82 
The Apogon Section 
t I . HEXAGON A 
Walt. FI. Carol, p. 66 (1788). 
Chapman, FI. South. U.S. p. 472 (i860), ed. III. p. 500 (1897). 
Baker in J. L. S. XVI. p. 141 (1877). 
•in Bot. Mag. t. 6787 (1884). 
Synonyms. 
/. virginica, Michaux, FI. Bor. Amer. 1. p. 22 (1803), non Linn. 
Pursh, FI. Amer. Sept 1. p. 29 (1814) ex parte. 
[?]/. Carolina, ‘Radius, Schriften der Naturiorsch. Gesell. Leipzig, 1. p. 158, t. 3 (1822). 
Distribution. The South Eastern United States. 
(N.B. In some cases it is extremely difficult, if not impossible, to separate herbarium specimens of 
/. hexagona from those of I, foliosa). 
Florida. Tampa; Hillsborough Bay, 18 — , Curtiss, no. 2852 (BM) (B) (K). 
Seville; Cypress Swamp, 1901, Curtiss, no. 6754 (E). 
St Augustine, 1848, Rugel (BM). 
Louisiana. New Orleans, 1832, Drummond (no. 336) (K) (BM) (E) (V). 
(N.B. Drummond’s no. 337 is I. fulva.) 
New Orleans, 1844, Salte (BM). 
1832, Torrey (E). 
1847, Bromfield (K). 
Diagnosis. 
/. hexagona Apogon; folia ensiformia, viridia ; caulis foliosus, floribus in axillis insitis ; segmenta 
interiora exterioribus multo angustiora, oblanceolata ; capsula trigona, angulis profunde sulco bifidis ut 
fere hexagona. 
Description. 
Rootstock, a stout greenish rhizome, somewhat resembling that of I. fulva , very wide creeping, 
often 1 — 2 ft. in length. 
Leaves, ensiform, slightly glaucous, 1 in. broad by 2 — 3 ft. long, remaining more or less green 
throughout the winter. 
Stem, 3 feet or more in height, bearing 3 — 4 heads of flowers, each branch being wrapped in a 
long, sheathing, bractlike leaf. 
Spathes, 2 — 3 flowered ; one outer valve of the terminal cluster is bractlike, 6 — 8 in. in length, 
the other being narrow, pointed, green, closely clasping the tube, 4 in. in length ; the inner valves are 
membranous. 
Pedicel, about one inch. 
Ovary, trigonal with concave sides, with a groove running down each angle. 
Tube, with many grooves, 1 — 1£ in. long. 
Falls. The greenish haft is separated by a constriction from the obovate blade, and bears a well- 
marked central ridge. This ridge is greenish at the base, but becomes yellow as it approaches the 
blade, and is covered with a distinct pubescence, which extends on either side of the ridge. The blade 
is of a pale or dark lilac (or even white), 4 — 4^ in. long by nearly 2 in. in width. 
Standards, erect, oblanceolate ; the haft is veined with green, and the blade is either lilac (or 
white). 3^ in. long by £ in. broad. 
Styles, narrower than the haft of the fall, very convex laterally, greenish, with a central well- 
marked reddish lilac ridge. 
Crests, lilac, triangular, with coarsely serrated edge. 
Stigma, bifid, with two triangular teeth. 
Filaments, £reen, very short. 
Anthers, greenish, the pollen sacs narrow, three times as long as the filament. 
Pollen , grains rounded oval, with a fissure down one side. 
Capsule, with six ribs, somewhat resembling that of I. spuria, but with the six ribs set almost at 
equal distances, and not in pairs at the angles. 
Seeds, very large, more or less D-shaped, with a thick spongy covering to the seed proper, closely 
resembling that of I. fulva (see Plate XLVIII, Fig. 3). 
Observations. 
This fine Iris and the next, I. foliosa, are obviously closely allied, and it would scarcely be 
surprising to find that they proved to be merely different combinations of certain Mendelian pairs of 
characters. Here in England we labour under a disadvantage with regard to the solution of this 
question, for, as far as I know, a certain sheltered corner in a bay between the greenhouses in the 
Cambridge Botanic Garden is the only place where the tall form that is commonly known as /. hexagona 
has flowered out of doors in England. Moreover, I. foliosa, though it flowers with me every year, 
