92 
The Apogon Section 
Colorado. Estes Park, 1884, Ball (K). 
Marshall Pass, 1901, Baker (K) (B) (E). 
Custer Co., 1891, Cusack (K). 
Platte Canon, 1894, Henry (E). 
Arizona. Flagstaff, 1 88-, Hughes (Hort Foster in MS.). 
Cave Dwellers' Gulch near Flagstaff, 1889, Munson and Hopkins (W). 
Diagnosis. 
I. Montana imberbis ; /. missouriensi proxima sed caulis foliis adultis brevior ; spathae biflorae nec 
multiflorae ; segment a interiora oblanceolata nec obtusa nec emarginata. 
Description. 
Rootstock, a short-creeping rhizome, clothed in stiff dark brown sheathes. 
Leaves , firm, narrowly ensiform, about 12 — 18 in. by ^ in., of a glaucous green. 
Stem, 18 — 20 in., naked. 
Spathe valves, 2 — 4 in., scarious in upper part, narrow, sharply keeled, usually 2-flowered ; although 
a third flower is rarely produced. 
Pedicel, 1 — in. 
Ovary, £ in., sharply trigonal, with concave sides. 
Tube, g in. long, purple, first constricted above the ovary and then expanding. 
Falls, narrowly obovate cuneate, with low rounded median ridge ; on either side of this the ground 
colour is yellow, especially beneath the ends of the styles. The blade is covered with diffuse lavender 
veins, on a faint lavender ground. The shade of lavender may be light or dark. 
Standards, oblanceolate unguiculate, slightly shorter than the falls, lavender, not blunt nor 
emarginate as in I. long ipe tala and /. Montana. 
Styles, small, narrow. 
Crests, narrow, subquadrate, coarsely toothed. 
Stigma, entire, oblong. 
Filaments, shorter than anthers, pale violet. 
Anthers, purple. 
Pollen, cream. 
Capsule, rounded trigonal, tapering gradually to either end. 
Seeds, pyriform, with smooth brown coats. 
Observations. See the introduction to the longipetala group. 
XIV. The Tripelalous group. 
It is, of course, an exaggeration to say that the two species that form this group have only three 
perianth segments. The three inner segments are also present, but in a greatly reduced form. Indeed, 
it is not always easy to detect the small bristle-like projections to which the standards are reduced. 
This phenomenon is only known to occur in one other Iris, and that is I. Danfordiae, a bulbous species. 
The species may be distinguished as follows : — 
Leaves ensiform ; spathes sometimes partly scarious in the upper part, flimsy ; capsule I. setosa (p. 92). 
trigonal ; seeds oval, rounded with a conspicuous raphe running down one side, 
see Plate XLVIII, Fig. 15. 
Leaves linear ; spathes wholly green at flowering time ; rigid ; capsule rounded ; seeds I. tripetala (p. 94). 
compressed, disc-shaped. 
t + /. SETOSA 
Pallas ex Link, Jahrb. I. iii. p. 71 (1820). 
Ledebour, FI. Ross. IV. p. 96 (1853). 
•Regel, Gartenflora, t. 322 (i 860 . 
•Trans. Russ. Hort Soc. 1861, p. 196, t. 48. 
Baker in J. L. S. XVI. p. 140 (1877). 
Hdk. I rid. p. 11 (1892). 
•Somoku Zusetsu, Vol. II. p. 8 (Jap. Hi-ogi-ayame, fide Dr Takeda). 
Synonyms. 
•/. brachyaispis, Fischer ex Sims, Bot. Mag. t. 2326 (1822). 
Xipliton brachycuspis, Alef. BZ. XXI. p. 297 (1863). 
Xyridion setosum, Klatt, BZ. XXX. p. 500 (1872). 
I. brevicuspis, Fischer ex Sims, Bot. Mag. 2326 (1822). 
/. Hookeri, Penny in Steud. Nomencl. ed. II. p. 822 (1840). 
•/. tripetala, Hooker, Bot. Mag. t. 2386 (1829) non Walt (cf. S. Watson in Bot. Gaz. XII. p. 99 (1887)). 
/. arctica, *Eastwood in Coult. Bot. Gaz. XXXIII. p. 132, Fig. 2 (1902) [Specimen (K)]. 
I. yedoensis, Franch. et Savat Enum. PI. Jap. II. p. 522 (Yedo 1871, Savatier no. 1223 (P)). 
