 
/. ensata Thunb, In fact, until plants can be obtained from various localities and grown side by side 
under similar conditions of soil and climate, we can only leave unsettled the question of the existence 
of distinct local forms. 
I. sibirica has been fertilised with pollen of I. Dclavayi and the cross produced a tall sterile 
hybrid, distinguished from /. sibirica by little else than its great height (5 — 6 feet) and the slightly 
more prominent white markings on the blade of the fall. /. sibirica will also hybridise with 
/. Clarkei and the resulting plants are intermediate between the parents. 
There are also in cultivation crosses between I. sibirica and I. orientalis, providing a series of 
forms intermediate between these two species. 
For cultivation, propagation, etc., see p. 19. 
ft I. ORIENTALIS 
(Plate I by 
Thunberg in Trans. Linn. Soc. II. p. 328 (1794). non Miller. 
Somoku Zusetsu, II. 5 (unnamed). (The Japanese name is Ayame.) 
Synonyms. 
I. sibirica, Thunb. FI. Jap. p. 33 (1784). 
I. sangninea, Donn, Hort Cant ed. VI. p. 17 (1811). 
/. sibirica var. sanguinea , Ker in *Bot. Mag. t. 1604 (1813). 
/. Nertschinskia, Lodd. Bot Cab. t. 1843 (1832-3). 
I. haematophylla , Fisch. in Sweet, Brit. FI. Gdn. t. 118 (1825) non Link. 
/. sibirica var. orientalis , Baker, Hdk. I rid. p. 9 (1892). 
Xiphium orientate, Schrank, Flora VII. 2 Beibl. p. 19 (1824). 
* The fact that the white forms breed true in colour when self-fertilised tends to show that the absence of colour acts as a 
Mendelian recessive character. 
a Only the flower of /. orientalis is represented in the plate. The plant sketched behind it is /. sibirica and the sketch is 
intended to show the relative length of stem and leaves in that plant. 
