Notas do Herbário Florestal do INRB (LISFA): Fasc. XXXII

∫1. Novarum Flora Lusitana Commentarii

In memoriam A.R. Pinto da Silva (1912 – 1992)

A new combination in Lotus glaucus complex (Fabaceae, Loteae) from Porto Santo (Madeira Archipelago)

 

Roberto Jardim, Centro de Ciências da Vida, Universidade da Madeira, 9000 - 390 Funchal, Portugal, rjardim@netmadeira.com;

Miguel Menezes de Sequeira, Centro de Ciências da Vida, Universidade da Madeira, 9000 - 390 Funchal, Portugal, sequeira@uma.pt

 

Lotus glaucus Aiton (Fabaceae, Loteae, section Pedrosia) from Madeira Island was the first described species of the Lotus glaucus complex (AITON, 1789). LOWE (1856) proposed a new genus, Pedrosia Lowe, to include the Macaronesian Lotus species with a distinct toothed style. In the same publication Lowe described a new species for Porto Santo Island, Pedrosia florida Lowe, that he distinguishes from P. glauca (Aiton) Lowe (L. glaucus), as follows:

"in its more silky, hoary foliage, lanceolate acute leaflets, larger, more numerous flowers, often four or five in a head, and larger, thicker, straighter, and even, instead of strangulato-torulose, pods".

Latter LOWE (1862, p.178), although recognizing P. florida as a distinct taxon, discusses its taxonomic status, clearly dismissing a species rank.

MASFERRER (1881) transferred P. florida to the genus Lotus as L. floridus and BRAND (1898) combined L. floridus as a variety of L. glaucus.

MENEZES (1914) considered P. florida within Lotus glaucus simply as a form. The subsequent Madeira flora authors do not recognize any taxonomical rank for P. florida (Costa, 1946, 1948; Pickering, 1962; Hansen, 1969; HANSEN & Sunding, 1985, 1993; Vieira, 1992; Turland, 1994; JARDIM & MENEZES DE SEQUEIRA, 2008).

Recently SANDRAL et al.(2006) studied the taxonomy of Lotus section Pedrosia and they also do not recognize taxonomically P. floridus (L. floridus), although they have studied some Porto Santo specimens they include P. florida as a synonymy of Lotus glaucus and also typified Pedrosia florida and P. florida var. sulphurea Lowe.

Traditionally Lotus glaucus was also recognized for all Canary Islands (e.g. HANSEN, 1985), but SANDRAL et al. (2006) refer to L. glaucus as an endemic species for the Madeira Archipelago. Distinguishing L. glaucus subsp. glaucus for Madeira, Porto Santo and Desertas and L. glaucus subsp. salvagensis (R.P.Murry) Sandral & D.D.Sokoloff. for Salvage Islands. Some specimens from Fuerteventura (Canary Islands) are considered by the same authors as uncertain, although others are included in a different species.

The examination of collected material and herbarium specimens (MADJ, MADS, MADM, LISU and MA) and field observations in Porto Santo, Madeira and Desertas show that the Porto Santo plants of Lotus glaucus agree with the description given by Lowe for Pedrosia florida (Figure 1). Table 1 summarizes the diagnostic characters and compares them with Lotus glaucus subsp. glaucus (Figure 2). The morphological resemblance of L. glaucus with L. floridus and the restricted distribution of the later to the Porto Santo Island clearly suggest that a subspecific rank should be applied, accordingly a new status is proposed for Lotus floridus:

Lotus glaucus Aiton subsp. floridus (Lowe) R. Jardim & M. Seq., comb. nov.

≡ Pedrosia florida Lowe in Hooker's J. Bot. Kew Gard. Misc. 8: 294 (1856) (bas.)

≡ Lotus floridus(Lowe) Masf. in Anales Soc. Esp. Hist. Nat. 10:160. (1881)

≡ Lotus glaucus Aiton var. floridus (Lowe) Brand in Bot. Jahrb. Syst. 25: 200 (1898)

= Pedrosia florida Lowe var. sulphurea Lowe, Man. Fl. Madeira 1: 178 (1862)

 

Table 1 - Diagnostic characters of Lotus glaucus subsp. glaucus versus L. glaucus subsp.floridus

 

Figure 1 - Lotus glaucus subsp. floridus (A, flowers and leaves; B, habit)

 

Figure 2 - Lotus glaucus subsp. glaucus  (Flowers, fruits, stems and leaves)

 

The original description of Pedrosia florida is here transcribed:

"P. fruticulosa sericeo-albicans foliolosa, foliolis confertis parvulis lanceolatis v. obovato-lanceolatis acutis stipulisque conformibus omnino sessilibus, umbellis 2-5-floris, leguminibus rectis cylindricis glabris.

Var. a; fl. laete aurantiacis.

Var. ß; fl. pallide sulphureo-stramineis.

HAB. In Portu Sancto".

 

Although some specimens with flower color corresponding to the description given by Lowe for Pedrosia florida Lowe var. sulphurea were studied, we agree with SANDRAL et al.(2006) in not recognizing them at any taxonomical rank.

Further studies should contribute to clarify the taxonomic relations between taxa included in the Lotus glaucus complex in Macaronesia.

 

References

AITON, W.,1789. Hortus Kewensis Vol. 3: 92 London.         [ Links ]

BRAND, A., 1898. Monographie der Gattung Lotus. Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie. 25: 166-232.         [ Links ]

COSTA, J.G., 1948. Lista Fitológica do Porto Santo. Boletim do Museu Municipal do Funchal 23(7): 55-65.         [ Links ]

HANSEN, A., 1969. Checklist of the Vascular Plants of the Archipelago of Madeira. Boletim do Museu Municipal do Funchal24: 1-77.         [ Links ]

HANSEN, A., SUNDING, P., 1985. Flora of Macaronesia, Checklist of vascular plants, 3. revised edition. Sommerfeltia 1: 1-167.         [ Links ]

HANSEN, A., SUNDING, P., 1993. Flora of Macaronesia, Checklist of vascular plants, 4. revised edition. Sommerfeltia 17: 1-295.

JARDIM, R., MENEZES DE SEQUEIRA, M., 2008. The vascular plants (Pteridophyta and Spermatophyta) of the Madeira and Selvagens archipelagos. In: BORGES, P.A.V., ABREU, C., AGUIAR, A.M.F., CARVALHO, P., JARDIM, R., MELO, I., OLIVEIRA, P., SÉRGIO, C., SERRANO, A.R.M. & VIEIRA, P. (eds.). A list of the terrestrial fungi, flora and fauna of Madeira and Selvagens archipelagos. pp. 157-207, Direcção Regional do Ambiente da Madeira and Universidade dos Açores, Funchal and Angra do Heroísmo.         [ Links ]

LOWE, R.T., 1856. Species plantarum Maderensium quaedam novae, vel hactenus ineditae, breviter descriptae. Hooker's Journal of Botany and Kew Garden Miscellany 8: 289-302.         [ Links ]

LOWE, R.T., 1862. A Manual Flora of Madeira and the Adjacent Islands of Porto Santo and the Desertas. 1(2): 113-182. London, John van Voorst.         [ Links ]

MASFERRER Y ARQUIMBAU, R., 1880. Recuerdos botánicos de Tenerife. Datos para el estudio de la flora canaria. Anales de la Sociedad Española de Historia Natural 10: 139-230.         [ Links ]

MENEZES, C.A., 1914. Flora do Archipelago da Madeira (Phanerogamicas e Cryptogamicas Vasculares). Funchal. Typ. Bazar do Povo.         [ Links ]

PICKERING, C.H.C., 1962. A Check-List of the Flowering Plants and Ferns of the Island of Porto Santo (Archipelago of Madeira). Boletim do Museu Municipal do Funchal 15(53): 33-60.         [ Links ]

SANDRAL, G., REMIZOWA, M.V., SOKOLOFF, D.D., 2006. A taxonomy survey of Lotus section Pedrosia (Leguminosae, Loteae). Wulfenia 13: 97-192.         [ Links ]

TURLAND, N.J., 1994. Lotus L. In: Press, J.R. & Short, M.J. (eds.) Flora of Madeira pp.184-189. HMSO. London.         [ Links ]

VIEIRA, R., 1992., Flora da Madeira. O Interesse das Plantas Endémicas Macaronésicas. Serviço Nacional de Parques, Reservas e Conservação da Natureza. Lisboa.         [ Links ]