Cyrtandra tuiwawai M.A.Johnson, 2020

Johnson, Melissa A., 2020, Revision of Cyrtandra tempestii (Gesneriaceae) and the description of Cyrtandra tuiwawai from Taveuni, Fiji, Phytotaxa 429 (4), pp. 251-260 : 256-259

Cyrtandra tuiwawai M.A.Johnson , sp. nov.

Figs. 5 , 6

Type:— FIJI. Taveuni: Des Voeux Peak, along the road to the summit, 1036 m elev., 16°50.24’ S, 179°58.30’ W, 13 July 2014, M.A. Johnson 83 with G.J. Hora (holotype RSA!, isotype RSA!, SUVA!).

Diagnosis:— Cyrtandra tuiwawai differs from C. tempestii in having dense, appressed, purplish-black pilose trichomes on younger structures (vs. sparse brown pilose trichomes on younger structures), dark green, glabrous leaves to 25 × 11 cm (vs. green pubescent leaves to 43 × 17 cm), fewer flowers per cyme (1–8 vs. 9–17), calyx with moderately dense purplish-black pilose trichomes on outer surfaces (vs. sparsely brown pilose trichomes), and corolla yellowish-white, the tube 14–17 mm long and 5–8 mm wide (vs. corolla white, the tube 18–20 mm long and 6–7 mm wide).

Description:— Shrub up to 3 m tall; stems branched near the base, with dense appressed purplish-black pilose trichomes when young. Leaves opposite, borne on upper 5–8 nodes, internodes 2–6 cm long, blades elliptic to elliptic ovate, 17–25 cm long and 8–11 cm wide, upper surface dark green and glabrous, lower surface light green and glabrate except veins densely purplish-black pilose, 7–9 secondary veins on each side, margins undulate to finely serrate, apex acute to acuminate, base strongly oblique, petioles 3–9 cm long with appressed brown pubescence; inflorescence an axillary cyme, appressed purplish-black pilose throughout, 1–8 flowers, peduncle 7–13 mm long, terminated by lanceolate bracts, 2–4 mm long, deciduous after anthesis, pedicels 11–15 mm long; calyx white, outer surface pilose with moderately dense purplish-black pilose trichomes, inner surface glabrous, lobes linear lanceolate and equally cleft nearly to the base, 9–15 mm long, deciduous; corolla yellowish-white, tube funnelform, slightly curved, 14–17 mm long and 5–8 mm wide, outer surface glabrous, inner surface with short glandular trichomes near the mouth of the tube and dense short white pubescence covering the lobes, upper lobes 5–8 mm long and 4–7 mm wide, lower lobe 8–11 mm long and 6–10 mm wide; stamens 2, filaments 4.8 mm long, white with an orange spot near the base, anthers 1.2 mm long, connate at the apex; staminodes 3, 1–2 mm long, adnate 1–2 mm below filaments and opposite the posterior sinuses; nectary disc annular, cupulate, to 2 mm high, drying to a pelviform structure, persistent in mature fruit; gynoecium (ovary, style, stigma) 10–11 mm long, ovary glabrous, style sparsely pubescent with capitate glandular trichomes, stigma applanate, bilobed; berries ellipsoid to ovoid, 14–22 mm long and 9–13 mm wide, glabrous, turning white at maturity.

Distribution and ecology:— Cyrtandra tuiwawai is only known with certainty from the cloud forest summit of Des Voeux Peak (1036–1210 m elevation) on Taveuni, Fiji ( Fig. 3 ). Smith’s collection from “dense forest W of an old crater occupied by a swamp and small lake (660–900 m elevation)” was likely from an area 2–3 km W of the road to Des Voeux Peak (J. Game, pers. comm.).

Phenology:— Individuals of this species have been observed to flower and fruit in April, July, August, October and November.

Etymology:— This species is named for Marika Tuiwawa, Curator of the South Pacific Regional Herbarium at the University of the South Pacific in Fiji. For his dedication to the conservation of Fiji’s flora, his valuable insights into Fijian Cyrtandra , and his kind assistance with fieldwork logistics and permits in Fiji that made this publication possible, I gratefully extend him due recognition.

Phylogenetic placement:— A recent phylogenetic study by Johnson et al. (2017) supported Cyrtandra tuiwawai as sister (79 BS, 95 PP) to a clade comprising C. mareensis Däniker (1933: 78) (Lifou, Loyalty Islands) and C. schizocalyx Gillett (1974: 704) (Espiritu Santo, Vanuatu; Fig. 4 ). Like C. tuiwawai , C. schizocalyx also grows in high-elevation montane wet forest (Y. Pillon, pers. comm.), and shares the white calyces that also characterize C. tuiwawai . In contrast, C. mareensis grows in coastal shrublands and on limestone cliffs (Y. Pillon, pers. comm.), and resembles C. samoensis in overall appearance. However, C. mareensis shares several floral characters with C. tuiwawai , including deciduous white calyces that are equally cleft nearly to the base.

Conservation status:— Proposed IUCN Red List Category: Endangered (EN) based on an estimated area of occupancy of <500 km 2 (criterion B2); known to exist at no more than five locations (B2a); projected decline in extent of occurrence; area of occupancy (B2bii); and area, extent, and/or quality of habitat (B2biii). Threats to this species include clearing along roadsides, invasive species (M. Johnson, pers. obs.), and damage from tropical cyclones. The montane forests of Taveuni remain relatively unexplored, exceptions being the forest along the road to Des Voeux Peak and the area surrounding Lake Tagimoucia. Additional surveys are needed to more fully characterize the distribution of this species and document threats to its continued survival.

Additional specimens examined:— FIJI: Taveuni : Hills E of Somosomo, W of old crater occupied by small swamp and lake, 660–900 m elev., 18 August 1953, Smith 8388 (NY!, UC!, US!) ; summit of Des Voeux Peak in stunted ridge-top cloud forest, 1210 m elev., 22 April 1993, Regalado & Vodo 585 (BISH!, GH!, NY!) ; beside Des Voeux Peak Rd. , 1080 m elev., 18 November 2016, Game 16/216 ( PTBG!) ; near Des Voeux Peak Rd. , 1191 m elev., 10 October 2017, Game 17/170 ( UC!) .

Notes:— Four other Cyrtandra species were observed to grow sympatrically with C. tuiwawai on Des Voeux Peak ( C. ciliata , C. hispida Johnson (2017: 92) , C. leucantha Smith (1953: 41–42) and C. chippendalei Horne ex Clarke (1883: 230–231)) . Although all five species were flowering simultaneously, no morphologically intermediate (i.e., inter-specific hybrid) individuals were observed. Individuals of C. leucantha , C. tuiwawai and C. ciliata appeared to occur with some frequency along the roadside, with C. hispida and C. chippendalei being less common in the area.

Figures

FIGURE 3. Distribution of Cyrtandra tempestii Horne ex C.B.Clarke and C. tuiwawai M.A.Johnson on Taveuni, Fiji. The location of the single individual referred to as C. aff. tempestii collected from Lavena is also noted.

FIGURE 4. A portion of the Maximum Likelihood phylogram from Johnson et al. (2017) based on three nuclear (ITS, ETS, Cyrt1) and two chloroplast (psbA-trnH, rpl32-trnL) loci. Support values shown for each branch are bootstrap (BS) and posterior probabilities (PP) when ≥ 50% and ≥ 0.50, respectively.An asterisk indicates 100% BS or 1.0 PP; a dash indicates that the branch was not supported.

FIGURE 5. Cyrtandra tuiwawai M.A.Johnson A Habit B Inflorescence with buds, an older flower, and developing young fruit C Corolla and calyx of younger flower, lateral view D Corolla, anterior view E Dissected corolla, showing stamen insertion, details of the gynoecium, and staminodes F Close-up of three staminodes G Fruits. Drawn by Liv-Monique Johnson from M.A. Johnson 83 (RSA, SUVA) and field photographs by M.A. Johnson.

FIGURE 6. Cyrtandra tuiwawai M.A.Johnson A Habit B Inflorescence, lateral view C Flower, anterior view D Young (green) and mature (white) fruits. All photographs taken in the field by M.A. Johnson.