A new Hawaiian Gahnia (Cyperaceae)

Herba perennis. Rhizoma breve, crassum, lignosum, squamis castaneis striatis obtectum. Culmi elati, usque ad 3 m alti, 2—4 mm crassi, teretes, glabri, usque ad apicem foliati et fere per totam longitudinem in vaginis foliorum absconditi. Folia culmum superantia, cinereo-viridia, tenacia, margine involuta, e basi dilatata 6—9 mm lata in acumen longissimum apice setaceo-caudatum scabrum gradatim angustata; vaginae longae, inferiores spadiceae vel atrofuscae, superiores stramineae; ligula angusta, rotundata vel in foliis superioribus triangularis, glabra, castanea. Inflorescentia paniculata, erecta, perangusta, (15—) 30—50 cm longa, 1—2(—3) cm lata, interrupta, e fasciculis 5—7 panicularum partialium elongato-oblongarum satis densarum constructa; rami 2—3-nim fasciculati, stricte erecti, inferiores ad 8 cm, superiores ad 2 cm longi. Bracteae inferiores foliis similes, inflorescentiam superantes, erectae, longe vaginantes, superiores gradatim decrescentes. Spiculae numerosae, oblongae, c. 7 mm longae, 2 mm latae, uniflorae, breviter pedunculatae; pedunculi scabri. Glumae 4, difformes: exteriores 2 vacuae, lanceolatae, acutae, acuminato-aristatae, carinatae, carina scabrae, resp. et 7 mm longae, nucem superantes, interiores 2 ovatae vel oblongo-ovatae, concavae, apice obtusae, margine apice ciliolatae, 4 mm longae, florem hermaphroditam arcte includentes. Perigonium nullum. Stamina 4; filamenta post anthesin persistentes, elongata, inter se et cum stylo intertexta, basi nucis affixa, nucem maturam delapsam retentia. Stylus tenuis, c. 3 mm longus, stigmatibus 3 filiformibus c. 8 mm longis. Nux dura, obtuse trigona, fusiformis, apice basique acuminata, laevis, demum nigra, nitens, 4—5 mm longa, 1½ —2 mm lata; endocarpium transverse annulato-sulcatum, sulcis 5—6. HAWAII. Lanai, east of Munro trail and north of Lanai-hale, in shrubby rain-forest at 3000 ft, Sept. 4, 1963, end of flowering season, culms up to 3 m high where supported by neighbouring bushes, Otto & Isa Degener 28431 (L, type); West edge of Munro trail at Lanai-hale, open scrubby fog-belt at 3370 ft, July 23, 1963, end of flowering season, forming 3—10 dm wide tussocks with 3—20 dm, erect-spreading culms, Otto & Isa Degener 28430 (L); Lanai-hale, in shrubby rain-forest at 3370 ft, young fl., Jan. 7, 1964, Otto & Isa Degener 28686 (L)