Research Article |
Corresponding author: Benny Bytebier ( bytebier@ukzn.ac.za ) Academic editor: João Farminhão
© 2023 Benny Bytebier.
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:
Bytebier B (2023) Eulophia edwardii (Orchidaceae), a new species from the Pondoland Centre of Endemism in South Africa. Plant Ecology and Evolution 156(3): 326-332. https://doi.org/10.5091/plecevo.105931
|
Background and aims – Despite the fact that the orchid flora of South Africa is well documented, new species are still being discovered. The identity of an Eulophia subpopulation from near Port Edward in KwaZulu-Natal has been ambiguous. Some thought that it belongs to Eulophia schnelliae, currently considered a synonym of Eulophia macowanii, whereas others were of the opinion that it was potentially a new species. Both hypotheses are investigated here.
Material and methods – Plants were studied in the field and herbarium specimens, including types, were consulted. The relevant published literature was revised.
Key results – Eulophia schnelliae is confirmed as a synonym of Eulophia macowanii. The Port Edward subpopulation does not match any known Eulophia taxon and is newly described as Eulophia edwardii, endemic to the Pondoland Centre of Endemism. It is only known from one subpopulation of about 200 individuals, which is threatened by urban development. It is, therefore, assessed as Critically Endangered according to Criterion B2ab(i,ii,iii).
Conclusion – The newly described species increases the number of Eulophia species in South Africa to 29 and the number of endemic Eulophia species to 10. This discovery underlines the need for continued botanical inventories and protection of sensitive grasslands.
Cymbidieae, Eulophiinae, KwaZulu-Natal, new species, Orchidaceae, Pondoland
The terrestrial epidendroid orchid genus Eulophia R.Br. ex Lindl. is widespread in the tropical and subtropical areas of Africa, Asia, and the Americas. It is most diverse in tropical and southern Africa, particularly in the dambos (shallow wetlands), grasslands, and miombo woodlands of south-central Africa (
Eulophia in the traditional sense (
Eulophia (sensu stricto) contains approximately 165 species (
Here, I investigate the identity of an Eulophia population from near Port Edward in KwaZulu-Natal, South Africa, which was discovered back in 2008 by a group of orchid enthusiasts lead by Martin Rautenbach. These plants did not match the circumscription of any of the South African Eulophia species and could not be immediately named.
Forty herbarium specimens from BOL, GRA, NBG, NH, NU, PRE, and SAM (
The only known population of the new taxon was visited by the author in February 2014 and 2015, during the flowering period, to record basic morphometric data and to collect herbarium material for further study.
The preliminary IUCN conservation assessment was done following the guidelines in the IUCN Red List Categories and Criteria (
Comparison of the holotype specimen of Eulophia schnelliae (Schnell s.n. in Herb. Bolus 22,860 [BOL149961]) with specimens of Eulophia macowanii confirms the opinion of
Comparison of the Eulophia material from Port Edward with the holotype of Eulophia schnelliae and specimens of E. macowanii clearly shows that these belong to two different taxa. Flowers of the Port Edward plants are fully resupinate at anthesis, whereas those of E. schnelliae and E. macowanii are not resupinate. The papery sheaths on the peduncle of the Port Edward plants are always overlapping, whereas those in E. schnelliae cover at maximum only half the size of the internode, and those in other E. macowanii specimens only occasionally reach the base of the sheath above. Furthermore, these sheaths are of a much firmer texture. Flowering time of E. schnelliae is November and peak flowering of E. macowanii is November/December, whereas the Port Edward plants consistently flower in mid to late February. King William’s Town (now called Qonce), the type locality of E. schnelliae, is 40 km inland from the sea, whereas the Port Edward plants are just a few hundred meters from the beach and in coastal grassland. Furthermore, as the crow flies, King William’s Town is about 335 km from Port Edward. Thus, assigning the Port Edward plants to E. schnelliae was an error of judgment most likely resulting from comparison of photos of these plants with the painting in the protologue of E. schnelliae (
A specimen from this population was included in the phylogenetic analysis of
SOUTH AFRICA – KwaZulu-Natal • Port Edward, Rennies Beach; 31°04’S, 30°12’E; 15 m; 8 Feb. 2015; fl.; B. Bytebier, K.W. Grieve & G.R.H. Grieve 3501; holotype: NU [NU0094001]; isotypes: BR, NH, NU [NU0094003].
Eulophia edwardii is morphologically most similar to E. macowanii, but differs from E. macowanii by having fully resupinate flowers at anthesis vs non-resupinate in E. macowanii, by having white petals vs creamy-yellow petals; and by having papery, overlapping sheaths on the peduncle vs more sturdy, non-overlapping sheaths or occasionally the tip of one sheath only just reaching the bottom of the next one. It differs from E. ovalis by having spreading petals instead of petals that cover the column and are bent over the lip.
Eulophia edwardii. A. Habit. B. Anther cap: side view and view from below. C. Pollinarium. D. Column: front and side view. E. Petal. F. Lip. G. Sepal. H. Pedicel, ovary, median sepal and part of lip showing spur. I. Apex of spur. J. Papillae on lip. K. Side view of flower. L. Front view of flower. M. Leaves. Figure drawn by Kate Grieve.
Terrestrial herb, 220–325 mm tall. Perennating organs subterranean, forming a beaded rhizome up to 110 mm long with up to 7 globose to ovoid tuberous units, each 15–20 mm in diameter and 10–17 mm tall, covered with fibrous remains of leaf bases; roots white, up to 170 mm long × 3–5 mm wide. Leaves 5–9, fully developed at anthesis, arranged in an arcuate fan, plicate, linear to linear-lanceolate, acute, the uppermost up to 270 mm long × 20 mm wide, the lowermost 2–3 much smaller and dry at anthesis. Inflorescence erect, lax to subdense, 5–14-flowered; peduncle slender, 2–3 mm in diameter, covered with 6–8 papery, overlapping sheaths, up to 115 mm long × 14 mm wide; rachis 30–50 mm with papery, lanceolate to elliptic, acuminate bracts 15–17 mm long × 5–9 mm wide, slightly shorter than the ovary. Flowers fully resupinate at anthesis, sepals brownish green to green, petals and lip white, papillae pale yellow, spur greenish to greenish brown. Sepals spreading; median sepal 19–22 mm long × 6–7 mm wide, apex acute to attenuate; lateral sepals 23–25 mm long × 7–9 mm wide, apex acute to attenuate. Petals spreading, 21–25 mm long × 10–14 mm wide, ovate to elliptic, apex obtuse to rounded. Lip 3-lobed, 19–21 mm long × 20–24 mm wide; side lobes elliptic to obovate, 12 mm long × 6 mm wide; midlobe orbicular with 3 undulate ridges in basal third and 3 tomentose veins on either side of the ridges, ridges passing into relatively few, long, slender, branched papillae ending abruptly midway along the lip. Spur 5 mm, conical to cylindrical, slightly dorsoventrally flattened, incurved and often slightly bifid at apex. Column 5–6 mm. Anther cap 1.5–2 mm wide, beaked. Pollinia 2 attached to stipe of 1 mm. Ovary 19–29 mm long. Fruit ellipsoidal, pendent.
Growing in moist, hygrophilous, lightly sloping, windswept, species-rich coastal grassland, dotted with clumps of Strelitzia nicolai Regel & Körn. CREW (Custodians of Rare and Endangered Wildflowers) Pondoland members have documented more than 370 species of indigenous angiosperms on this piece of land, including 16 other orchid species (Kate Grieve and Graham Grieve pers. comm.).
Flowering in February (end of summer).
Named in honour of Edward (Ted) George Hudson Oliver for his lifelong dedication to botany, particularly the study of Ericaceae and Orchidaceae. Indirectly, it also refers to Port Edward, so far, the only place where this taxon is known to occur.
Critically Endangered: CR B2ab(i,ii,iii). As far as can be judged from repeated monitoring by the author and the CREW Pondoland team, the subpopulation is stable, and although the number of flowering individuals (the only possible way of counting the individual plants) changes from year to year, the maximum number of flowering specimens has never been more than an estimated 200. These occur in one subpopulation spread out over an area of about one hectare (B2a). CREW Pondoland has surveyed the very few remaining patches of coastal grassland near Port Edward in KwaZulu-Natal, as well as several along the Eastern Cape Pondoland coast. Despite numerous efforts, no additional subpopulations have so far been traced. A decline in the extent of occurrence (B2bi), area of occupancy (B2bii), and extent and quality of habitat (B2biii) is inferred in view of the fact that north of the Mtamvuna river (as far north as Durban, which is well beyond the limits of the Pondoland Center of Endemism) almost no untransformed grasslands close to the sea and matching the type locality still exist. North of Durban, coastal grasslands in proximity to the highwater mark do not exist until near the mouth of the Tugela. The loss of comparable habitat in KwaZulu-Natal is now nearly complete at least over this 225 km of coastline between the Mtamvuna and Tugela Rivers. A further decline of potential habitats is almost not possible as they are all already lost, making this species highly vulnerable to a catastrophic event, such as an attempt to develop the plot, which borders an important, interprovincial road and is close to the beach. The land on which the plants occur is currently privately owned and is unprotected, despite the fact that it contains 13 Pondoland endemics, six Near Threatened, five Vulnerable, one Endangered (Eriosema umtamvunense C.H.Stirt.), and one Critically Endangered (Hyobanche fulleri E.Phillips) species (http://redlist.sanbi.org). Furthermore, it has four species of Indigofera that have just been described (
SOUTH AFRICA – KwaZulu-Natal • 3130AA; Port Edward, Rennies Beach; 10 m; 18 Feb. 2010; Abbott 9097; PCE [PCE0007850] photo, PRU, NU spirit • ibid.; 6 Feb. 2013; K.W. Grieve 726; NU spirit • ibid.; 17 Feb. 2014; Bytebier 3477; NU spirit • South of Port Edward; 27 Feb. 2011; Church & Goodman s.n.; BR, NU.
Apart from the diagnostic characters mentioned above, there are several, more subtle differences between E. edwardii and E. macowanii. The former has between 6 and 8 papery leaf sheaths, whereas the latter has seldom more than 5 leaf sheaths, which are of a firmer texture. The longest leaf sheath, found in the middle of the peduncle, is on average 80 mm in the former (and up to 115 mm), whereas in the latter it is seldom more than 60 mm. The lateral sepals are 7 mm wide or more in the former whereas they are seldom more than 6 mm in the latter. The width of the lip is usually more than 20 mm in the former and seldom more than 17 mm in the latter. Eulophia edwardii flowers in mid to late February, while most records for E. macowanii are from November and December. Eulophia macowanii is endemic to the Eastern Cape province, whereas E. edwardii occurs in KwaZulu-Natal (Fig.
The following modification to the key to Eulophia in
40a | Leaves less than half the length of the scape at anthesis; spur 1.2–2.2 mm long; crest papillae few, confined to the basal 1/3 of the lip midlobe | E. cooperi |
40b | Leaves usually more than 2/3 length of the scape at anthesis; if less, then the spur more than 3 mm long and crest papillae numerous over most of lip | 41 |
40c | Leaves approximately half the length of the scape at anthesis; spur 5 mm long; crest papillae few, branched and restricted to middle of the lip | E. edwardii |
The author wishes to thank CREW Pondoland and particularly Kate and Graham Grieve for their knowledge, enthusiasm, and assistance, the curators of BOL, GRA, K, NBG, NH, and PRE for sending specimens on loan. Florent Martos is thanked for assistance in the field. Kate Grieve provided the drawing; and Graham Grieve, as well as Florent Martos, provided photographs, which are reproduced here with permission. Adam Shuttleworth assisted with Fig.
Appendix 1. Material examined of Eulophia macowanii.
SOUTH AFRICA – Eastern Cape • Frasers Camp; 11 Jan. 1947; Compton R.H. 19095; NBG [NBG0056558-0] • 3128DA; Umtata; 27 Nov. 1954; Lowry C. s.n.; BOL [BOL69482] • 3128DB; Umtata, Unitra Campus; 18 Nov. 1982; Hutchings A. 50; GRA • 3128DB; ibid.; 28 Nov. 2001; Peter C. 429; NU [NU0005494] • 3128DB; Umtata; Dec. 1915; McLoughlin A.G. 4174; BOL [BOL69481] • 3226DB; Chumie Peak; 1884; Sculy W.C. 173; BOL [BOL69484] • 3227CB; Dohne Peak; 27 Jan. 2001; McMaster J.C. DP 2701; NBG [NBG0182626-0] • 3227CD; King William’s Town; 28 Nov. 1942; Schnell I.A. s.n.; BOL [BOL69483, BOL149961] • 3227CD; Mount Coke; 457 m; 1891; Sim T.R. 20111; PRE [PRE0053622-0] • 3227DB; Komgha; 609 m ; Dec. 1893; Flanagan H.G. 2254; BOL [BOL73224], PRE [PRE0053609-0] • 3228CB; Kei Mouth; 30 m; Jan. 1892; Flanagan H.G. 1033; PRE [PRE0053610-0] • 3228CB; ibid.; 30 m; Jan. 1892; Flanagan H.G. 1032; PRE [PRE0053611-0] • 3228CC; Gonubie; Mar. 1980; Howe W. s.n.; GRA • 3325CD; Bridgemead; 175 m; 21 Jan. 1997; Dold T. 2482; GRA • 3325DC; Frames Drift; Feb. 1917; Holland M.A. 18; BOL [BOL73221] • 3326BD; Oribi Reserve; 375 m; 11 Jan. 1995; Dold T. 1252; GRA • 3326BD; Trappe’s Valley; 19 Dec. 1965; Bayliss R.D.A. 3083; NBG [NBG0083410-0] • 3326BD; Trappe’s Valley; 26 Dec. 1903; Ansley E. 15; PRE [PRE0053621-0] • 3326CB; Alexandria; 213 m; 24 Jan. 1955; Acocks J.P.H. 17879; PRE [PRE0053615-0] • 3326DA; Hayes Siding; 28 Nov. 1983; Weeks D.C. 127; GRA • 3326DA; Bushmans River; Jan. 1932; Holland F.H. 3815; BOL [BOL51691, BOL73225] • 3326DB; Port Alfred; 29 Mar. 1903; White G. 73; GRA • 3326DB; Kowie West; Feb. 1917; Tyson W. s.n.; BOL [BOL73222]; 3326DB; Kowie; Aug. 1915; Tyson W. 16845; BOL [BOL73223] • 3326DB; ibid.; 60 m; 9 Nov. 1895; Galpin E.E. 3025; PRE [PRE0053620-0] • 3326DB; Port Alfred; 1893; South B. s.n. PRE [PRE0053613-0] • 3326DB; Bathurst; 1890; South B. s.n.; PRE [PRE0053616-0] • 3326DB; ibid.; Sep. 1915; Marloth H.W.R. 8523; PRE [PRE0053612-0] • 3326DB; Kowie; Dec. 1890; Hutton H. 1215; BOL [BOL149962] • 3326DB; Bathurst; 10 Jan. 1974; Retief E. 310; PRE [PRE0611551-0] • 3326DB; Kowie; MacOwan P. s.n.; PRE [PRE0053619-0] • 3326DB; ibid.; Jan. 1907; Britten L.L. 10813; PRE [PRE0053614-0] • 3326DB; Kowie; 518 m; Dec. 1890; Hutton H. 1215; SAM [SAM0020352-0] • 3327BA; Kidd’s Beach; Dec. 1943; Giffen M.H. FH 1770; PRE [PRE0540057-0] • 3327BB; East London; Dec. 1888; Thode J. 7716; NBG [NBG0182627-0] • 3327BB; East London Cemetery; 30 m; Dec. 1926; Smith C.A. 3787; PRE [PRE0053617-0] • 3327CA; Kleinemund River; MacOwan P. 1280; BOL [BOL69485].