Plant Syst. Evol. 228: 33±48 22001) A reassessment of Normania and Triguera Solanaceae) L. Bohs1 and R. G. Olmstead2 1Department of Biology, University of Utah, Salt Lake City, UT, USA 2Department of Botany, University of Washington, Seattle, WA, USA Received August 8, 2000 Accepted April 2, 2001 Abstract. Normania and Triguera comprise two investigation of speciation, adaptive radiation, genera of the Solanaceae whose anities have been morphological specialization, and long dis- uncertain. Normania encompasses two species tance dispersal in plants. Island endemics often endemicto Macaronesia; Triguera is monotypic exhibit highly divergent morphologies com- and found in Spain and northwestern Africa. Both pared to their mainland relatives and in many have slightly zygomorphic¯owers and horned cases these disjunct but evolutionarily close anthers that dehisce by both apical pores and relationships have been clari®ed only with the longitudinal slits. Micromorphological similarities include trichotomously colporate pollen grains and recent advent of molecular data. Such is the seed surface cells with radially thickened exten- case with several endemic Macaronesian taxa sions. Molecular data from the chloroplast ndhF of the Solanaceae. Olmstead and Palmer gene and the nuclear ITS region establish that 21997) included the Macaronesian endemic Normania and Triguera are nested within the large Solanum vespertilio in their phylogeneticstudy genus Solanum, where together they form a well based on chloroplast DNA restriction frag- supported clade. However, the relationship of this ment variation, but the systematicplacement clade to other Solanum subgroups is not resolved. of the other endemicsolanaceoustaxa has not Transfer of the Normania and Triguera epithets to been examined using molecular data and their Solanum is made, necessitating one new name. The nearest relatives have not been identi®ed with molecular data con®rm that the species of Solanum certainty. endemic to Macaronesia belong to two distinct The purpose of this study is to elucidate the clades, each showing an independent evolution of heteromorphicanthers. systematicposition of two small and enigmatic genera of the Solanaceae, Triguera and Nor- Key words: Normania, Triguera, Solanum, Macaro- mania. Triguera is monotypicand native to the nesia, ndhF, ITS. Iberian peninsula and northwestern Africa. Normania includes two species endemic to the Since the time of Darwin 21845), oceanic Macaronesian islands of Madeira and the islands have served as living laboratories for Canaries. Both have been placed in subfamily the study of evolutionary questions. Research- Solanoideae, tribe Solaneae, which includes ers have targeted archipelagos such as the genera with ¯attened seeds, curved embryos, Galapagos, Macaronesia, and the Hawaiian generally valvate corolla aestivation, and and Juan Fernandez Islands as sites for basi®xed anthers. Because of their unusual 34 L. Bohs and R. G. Olmstead: A reassessment of Normania and Triguera 2Solanaceae) distribution and aberrant morphology, the apparently elongate into longitudinal slits. The relationships of these two genera have been style is straight, ca. 5±7 mm long and included, obscure and misunderstood. Molecular data and the stigma is minute. The fruits are now oer the opportunity to examine the globose berries with a dry or membranous phylogeneticposition of these taxa within the texture, ca. 10 mm in diameter, and are Solanaceae and clarify the close anity be- subtended by the somewhat accrescent folia- tween them, as has been suggested by previous ceous calyx. Each fruit contains 4±6 large, authors 2Lowe 1872, Francisco-Ortega et al. dark brown, deeply pitted seeds. 1993). All previous Solanaceae taxonomists have Triguera osbeckii was ®rst described by recognized Triguera as a distinct genus. Miers Linnaeus 21753) as a species of Verbascum,a 21849a) suggested that Triguera is closely allied genus later assigned to the Scrophulariaceae. with Solanum on the basis of its stamen In 1786, Cavanilles erected the genus Triguera structure and corolla aestivation. He reiterates and described the new species T. ambrosiaca this view in another paper 2Miers 1849b), in Cav. and T. inodora Cav. The genus Triguera which he lists Triguera in the tribe Solaneae Cav. 21786; Solanaceae) is conserved over along with the genera Solanum, Lycopersicon, Triguera Cav. 21785; Bombacaceae; Farr et al. and Cyphomandra. D'Arcy 21991) likewise 1979). Gmelin in 1791 described another new associated Triguera with other poricidally species in the genus, T. baccata J. F. Gmel. dehiscent genera such as Solanum, Lycopersi- Subsequent authors 2e.g. Poiret 1808, Roemer con, Cyphomandra, and Lycianthes. Molecular and Schultes 1819, Sprengel 1825, Miers phylogeneticstudies have resulted in the 1849a, Willkomm 1870, Hawkes 1972) recog- placement of Lycopersicon and Cyphomandra nized two to three species in Triguera, but within Solanum, and have established that Hansen and Hansen 21973) consider it likely Lycianthes is probably distinct from Solanum that the genus is monotypic, with T. osbeckii 2Spooner et al. 1993; Bohs 1995; Bohs and 2L.) Willk. as the only species. However, Olmstead 1997, 1999; Olmstead and Palmer Hansen and Hansen 21973) were unable to 1992, 1997; Olmstead et al. 1999). None of reach a conclusion about the identity of these molecular studies have examined the T. inodora, whose type has not been located. phylogeneticplacementof Triguera. In all probability, T. inodora is either a The unusual distribution and ¯oral mor- synonym of T. osbeckii or represents a taxon phology of Normania have attracted the unrelated to Triguera. attention of several previous workers. The Triguera osbeckii ranges from southern genus consists of two species, N. nava and Spain to adjacent northern Africa in Morocco N. triphylla, both endemicto Macaronesia. and northwestern Algeria. It is a small herb or Normania nava is one of the rarest species of weakly woody shrub, apparently annual, with Macaronesia and is restricted to the islands of alternate, sessile, obovate, coarsely dentate Tenerife and Gran Canaria in the Canary leaves. The ¯owers are solitary or paired in Island archipelago. Only two living plants of the leaf axils, and have rather large, foliaceous this species have been found since the time of calyces densely covered with curled, un- its original description in the ®rst half of the branched, whitish hairs. The rotate-campanu- nineteenth century 2Francisco-Ortega et al. late corolla is dark purple, shallowly ®ve-lobed 1993). Normania triphylla is likewise rare in at the apex, and slightly zygomorphic. The ®ve its natural range on the island of Madeira. stamens are equal or subequal in size and However, seeds gathered from a single wild shape, the ®laments short 2ca. 1 mm long), plant in 1994 were taken to the National with short 24±5 mm) anthers that dehisce by Botanical Conservatory in Brest, France, terminal pores located beneath two small where plants were successfully cultivated apical horns. As the anthers age, the pores and have even became locally naturalized L. Bohs and R. G. Olmstead: A reassessment of Normania and Triguera 2Solanaceae) 35 2R. Lester, pers. comm.). Seeds have been Dunal because of their supposed basal pedicel distributed to various botanicgardens and articulation. Lowe 21872) later transferred Solanaceae specialists. these species to his new genus Normania and Like Triguera osbeckii, the species of proposed that they were closely related to the Normania are herbs to weakly woody short- genus Triguera. Later botanists did not recog- lived shrubs. The stems and leaves are covered nize Normania and included N. triphylla and with soft, unbranched, often glandular hairs. N. nava within Solanum 2Bentham 1876, Bitter The leaves of both Normania species are 1912, D'Arcy 1972, Child 1990). Bitter 21912) membranaceous and elliptic-ovate in outline, disagreed with placement of the two species with those of N. triphylla usually pinnately near the potato group 2section Tuberarium lobed or dissected. The in¯orescences are Bitter) and moved them into his new section pedunculate, unbranched, and relatively few- Normania. D'Arcy 21972) and Child 21990) 2less than 15-) ¯owered. Calyces are large, retained Bitter's section Normania, but con- leafy, and soft-pubescent as in Triguera sidered it to be included in subgenus Potatoe osbeckii. The corolla is purple, rotate-campa- 2G. Don) D'Arcy. Most recently, Francisco- nulate, shallowly ®ve-lobed, and slightly zygo- Ortega et al. 21993) have supported recogni- morphic2Fig. 1). Despite these similarities tion of Normania as a separate genus within with Triguera, the ¯owers of both Normania the tribe Solaneae due to its distinctness in species are distinct due to their remarkable macro- and micromorphological characters. stamens. The ®ve anthers dier greatly in size They suggested a close relationship with and structure: two are long 26±11 mm) and Triguera on the basis of similarities in overall curved, two are shorter 24.5±8.5 mm) and also morphology and in pollen and seed structure. curved, and one is quite short 23±4.5 mm). The Whether recognized as Normania or consid- four longer anthers have a projection or horn ered as Solanum, the phylogeneticposition of at the middle or near the base. Although a N. triphylla and N. nava has not been resolved. small pore is apparent near the tips of the Four of the solanaceous species endemic to longer anthers, they mainly dehisce by a Macaronesia 2Normania nava, N.