Research Article |
Corresponding author: Melissa A. Johnson ( melissa.johnson@cgu.edu ) Academic editor: Eric Roalson
© 2017 Melissa A. Johnson.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Johnson MA (2017) Four new species of Cyrtandra (Gesneriaceae) from the South Pacific islands of Fiji. PhytoKeys 91: 85-104. https://doi.org/10.3897/phytokeys.91.21623
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During fieldwork in Fiji, four new species of Cyrtandra (Gesneriaceae) were discovered and are described herein: C. gregoryi M.A.Johnson, sp. nov., C. hispida M.A.Johnson, sp. nov., C. longifructosa M.A.Johnson, sp. nov., and C. waisaliensis M.A.Johnson, sp. nov. The addition of four new species brings the current number of Fijian Cyrtandra to 41 endemic species. Two of the four species are known from only a single locality, and all of the new species are likely endangered or critically endangered. Continued fieldwork in the islands of Fiji is warranted in order to better understand current species distributions and population demographics of Cyrtandra in this species-rich and still poorly explored region of the South Pacific.
Cyrtandra , Gesneriaceae , Fiji, South Pacific, islands, new species, taxonomy, conservation
The Southeast Asian-Pacific genus Cyrtandra J.R. Forster & G. Forster (Gesneriaceae) comprises ca. 800 species, with centers of diversity in Borneo, New Guinea, the Philippines, and the Pacific islands (
Recent phylogenetic studies suggest that Cyrtandra evolved in Southeast Asia, followed by dispersal to the Pacific islands (
Botanical explorations in Fiji from 1840–1953 resulted in the description of all 37 currently recognized species of Fijian Cyrtandra. Since the 1960s, relatively few collections of Fijian Cyrtandra have been made. In the 1970s, a number of new roads were built in Fiji to accommodate the expanding agricultural industry, vastly increasing accessibility into remote regions (e.g., central Vanua Levu, eastern Taveuni;
Diagnoses of the new species are based on morphological traits and DNA sequence variation in a phylogenetic context. Morphological measurements were taken from live plants in the field, as many characters essential to Cyrtandra identification are lost upon drying (particularly floral characters). Information was also taken from liquid fixative-preserved flowers and fruit, as well as from digital photographs. To ensure accurate identification, comparisons were made with all existing species descriptions (
Cyrtandra gregoryi is closely related to C. ciliata Seem. (Fig.
FIJI. Taveuni: near the end of the Lavena coastal walk along the Wainibau stream, ca. 3.5 km NW of Lavena Village, 16°52.10'S, 179°54.32'W, 32 m elev., 04 August 2014, M.A. Johnson 105 with G.J. Hora (holotype: RSA).
Cyrtandra gregoryi M.A.Johnson and closest relative (C. ciliata) based on a molecular phylogeny by
Shrub 0.9–2.2 m tall; stems unbranched to few-branched, with a dense indument of dark brown uniseriate multicellular trichomes ca. 0.5 mm long. Leaves opposite, internodes 2–7 cm long, blades elliptic to ovate to obovate, 22–39 cm long, 7–17 cm wide, upper surface sparsely strigillose, lower surface glabrate except for the densely pubescent 9–13 secondary veins on each side, margins serrulate to subentire, apex acute, base cuneate to rounded, petioles 5–11 cm long, densely pubescent with short brown trichomes; inflorescence an axillary cyme with dense brown pubescence on the peduncles and pedicels, 3–22 flowers, cymules 1–4 flowered, peduncle to 31 mm long, terminated by bracts to 6 mm long, narrowly lanceolate, deciduous after anthesis, pedicels to 31 mm long; calyx 6–13 mm long, outer surface pale green and moderately pubescent with appressed dark brown uniseriate trichomes, inner surface white and papillate, unequally cleft into 5 lanceolate coriaceous lobes, 3–10 mm long, apex acuminate, upper lobes occasionally connate, often continuing to split along two or three sutures and curl back after anthesis, deciduous; corolla white, tube funnelform, slightly curved near mid point, 23–27 mm long, 6–9 mm wide, outer surface glabrate to densely pubescent with short glandular trichomes, inner surface glabrous, upper lobes 5–7 mm long and 5–6 mm wide, lower lobe 7–8 mm long and 5–6 mm wide, lobes recurving after anthesis; stamens 2, ca. 9 mm long, becoming exserted from the corolla tube during ovulate phase, base of the filaments bright orange, anthers apically connate, staminodes 3; nectary disc cupulate, annular; gynoecium (ovary, style, and stigma) 16–24 mm long, ovary glabrous, style pubescent with capitate glandular trichomes, exserted, stigma shallowly bilobed; fruit not seen.
Individuals of this species were in flower when collected in August and November, with fruits likely becoming mature ca. 5–6 months later.
I am pleased to name this new species after my husband, Gregory Hora, to whom I am most grateful for his assistance in collecting this and other species across Fiji.
A recent phylogenetic study by
A portion of the Maximum Likelihood phylogram from
Proposed IUCN Red List Category: Endangered (EN) based on an estimated area of occupancy of < 500 km2 (criterion B2), known to exist at no more than five locations (B2a), inferred decline in area of occupancy (B2bii), decline in area, extent, and/or quality of habitat (B2biii), decline in number of mature individuals (B2bv), and population size estimated to number fewer than 250 mature individuals (D).
Although Bouma National Heritage Park protects ca. 15,000 hectares of intact rainforest on eastern Taveuni, indigenous Fijians are permitted to clear land near villages for agriculture. As a result, large areas of coastal forest are increasingly being cleared for dalo (taro, Colocasia esculenta (L.) Schott) and yaqona (kava, Piper methysticum L.f.), the two main export crops of Taveuni. Given that C. gregoryi appears to be restricted to low-elevation forests, it is highly likely that individuals of this species were extirpated during clearing for human settlements and agriculture. Invasive plants are also a major threat to native plants in the area; mile-a-minute vine (kudzu, Pueraria lobata (Willd.) Ohwi) may be particularly problematic as it rapidly grows over trees and shrubs and can kill other plants with heavy shading. Lastly, anthropogenic-induced climate change is a threat to island plant communities. Tropical cyclones are expected to increase in intensity and severity in the coming years (Emmanuel 2005, Knutson 2010), and can have devastating effects on island vegetation due to high winds, flooding, and storm surges (e.g., Cyclone Pam in 2015 caused extensive damage to Vanuatu’s forests). Most recently, Cyclone Winston, the strongest tropical cyclone to make landfall in the South Pacific Basin in recorded history, ravaged the islands of Fiji in February of 2016. The coastal regions of eastern Taveuni were inundated by massive storm surges, and much of the vegetation was damaged by winds of up to 185 mph. Although forested regions can often regenerate after a natural disaster if given sufficient time, recent research in the South Pacific suggests that a cyclone can be a catalyst for human-coping strategies that increase pressure on forest ecosystems and exposes them to invasive plant species (
FIJI. Taveuni: Tavoro Falls Trail in Bouma National Heritage Park, 19 November 2016, J.C. Game 16/235 with S. Fawcett (PTBG).
Eight individuals of C. gregoryi were recorded during field surveys along the Lavena coastal trail, with all of these being reproductive. Additional field surveys in the area are likely to reveal more individuals. No other Cyrtandra species were observed growing sympatrically with C. gregoryi in the Lavena region, although C. tempestii Horne ex. C.B. Clarke was collected 0.64 km to the SE. An additional collection was made of a single individual of C. gregoryi near the Tavoro Falls in Bouma National Heritage Park, an area that also hosts C. ciliata.
Cyrtandra hispida is morphologically similar to C. waisaliensis sp. nov., but differs in its axillary cyme inflorescence of 2–4 flowers (vs. cauliflorous cyme inflorescence of 2–8 flowers), green bracts and bracteoles 5–9 mm long (vs. white bracts and bracteoles 3–10 mm long), calyx pale green and 29–31 mm long (vs. calyx white and 23–37 mm long), corolla tube 31–34 mm long (vs. corolla tube 23–27 mm long), and staminodes 2 (vs. staminodes 3).
FIJI. Taveuni: Des Voeux Peak, 16°50.48'S, 179°57.97'W, 1109 m elev., 13 July 2014, M.A. Johnson 91 with G.J. Hora (holotype: RSA; isotype: SUVA).
Cyrtandra hispida M.A.Johnson and closest relative (C. cephalophora) based on molecular phylogeny by
Shrub 0.6–1.2 m tall; stems unbranched or few-branched, with light brown hispid uniseriate multicellular trichomes ca. 5 mm long. Leaves opposite, internodes 3–9 cm long, the blades oval to ovate to obovate, 15–22 cm long, 8–10 cm wide, upper and lower surfaces densely strigose with light brown uniseriate trichomes to 2 mm long, 5–7 secondary veins on each side, margins serrate to biserrate, apex acute to acuminate, base oblique or aequilateral and rounded to cuneate, petioles 4–9 cm long, densely pubescent with hispid trichomes ca. 6 mm long; inflorescence an axillary cyme, 2–4 flowered, densely hispid throughout, peduncle 10–14 mm long, terminated by green bracts 5–9 mm long, ovate to narrowly lanceolate, densely hispid, pedicels 27–28 mm long, often subtended by bracteoles similar to the outer bracts; calyx pale green, cylindrical, 29–31 mm long, unequally cleft into five triangular lobes 4–11 mm long, outer and inner surfaces densely hispid with uniseriate trichomes, persistent on developing fruits; corolla white, bilabiate, tube narrowly funnelform, slightly curved near mid point, outer and inner surface glabrous, 31–34 mm long and 8–9 mm wide, upper lobes 12–15 mm long and 10–14 mm wide, lower lobe 13–20 mm long and 10–15 mm wide; stamens 2, ca. 7 mm long, anthers apically connate, staminodes 2; nectary disc cupulate, annular, deciduous from the fruit; gynoecium (ovary, style, and stigma) ca. 22 mm long, ovary and style glabrous, stigma applanate, bilobed; berries green when immature, ellipsoid, glabrous, up to 18 mm long and 11 mm wide, tipped by the basal 3 mm of the persistent style, enclosed by the persistent calyx, mature fruit not seen.
Cyrtandra hispida is only known from two populations in the upland rainforests of Taveuni, Fiji, where plants occur on exposed hillsides composed of volcanic cinders, and on rocky stream banks from 697–1126 m elevation (Fig.
Individuals of this species were in flower when collected in July, with fruits likely becoming mature ca. 5–6 months later (December–January).
This species is named for the stiff trichomes that cover the stems, leaves, and inflorescences.
A recent phylogenetic study by
Proposed IUCN Red List Category: Endangered (EN) based on an estimated area of occupancy of < 500 km2 (criterion B2), known to exist at no more than five locations (B2a), projected decline in extent of occurrence (B2bi), area of occupancy (B2bii), and area, extent, and/or quality of habitat (B2biii). Although the two areas where this species has been collected are within the Taveuni Forest Reserve, the forest above Somosomo Village is currently being cleared for a hydropower dam (M. Johnson, pers. obs.). Additional threats include mining for gold and copper, invasion by plant species such as Clidemia hirta (L.) D. Don (Koster’s curse; M. Johnson, pers. obs), and damage from tropical cyclones. Further surveys are needed in the upland forests of Taveuni (which remain relatively unexplored, exceptions being the area surrounding Lake Tagimoucia and the road to Des Voeux Peak) to determine the extent of occurrence and population demographics of C. hispida.
FIJI. Taveuni: mountains above Somosomo, 16°47.67'S, 179°56.10'W, 693 m elev., 24 August 2015, M.A. Johnson 212 (SUVA), M.A. Johnson 215 (RSA).
Cyrtandra hispida was observed to grow sympatrically with three species on Des Voeux Peak (C. leucantha A.C. Sm., C. ciliata, and Cyrtandrasp.) and three species in the mountains above Somosomo (C. leucantha, C. ciliata, C. taviunensis Gillespie). Several individuals were observed that appeared to be of hybrid origin in these populations, with the widespread and common C. ciliata inferred as one of the parents based on similar floral morphology. While the observation of ongoing hybridization in these populations suggests the possibility of C. hispida being of hybrid origin, none of the sympatric species have morphological characters similar to C. hispida. Furthermore, C. hispida is placed in a clade of species that are endemic to the neighboring islands of Vanua Levu and Viti Levu, and does not appear to be closely related to species endemic to Taveuni.
This species is closely related to C. dolichocarpa (Fig.
FIJI. Vanua Levu: ca. 0.8 km NE of Waisali Village along the Waisali Creek, 16°38.51'S, 179°14.54'E, 110 m elev., 09 July 2014, M.A. Johnson 65 with G.J. Hora (holotype: SUVA; isotype: RSA).
Cyrtandra longifructosa M.A.Johnson and closest relative (C. dolichocarpa) based on molecular phylogeny by
Shrub 0.9–1.7 m tall; stems unbranched to few branched. Leaves opposite, internodes 1–5 cm long, the blades narrowly elliptic to elliptic-ovate, 17–22 cm long, 7–9 cm wide, upper and lower surface glabrous, 8–10 secondary veins on each side, these slightly impressed, margins serrulate, apex acuminate, base oblique to aequilateral and attenuate to cuneate, petioles 3–9 cm long, glabrous to glabrate; inflorescence an axillary cyme, 1– 2(3–4) flowers, densely pilose with black trichomes ca. 1 mm long throughout, peduncle 2–4 mm long, terminated by green bracts, 3–8 mm long, lanceolate, deciduous after anthesis, pedicels 11–18 mm long; calyx pale green, outer and inner surfaces pubescent with appressed uniseriate trichomes, narrowly fusiform in bud, 28–32 mm long, beaked, the 5 lobes often remaining connivent, splitting along one suture 14–19 mm long, deciduous; corolla white, becoming strongly bilabiate in the ovulate phase, tube cylindrical, curved near the mid point, outer surface glabrous, inner surface with uniseriate trichomes throughout and short glandular trichomes near the mouth of the tube, the tube 23–29 mm long, 5–7 mm wide, upper lobes 8–12 mm long and 8–11 mm wide, lower lobe 12–14 mm long and 11–14 mm wide; stamens 2, ca. 6 mm long, base of the filaments reddish orange, anthers apically connate, staminodes 3; nectary disc cupulate, annular, deciduous from mature fruit; gynoecium (ovary, style, and stigma) ca. 24 mm long, ovary glabrous, style pubescent with capitate glandular trichomes along distal ⅓ of its length, stigma bilobed; berries cylindrical, elongate, mature fruit to 40 mm long and 5 mm wide, glabrous, turning white at maturity.
Individuals of this species had flowers, immature fruits, and mature fruits when collected in July.
Named for the elongate cylindrical fruits, one of the diagnostic characteristics of this species.
The phylogenetic study by
Proposed IUCN Red List Category: Critically Endangered (CR): based on an estimated area of occupancy of < 10 km2 (criterion B2), known to exist only at a single location (B2a), projected decline in extent of occurrence (B2bi), area of occupancy (B2bii), and area, extent, and/or quality of habitat (B2biii). This species is only known from one locality in the central mountains of Vanua Levu, warranting additional surveys in areas of Vanua Levu with intact rainforest (e.g., Waisali, the Natewa Peninsula) to determine the full extent of occurrence and population demographics of C. longifructosa. Regions with suitable rainforest habitat on Vanua Levu are threatened by logging, mining for bauxite and gold, invasive plant species such as Clidemia hirta (Koster’s curse; M. Johnson, pers. obs.), and tropical cyclones.
FIJI. Vanua Levu: NE of Waisali Village along Waisali Creek, 16°38.51'S, 179°14.54'E, 110 m elev., 09 July 2014, M.A. Johnson 59 with G.J. Hora (RSA).
The population of C. longifructosa was observed to contain ca. 20 individuals, many of which were reproductive. No other Cyrtandra species were observed growing in the immediate vicinity, although the closely related species C. dolichocarpa, C. waisaliensis, and C. cephalophora were all collected 2.25 km W of the C. longifructosa population described here.
The new species is closely related to C. dolichocarpa and C. longifructosa (Fig.
FIJI. Vanua Levu: Waisali Forest Reserve along the lower portion of the Savuqoro Creek, 16°38.39'S, 179°13.25'E, 338 m elev., 07 July 2014, M.A. Johnson 50 with G.J. Hora (holotype: SUVA; isotype: RSA).
Shrub 0.7–2.6 m tall; stems few- to many-branched, young stems covered in hirsute trichomes. Leaves opposite, those at a node unequal, internodes 2–8 cm long, blades ovate to obovate, 13–24 cm long, 6–12 cm wide, upper and lower surfaces densely hirsute with uniseriate multicellular trichomes, 6–7 secondary veins on each side, margins serrate, apex acuminate, base oblique to aequilateral and attenuate to cuneate, petioles 3–11 cm long, densely hirsute, trichomes ca. 5 mm long; inflorescence of cauliflorous cymes, 2–8 flowered, cymules 1–4 flowered, densely hirsute throughout, peduncle 3–8 mm long, terminated by persistent foliaceous white bracts, ovate to lanceolate, 3–10 mm long, outer surface glabrous to glabrate, inner surface densely hirsute, pedicels 21–40 mm long, subtended by multiple persistent bracteoles similar to and closely subtended by the outer bracts; calyx white, cylindrical, densely hirsute, 23–37 mm long, unequally cleft into 5 triangular lobes, 4–14 mm long, persistent; corolla white, bilabiate, tube funnelform, curved near mid point, outer surface glabrous to glabrate, inner surface with capitate glandular trichomes near the mouth of the tube, 23–27 mm long, 6–9 mm wide, upper lobes 11–12 mm long and 8–11 mm wide, lower lobe 13–17 mm long and 10–15 mm wide; stamens 2, 3–6 mm long, base of the filaments reddish orange, anthers apically connate, staminodes 3; nectary disc prominent, annular, 2 mm high; gynoecium (ovary, style, and stigma) 16–26 mm long, ovary glabrous, style pubescent with capitate glandular trichomes along distal ⅓ of length, stigma bilobed; berries ellipsoid, green when immature, enclosed by the persistent calyx, mature fruit not seen.
Cyrtandra waisaliensis is known only from one population in the Waisali Forest Reserve on Vanua Levu, Fiji at 300–360 m elevation, occurring in the dense forest understory alongside a creek (Fig.
Flowers and immature fruits were observed in July, with fruits likely becoming mature ca. 5–6 months later (December–January).
The new species is named after the area of Vanua Levu where it was collected, Waisali Forest Reserve.
A recent phylogenetic study by
Proposed IUCN Red List Category: Critically Endangered (CR) based on an estimated area of occupancy of < 10 km2 (criterion B2), known to exist at only a single location (B2a), projected decline in extent of occurrence (B2bi), area of occupancy (B2bii), and area, extent, and/or quality of habitat (B2biii). This species is only known from one locality in the central mountains of Vanua Levu, warranting additional surveys in areas of Vanua Levu with intact rainforest (e.g., Waisali, the Natewa Peninsula) to determine the full extent of occurrence and population demographics of C. waisaliensis. Regions with suitable rainforest habitat on Vanua Levu are threatened by logging, mining for bauxite and gold, invasive plant species such as Clidemia hirta (Koster’s curse; M. Johnson, pers. obs.), and tropical cyclones.
FIJI. Vanua Levu: Waisali Forest Reserve along the lower portion of the Savuqoro Creek, 16°38.34'S, 179°13.18'E, 355 m elev., 07 July 2014, M.A. Johnson 48 with G.J. Hora (RSA).
The observed population of C. waisaliensis was comprised of ca. 20 individuals, many of which were reproductive. A single individual appeared to be of hybrid origin, with the putative parents being C. waisaliensis and C. cephalophora based on morphological characters intermediate between these two species.
The recognition of C. gregoryi, C. hispida, C. longifructosa, and C. waisaliensis brings the new total of Fijian Cyrtandra species to 41. The four new species of Cyrtandra described here demonstrate that the islands of Fiji remain poorly explored botanically, at least in some regions. Of the 28 Fijian Cyrtandra species collected during field expeditions in 2014 and 2015, four of these were new to science. An additional four Cyrtandra species could not be keyed out to any of the existing species due to a lack of reproductive material. However, with further field study it is possible that these, along with other future collections, may be identified as new species.
I am grateful to Marika Tuiwawa, Alivereti Naikatini, Manoa Maiwaqa, Mereia Tabua, and Sarah Pene (South Pacific Regional Herbarium, The University of the South Pacific) for assistance with fieldwork logistics in Fiji. Collecting permits were granted by The Fiji Ministry of Education, export permits by Fiji Biosecurity, and import permits by the United States Department of Agriculture. I also thank my husband Gregory Hora for being an excellent field assistant and for providing endless encouragement and moral support. This work would not have been possible without the kind peoples of Fiji, who offered their assistance, expertise and hospitality. The following herbaria graciously allowed the use of their collections for study: BISH, GH, K, NY, RSA, SUVA, UC, US, and WU. John Game provided collection information and photographs of Cyrtandra gregoryi for study. Funding for this project was provided by the following: Rancho Santa Ana Botanic Garden; Garden Club of America Award in Tropical Botany; American Philosophical Society Lewis and Clark Fund for Exploration and Field Research; The Gesneriad Society Nelly D. Sleeth Scholarship Endowment Fund; The Gesneriad Society Elvin McDonald Fund; Society of Systematic Biologists Graduate Student Research Award; Sigma Xi Grants-in-Aid of Research; American Society of Plant Taxonomists Graduate Student Research Grant; and Claremont Graduate University. Lastly, I am grateful to my sister, Liv Johnson, for the beautiful line drawings, and to Lucinda McDade, John R. Clark, J. Travis Columbus, J. Mark Porter, David Lorence, and one anonymous reviewer for comments that greatly improved this manuscript.