31 
The Apogon Section 
+ i/. PR IS. VATIC A 
(Plate VII) 
(No explanation of the name is given.) 
Pursh, FI. Amer. Sept I. p. 30 (1814). 
•Ker in Bot. Mag. 1504 (1813) quotes Pursh's MS. description. 
•Barton, FI. III. 85 (1823). 
Roem. and Schult, Syst. Veg. I. p. 476 (1817). 
Baker, J. L. S. XVI. 138 (1877). 
Hdk. Irid. 8 (1892). 
Lynch, Book of the Iris, p. 73 (1904). 
Synonyms. 
I. gracilis, Bigelow, FI. Boston, p. 12 (1814). 
Specimen in Hb. BM. 
/. virginica. A, Gray, Bot. North. U.S. p. 482 (1848) non Linn. 
Specimen in Hb. BM. 
Chapman, Flora South. States, p. 473, ed. III. p. 500. 
I. boltoniana, Roem. and Schult, Sys. Veg. I. Suppl. 308 (60) (1822). 
/. trigouocarpa , Br. and Bouch«J, Ind. Sem. Hort. Berol. (1853) 17 ex parte. 
[Specimens of I. trigouocarpa in Hb.B. are confused with I. sibirica , both the species occurring 
together unseparated on the same sheet. The original description of I. trigouocarpa aptly 
describes I. prismatica , with which indeed it is said to agree in the structure of the capsule. 
Strangely enough I. trigouocarpa is said to differ from /. prismatica chiefly by its stolonifcrous 
character, which is precisely the most striking peculiarity of the latter.] 
I. Carolina, ‘Radius, Beschreib. neuer Pflanzen, p. 158 (1822). 
Steud. Nomencl. ed. II. i. p. 821 (1840). 
Distribution. Marshy ground along the Atlantic Coast from Nova Scotia to Carolina. 
Cape Breton, Louisberg, 1883, Macoun (BM). 
Maine Marshes, Beyr (B). 
Massachusetts, Andover, 1880, Blake (K). 
Boston, Schweinitz (K). 
Boston, 1830, Boot (B). 
Bigelow (BM). 
Connecticut, A. Gray (BM). 
New York, Arlington and Staten Island, 1903, Henser (B). 
Newdorp, Staten Island, 1890, Small (W). 
New Jersey, 1832 and 1841, Torrey (E). 
1865, Henser (B). 
Rhode Island, Newport, 1883, Tweedy (B). 
Delaware, Wilmington, Canby (K) (B). 
Carolina and Georgia Mts, Buckley (BM). 
Diagnosis. 
I. prismatica imberbis, I. sibiricae haud dissimilis sed rhizoma late repens ; caulis tenuis, solidus ; 
germen triquetrum, alis conspicuis ; spatharum valvae scariosae. 
Description. 
Rootstock , a very slender rhizome, sending out long thin stolons, which appear at some distance 
from the old stem. 
Leaves , narrowly ensiform, acuminate, 24 by | in., glaucous, finely but not prominently ribbed. 
Stem, solid, slender, wiry, bearing a reduced leaf and usually a side branch, 18 — 24 in. high. 
The terminal head is 2 — 3-flowered and the side branch 1 -flowered. 
Spathe valves, acuminate, scarious, narrow, about 1 in. long. 
Pedicel, 1 — 2 in. long, increasing eventually to 3 or 4 inches. 
Ovary, trigonal, with the corners so much exaggerated as to be almost wings. 
Tube, very short but comparatively broad. 
Falls. The relatively long haft expands into a small ovate blade and bears at its base two 
small flanges not so conspicuously marked as is usually the case with I. sibirica. The haft and the 
base of the blade are marked with violet veins on a greenish-white ground. The rest of the blade 
is pale violet with deeper veins. 
Standards, lanceolate, violet, with a short canaliculate haft. 
Styles, arched, narrow. 
Crests, divergent, quadrate, with serrated upper edge, revolute. 
Stigma, a triangular tooth. 
Filaments, equal in length to the anthers, pale violet or red purple. 
Anthers, deep bluish-purple. 
Pollen , cream. 
Capsule, trigonal with sharp projecting ridges running down each angle. 
Seeds, buff-coloured, smooth, pyriform, more or less compressed and tending therefore to be cubical. 
