Dielsiris M.B.Crespo, Mart.

Crespo, Manuel B., Martínez-Azorín, Mario & Mavrodiev, Evgeny V., 2015, Can a rainbow consist of a single colour? A new comprehensive generic arrangement of the ‘ Iris sensu latissimo’ clade (Iridaceae), congruent with morphology and molecular data, Phytotaxa 232 (1), pp. 448-450 : 448-450

22. Dielsiris M.B.Crespo, Mart. -Azorín & Mavrodiev, gen. nov. [ Iris sect. Longipetalae Diels in Engl. & Prantl, Nat. Pflanzenfam. ed. 2, 15a: 502 (1930)]. Type (holotype):— D. longipetala (Herb.) M.B.Crespo, Mart. -Azorín & Mavrodiev [≡ Iris longipetala Herb. in Hook. & Arn., Bot. Beechey Voy. 9: 395 (1840)]

Genus notabilis Americae boreo-occidentalis ab Iride s. str. praecipue differt foliis herbaceis, mollibus linearibusque; floribus 1–6, tubo perigonii breve, cylindrico, ad faucem dilatato, exterioribus segmentis perigonii majoribus, erectis vel erecto-patentibus, laevibus vel costatis, costa centrali valde prominente, imberbibus, interioribus erectibus vel erecto-patentibus, minoribus, a basi brreve unguiculatis subplanis; lamella stigmatica bilobata, lobis integris vel crenatis; capsula fusiformibus vel oblong-ovoidea, coriacea, 6-costata, costis plerumque equidistantibus, oscure trigona, e apice deorsum a medio valde dehiscente; seminibus globosis vel pyriformibus, apiculatis, rugosis, exarillatis. Numeri basici chromosomatum, p = 8 et p = 11. Nomen genericum a Friedrich Ludwig Diels (1874–1945) ex animo dicatum.

64 • Phytotaxa 232 (1) © 2015 Magnolia Press

CRESPO ET AL.

Rhizomatous herbs, with persistent aerial structures. Rhizome stout, long, many-branched, sometimes creeping, clothed with dark remains of leaves; roots numerous, fleshy. Stems aerial, elongated, simple or 1–2-branched, solid, ± rounded in cross section. Leaves isobilateral, herbaceous, linear, ± glaucous, without prominent ribs, not fetid; caulinar well-developed, equitant. Flowers terminal on branches, in clusters of 1–6, shortly pedicellate. Spathe valves 2, scarious or herbaceous with apex and margins scarious, keeled, usually distant. Perigone in 2 rows, differing in size and shape, fused in a short cylindric tube, widened at the apex; falls erect-patent, obovate, slightly reflexed towards apex, entire, gradually tapering into a short claw, smooth or with a prominent central ridge; standards erect to erect-patent, oblong to spatulate, acute to emarginate, narrowed into a short haft. Stamen filaments free, adnate to the fall bases. Ovary trilocular, with axile placentation. Style filiform, with 3 petaloid branches, about half longer than falls, each one concealing a stamen; crests short, incurved, broadly triangular, subquadrate, irregularly fringed on margins; stigma bilobed, with entire or crenate lobes. Capsule oblong-ovoid to fusiform, usually with 6 equidistant ridges, obscurely subtrigonous, dehiscing from apex to about middle, usually not hidden into spathes, unbeaked; pericarp coriaceous. Seeds numerous, globose to pyriform, apiculate, without fleshy appendages; testa surface wrinkled. p = 8, 11. Figs. 5J , 25B .

It includes 5 species, occurring in central and western North America, namely in the Rocky Mountains area (from western Canada to northeastern Mexico) ( Fig. 24B ).

Needed new combinations:— Dielsiris arizonica (Dykes) M.B.Crespo, Mart. -Azorín & Mavrodiev, comb. nov. Basionym: Iris arizonica Dykes, Gard. Chron. ser. 3, 61: 45 (1917). Dielsiris longipetala (Herb.) M.B.Crespo, Mart. -Azorín & Mavrodiev, comb. nov. Basionym: Iris longipetala Herb. in Hook. & Arn., Bot. Beechey Voy. 9: 395 (1840). Dielsiris missouriensis (Nutt.) M.B.Crespo, Mart. -Azorín & Mavrodiev, comb. nov. Basionym: Iris missouriensis Nutt., J. Acad. Nat. Sci. Philadelphia 7: 58 (1834). Dielsiris pariensis (S.L.Welsh) M.B.Crespo, Mart. -Azorín & Mavrodiev, comb. nov. Basionym: Iris pariensis S.L.Welsh, Great Basin Naturalist 46: 256 (1986). Dielsiris pelogonus (Goodd.) M.B.Crespo, Mart. -Azorín & Mavrodiev, comb. nov. Basionym: Iris pelogonus Goodd., Bot. Gaz. 33: 68 (1902) [ I. montana Nutt. ex Dykes, Gen. Iris : 91 (1912) nom. illeg.].

Figures

FIGURE 5. Flower morphology: falls, standards and stylar branches, sometimes with spathe bracts (cont.). A) Hermodactylus tuberosus (photo: Paul Tyerman); B) Syrianthus grant-duffii (photo: Gideon Pisanty); C) Xiphion xiphium (photo: Mario Martínez- Azorín); D) Xiphion heracleanum (photo: Alicia Vicente); E) Alatavia kolpakowskiana (photo: Joyce Fingerut); F) Chamaeiris foetidissima (photo: Mario Martínez-Azorín); G) Chamaeiris graminea (photo: José Quiles); H) Chamaeiris reichenbachiana (photo: José Quiles); I) Chamaeiris anguifuga (photo: Jim Murrain); J) Dielsiris longipetala (photo: Ken Walker); K) Rodionenkoa gracilipes (photo: Ken Walker); L) Lophiris cristata (photo: Ken Walker).

FIGURE 24. Approximate distribution areas: A) Chamaeiris (red); B) Dielsiris (yellow).

FIGURE 25. Habit and floral details. A) Chamaeiris anguifuga (photo: Jim Murrain); B) Dielsiris missouriensis (Baker 1881: t. 6579); C) Rodionenkoa gracilipes (Hemsley 1903: t. 7926); D) Lophiris cristata (Small 1924: t. 320).