Resurrection of the genus Selleophytum (Asteraceae: Coreopsideae)

Transcription

1 Nordic Journal of Botany NJB Resurrection of the genus Selleophytum (Asteraceae: Coreopsideae) Mesfin Tadesse and Daniel J. Crawford Mesfin Tadesse & Crawford, D. J Resurrection of the genus Selleophytum (Asteraceae: Coreopsideae). Nord. J. Bot. 24: Copenhagen. ISSN X. After thorough morphological examination, a consideration of chromosome numbers and molecular studies, the genus Selleophytum is resurrected. A description of the only known species in the genus with an illustration is provided A neotype is selected. Mesfin Tadesse, The Ohio State University, Department of Evolution, Ecology, and Organismal Biology, Museum of Biological Diversity, 1315 Kinnear Road, Columbus, Ohio, , USA. tadesse.1@osu.edu. D. J. Crawford, University of Kansas, Natural History Museum & Biological Diversity Center, Haworth Hall, room 6010B, 1200 Sunnyside Ave., Lawrence, KS , USA. dcrawfor@ku.edu. Introduction The genus Selleophytum was established in 1915 (Urban 1915) to accommodate a species that was collected in Haiti, Morne la Selle. It was related to Zinnia, with which it was compared on features of the capitulum, phyllary and the corolla [probably referring to the ray florets]. The holotype, Buchanan 1137, was kept in Berlin and was probably destroyed. Blake (1924) transferred the species to Coreopsis and kept it in Coreopsis section Electra (DC.) Blake on the basis of the characters of the leaves, i.e., entire, sessile, cordate-based, lanceolate or lance-elliptic, and the solitary or ternate heads. This treatment was accepted by Sherff (1936, 1955). Smith (1975), however, viewed the species as a discordant element in sect. Electra. He indicated that the species does not fit into any section of Coreopsis, and suggested that it might better be segregated as Selleophytum or placed in Bidens despite its fertile ray flowers. Despite misgivings about the proper placement of the species, Smith (1975) made no taxonomic changes. Recent molecular studies (Kimball & Crawford 2004), a review of chromosome numbers (Crawford 1970a, b, 1981, 1982; Smith 1975), and morphological studies reported herein allow for a critical assessment of the relationships of Coreopsis buchii and its appropriate taxonomic disposition. A phylogeny of the Coreopsideae generated from ITS sequences placed C. buchii in a strongly supported clade with other island genera, viz Narvalina, Fitchia and Oparanthus. Fitchia and Oparanthus are morphologically and geographically far removed from Coreopsis buchii. Narvalina is currently known as a monospecific genus with only the original species, N. domingensis Cass. of the Dominican Republic. All other taxa previously placed in Narvalina have been transferred to Ericentrodea (2 species, cf. Robinson 1993), Lasianthaea (1 species, cf. Strother 1999) and Cyathomone (1 species, cf. Blake 1923). Cassini (1825) related Narvalina domingensis (as Needhamia domingensis Cass.) to Bidens and stated that it is essentially not different from Bidens. Achenes in Narvalina are described as retrorsum Accepted

2 Table 1. Comparison of the genus Selleophytum with Coreopsis mutica, C. parvifolia, and C. cuneifolia. A summary of the characters of the section, i.e., C. sect. Electra (DC). Blake is also included. Characters Selleophytum C. mutica C. parvifo. C. cunei. C. sect. Electra Chromosome number x = 16 2n = 56, 112 2n = 112 2n = 28 x = 14 Capitula shape Campanulate Cylindric Cylindric Cylindric Cylindric Inflorescence Solitary, rarely Cymose Solitary or Solitary or Cymose, up to 3 per branch cymose cymose rarely solitary Corolla tube hair Stiff bristles Capitate- Capitate- Ciliate Capitate glandular glandular glandular or ciliate Disc corolla color Purple or yellow Yellow Yellow Yellow Yellow Anther color Yellow Dark brown Dark brown Dark brown Dark brown to black to black Anther size (mm) Style length (mm) Style branch length Inner phyllary color margin Orange-red Yellow Yellow Yellow center Reddish-orange Yellowish-brown Yellowish-brown Orange-brown Yellowish- or orange-brown Leaf margin Entire Serrate 3-5-dentate Serrate Serrate Achene Shape Oblong-linear, Oblanceolate, Oblanceolate Elliptic Oblanceolate, oblong-elliptic oblongelliptic Cross-section Quadrangular Flat Flat Flat Flat Margin Not-winged Narrowly Narrowly Narrowly Flattened, winged winged winged wing-like Hairs Setose on Glabrous Glabrous Glabrous Glabrous margins and ridges Width (mm) Surface 8-striate-sulcate Faintly 6-ribbed Shiny Shiny Smooth, shiny Pappus 2, antrorsely 0; rarely 2 in 0 0 0; rarely 2 in barbed inner achenes, inner achenes, nude nude 2

3 hispidis (Bentham & Hooker 1873) or retrorsely barbed and leaves sharply dentate (Bremer 1994).Coreopsis buchii, having features that are similar to Coreopsis than Bidens, was thus compared with the three species placed in Coreopsis sect. Electra (Table 1, as Selleophytum). Members of Creopsis sect. Electra have the unique base chromosome number for the genus of x = 14. Creopsis cuneifolia is diploid with 2n = 28 (Crawford 1970a), C. mutica is either tetraploid or octoploid (2n = 56, 112) (Crawford 1970 b, 1981) and C. parvifolia is octoploid with 2n = 112 (Crawford 1982), Coreopsis buchii has a chromosome number of 2n = 64 (Smith 1975) which suggests that it is a tetraploid based on a base number of x = 16. On the basis of chromosome number, C. buchii does not fit in Coreopsis (Smith 1975). A base chromosome number of x = 16 appears to be quite rare in the Coreopsideae (with 14 genera), with the exceptions being Dahlia, Hidalgo (Robinson et al. 1981) and Bidens (Mesfin 1984, 1986). Coreopsis buchii, as shown above, is different from both Bidens and Narvalina and, as indicated in Table 1 (as Selleophytum), it differs from the members of Corepsis sect. Electra, in a number of important features of the achene (overall shape, shape in cross-section, margins, pubescence, width and pappus), anther size and color, pubescence and color of the corolla, and color of inner phyllaries, all major reproductive characters used in separating genera and species. The leaf margins are entire whereas in the other species, the leaves are distinctly serrate. The chromosome number is also based on x = 16, a feature unknown in Coreopsis, although recorded in Bidens and Dahlia in the Coreopsideae. On the basis of the features discussed, the genus Selleophytum is resurrected and the sole species is returned to it from Coreopsis. Selleophytum buchii Urban Repertorium Specierum Novarum Regni Vegetabilis, vol.13(376/377):484 (1915). Coreopsis buchii (Urb.) Blake, Contr. U.S. Nat. Herb. 22: 641 (1924); Sherff, Field Mus. Nat. Hist., 11: 302 (1936); E. E. Sherff in E. E. Sherff & E. J. Alexander (eds), North American flora, Ser. 2(2):5 & 9 (1955). Type: Haiti, Morne le Selle, in sylvis apricis, 1800 m alt., m. Jan. flor. Et fruct., Buch no [B, holotype, destr.]. Neotype: Haiti, Massif de la Selle, Morne de la Selle, Camp Franc, 1550 m, 26 Jan. 1925, E. L. Ekman 3074 (F!; NY!, isoneotype). Shrub, m high; branches terete, striate, internodes cm long, glabrous, lower ones leafless. Leaves simple, opposite, sessile, cm, oblong-lanceolate to narrowly ovate, glabrous, coriaceous, light green, base cordate-cuneate, tapering to a short pseudopetiole or sessile, rarely broad and cordate, margins entire or inconspicuously undulate, midvein prominent with many parallel, anastomosing lateral veins, apex acute to acuminate. Capitula solitary or up to 3 terminating main stem or branches, radiate, campanulate, 3-5 cm wide at anthesis, peduncle erect, 3-6 cm long, slightly expanded below the receptacle, glabrous, striatesulcate. Involucre 8-15 mm wide. Receptacle flat, 6-7 mm wide in fruit. Outer phyllaries green, 5-6, glabrous, coriaceous, subulate to lanceolate, 5-nerved at base, each with a pair of striae, mm, apex acute. Inner phyllaries orange-red, 8, coriaceous, glabrous, oblong-lanceolate, mm, margins scarious, apex obtuse. Ray florets yellow, pistillate, fertile, aristate, tube mm long, ciliate, rays mm, with striations, oblong-elliptic, apex 2-lobed to minutely 3-fid. Palea reddish, oblong, oblong-lanceolate, 3-5-striated, mm at anthesis, glabrous. Disk florets corolla yellow or purple, tubular, pubescent below, hairs bristly or stiff, glabrous above, mm long, 5-lobed, lobes c. 1 mm long, glabrous. Anthers yellowish-brown, mm long, connective mm long with resin duct up to the middle or near the apex. Style bifurcate, mm long, branches 2-3 mm long, stigmatic surface c. 1.5 mm long, apex conic, penicellate. Achenes oblong-linear, gray brown, sub-quadrangular, not winged, densely short setose at the margin and near the apex, 8-striate-sulcate on both surfaces, mm, apex biaristate. Pappus aristae antrorsely barbed, triquetrous, mm long, barbs of stiff hairs. Fig. 1. Note: In most of the specimens examined, the flowers are described as yellow, bright yellow or orange without distinction between ray and disc floret color. In a few more recent collections (e.g., Judd 4888) color is noted as ray and disk flowers yellow and in others we find the following notes: disk flowers deep purple (Judd et al NY); disk flowers dark (Liogier NY); with yellow flowers and purplish (Judd 1468-GH). Habitat: Open Pine forest on limestone cliffs; alt m. Distribution: Haiti and Dominican Republic. Specimens studied: Haiti: Vicinity of Fond Parisien, 3

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5 Etang, Saumatre, May 5-13, 1920, E.C. Leonard 2013 (US, photo at F!); Massif de la Selle, Morne de la Selle, Camp Franc, 1550 m, 26 Jan. 1925, E. L. Ekman 3074 (F, NY); Dept. de L Ouest, Massif de la Selle, ridges to the west of Pic La Selle, m, 22 May 1984, W. S. Judd and Dan Cordier 4888 (GH); Terre Froide, Morne la Selle, 1400 m, 5 Aug. 1942, L. R. Holdridge 1393 (F, NY); Santo Domingo (Dominican Republic), largo del rio de la Cueva, La Horma Arriba, 1400 m, 3 Jan. 1974, A. Liogier (F, NY); Cordillera de Baharuco, prov. de Barahaua, Sierra de los Comisarios, 1700 m, 29 Aug. 1926, E. L. Ekman 6791 (F, NY); Prov. Pedernales, near Aceitillar, in the Sierra de Baoruco, 1250 m, 14 May 1976, W. S. Judd 1468 (GH), along Alcoa Exploration Co. Road, ca. 40 km N of Cabo Rojo, m, 23 July 1981, W. S. Judd et al (NY); S. of Aceitillar on Alcoa Aluminum Co. Rd. in the Sierra de Baoruco, 1150 m, 14 May 1976, W. S. Judd 1471 (GH, NY); Canote-Los Guiritos, W of Aceitillar, Sierra del Bahoruco, Pedernales, 9 Feb. 1969, A. H. Liogier (GH, NY); trail between Pedernales and Aceitial, 4200 ft., 8-12 Aug. 1946, R. A. & E. S. Howard 8151 (GH, NY); Rancho Viejo. South of Puerto Escondido, 23 July 1950, R. A. Howard (GH); Pedernales, Aceitillar, Sierra de Barouca, 30 km N of Puerto de Cabo Rojo, m, 12 April 1985, Al Gentry & M. Mejia (MO); Sierra de Baoruco, Regalo tract, 1550 m, 8 Nov. 1979, G. L. Smith (NY); Aceitillar, Bahoruco Mts., 1000 m, Feb. 1971, F. Votava & A. H. Liogier 111 (NY); Cayo, Aceitillar, 1200 m, July 1973, A. H. & Perfa Liogier (NY); Cordillera Central, Prov. Peravia, 24.6 km N of Parque Central de San Jose de Ocoa, 3200 ft, 25 Dec. 1981, T. Zanoni (NY); 16 km desde San Jose de Ocoa, 2100 ft., 18 Nov. 1981, T. Zanoni et al (NY); Aceitillar, Bahoruco Mts., 1300 m, 26 Feb. 1971, A. H. Liogier (NY); Aceitillar, 23 March 1967, Marcano 5262 (NY); ca km N of San Jose de Ocoa, above La Horma on road to Valle Nuevo, 1050 m, W.S. Judd et al (NY). Acknowledgements We would like to thank the directors and curators of the following herbaria for the loan of specimens: F, GH, MO, NY, US. References Bentham G Compositae. In: Bentham G. & Hooker, J. D., Genera Plantarum, 2(1): London. Blake, S. F New American Asteraceae. Contrib. U. S. Nat. Herb. 22: Bremer K Asteraceae: Cladistics and Classification. Timber Press, Portland, Oregon. Cassini, H Needhamia. In: Dictionnaire des Sciences Naturelles, vol. 34: Paris. Crawford, D. J. 1970a. Systematic studies on Mexican Coreopsis (Compositae). Coreopsis mutica: Flavonoid chemistry, chromosome numbers, morphology and hybridization. Brittonia 22: b. Titel? In: IOPB chromosome number reports. XXV. Taxon 19: A new variety of Coreopsis mutica (Compositae) from Mexico. Brittonia 33: Chromosome numbers and taxonomic notes for Mexican Coreopsis, sections Electra and Pseudoagarista (Compositae: Heliantheae). Brittonia 34: Kimball, R. T. & Crawford, D. J Phylogeny of Coreopsidae (Asteraceae) using ITS sequences suggests lability in reproductive characters. Molecular Phylogenetics and Evolution 33: Mesfin Tadesse, The Genus Bidens (Compositae) in NE tropical Africa. Symb. Bot. Uppsal. 24(1): Uppsala, Sweden. Mesfin Tadesse & Hedberg, I Titel? In: IOBP Chromosome Number Reports, XC. Taxon 35: 196. Robinson, H New Species of Ericentrodea from Bolivia and Colombia (Asteraceae, Coreopsidinae, Heliantheae). Novon 3: , Powell, A. M., King, R. M. & Weedin, J. F Chromosome numbers in Compositae, XII: Heliantheae. Smithsonian Contributions to Botany 52. Sherff, E. E Revision of the Genus Coreopsis. Field Mus. Nat. Hist., Bot. Ser. 11: Coreopsis. In: Sherff, E. E. & Alexander, Initials?????. Compositae Heliantheae Coreopsidinae. North Amer. flora 2 (2): Smith, E. B The chromosome numbers of North American Coreopsis with phyletic interpretations. Botanical Gazette 136: Strother, J. L Compositae Heliantheae s.l. In Flora of Chiapas 5: Urban, I Sertum antillanum II. In: Repertorium Specierum Novarum Regni Vegetabilis. 13 (376/377): Fig. 1. Selleophytum buchii Urban. A. flowering branch. B. Outer phyllary. C. Inner phyllary. D. Ray floret. E. Palea. F. Disc floret. G. Stamen with part of filament. H. Style with stylopodium. I. Achene with 2 pappi and a cross-sectional view. Line bars: A = 1 cm. B = 2 mm.c-i = 1 mm. A from W. S. Judd 1471 (GH). B-H from Liogier (F). I from Judd 1471 (NY). 5