A New Species of Villarsia (Menyanthaceae) from South Africa

Abstract

A second African species of Villarsia, V goldblattiana, is described from South Africa. The genus otherwise is Australian (13 species) and southeastern Asian (1 species). Villarsia goldblattiana differs from V capensis in its larger ovule number, glabrous seeds, longer calyx lobes, taller inflorescences, and apparent requirement of fire to induce flowering. It is known only from the southern Cape Peninsula. Both South African Villarsia species are tetraploid with 2n = 36. An emended description of V capensis is given, and the origin and location of its holotype and of the holotypes of the synonyms Menyanthes ovata L. f. and M. capensis Thunberg are discussed. The only species of Villarsia (Menyanthaceae) currently recognized in Africa is V capensis (Houttuyn) Merrill of Western Cape Province (Marais & Verdoorn, 1963; Dyer, 1975). Elsewhere, there are 13 species of the genus in Australia (Aston, 1969; Ornduff, 1990) and an additional one in southeastern Asia (Omrnduff, 1994). As traditionally circumscribed, Villarsia capensis exhibits interpopulation variability in habitat, leaf size, and floral characters. I have suggested that further study of the South African plants may result in the recognition of more than one species (Ornduff, 1974). Recently, I examined specimens of South African Villarsia borrowed from BOL and NBG and concluded that a second species of Villarsia occurs in South Africa. I am naming it Villarsia goldblattiana in recognition of Peter Goldblatt's significant contributions to southern African botany, particularly the systematics and reproductive biology of the Iridaceae, and in appreciation for his considerable assistance in my study of Villarsia in South Africa. Villarsia goldblattiana Omrnduff, sp. nov. TYPE: South Africa. Western Cape Province: growing abundantly in shallow standing water of marsh, N of road to Olifantsbos, 1.7 mi. W of its junction with main road to Cape Point Nature Reserve, 5 Feb. 1971, Ornduff 7099 (holotype, sheet I, NBG; isotype, sheet II, NBG). Figure 1. Villarsiae capensi affinis sed differt in characteribus pluribus: inflorescentia 45-84 cm elata, 1.8-vel 2.5-plo longior quam folium longissimum; calycis lobi 6-14 mm longi, 2-3 mm late basi; ovaria ovulis 3-8; semina glabra. Erect, tufted, non-stoloniferous perennial. Basal leaves erect, evergreen, with petioles 12-32 cm long; blades fleshy, oblong to ovate, 4-9 cm long, 1.5-8 cm wide, attenuate to cordate at base, entire. Inflorescence an open panicle with 16-55 flowers, 45-85 cm tall, the tallest 1.8-2.5 times the length of the longest leaves, with cauline leaves gradually reduced upward to scales. Flowers distylous, open or only one day, on pedicels 1-2 cm long. Corolla yellow, the 5 obovate lobes about twice the length of the calyx lobes, the margins fimbriate, with hairs on parts of the upper surface. Calyx lobes 5, + lanceolate, 6-14 mm long, 2-3 mm wide at the base. Ovules 3-8 per ovary. Capsules ovoid, equaling or slightly longer than the calyx lobes. Seeds glabrous, yellow, ? orbicular, biconvex, 1.5-2 mm diam. Wet soil and marshes, Cape Peninsula. Near sea level to 600 m. Flowers October to January, reportedly after fire. Paratypes. SOUTH AFRICA. Western Cape Province: .. in summo monte 'Steenberg' alt. circa 800 ped., Dec. 1903, L. Kensit s.n. (BOL); Muizenberg Plateau, Nov. 1913, E. Kensit s.n. (BOL); Noord Hoek Mts., alt. 2000 ft., 2 Jan. 1945, Compton 16898 (BOL, NBG); Cape Point, Patrys Vlei, 24 Nov. 1946, Compton 18826 (NBG); Smitswinkel Flats, Cape Peninsula, 29 Oct. 1942, Compton 14007 (NBG). Villarsia goldblattiana has 3-8 ovules per ovary, glabrous seeds, calyx lobes that are 6-14 mm long, and inflorescences that are 45-85 cm tall and 1.82.5 times the length of the longest leaves. It grows from near sea level to 600 m in elevation and is known only from the southern Cape Peninsula, where it has been collected on the slopes above Noordhoek and the Steenberg plateau south to the Smitswinkel Flats in the Cape Point Nature Reserve. It is reported to flower after a fire (Fraser & McMahon, 1994; P. Salter, pers. comm. 1997). I suspect that the primary effect of fire is to increase light intensity by temporarily reducing the shading that is caused by an overstory of fynbos shrubs. I revisited the type locality of this species in early September 1998, but was unable to find any plants NOVON 9: 407-409. 1999. This content downloaded from 207.46.13.148 on Sun, 11 Sep 2016 04:11:19 UTC All use subject to http://about.jstor.org/terms