L . Carvalho ( Campanulaceae ) , a new species from the Madeira Archipelago ( Portugal )

Menezes de Sequeira, M., Jardim, R., Silva, M. & Carvalho, L. 2007. Musschia isambertoi M. Seq., R. Jardim, M. Silva & L. Carvalho (Campanulaceae), a new species from the Madeira Archipelago (Portugal). Anales Jard. Bot. Madrid 64(2): 135-146. A new species of Musschia Dumort. (Campanulaceae), endemic from Madeira Archipelago (Portugal), is described as Musschia isambertoi M. Seq., R. Jardim, M. Silva & L. Carvalho. Both vegetative and reproductive structures have been studied and are remarkably distinct from the recognized species [M. aurea (L. f.) Dumort. and M. wollastonii Lowe]. A full description and a diagnosis are included as well as line art, color drawings and pictures. Diagnostic characters are discussed and compared with those of the closely related species. The new species has a very restricted distribution occurring in two isolated populations in the Deserta Grande Island (Madeira Archipelago, Portugal). Nomenclatural aspects on the genus Musschia Dumort. are discussed and a diagnostic key for the species is also included.


Introduction
The Madeira archipelago is composed of three groups of islands, Porto Santo with about 20 My., Madeira and Desertas more recent and sharing a common geological origin.The Madeira island is situated between 32°38' and 32°52'N and 16°39' and 17°16'W, at approximately 600 km northwest of the Western African coast.It is a within-plate volcanic island the tip of a stratovolcano about 6 km high.The emerged part of the island dates back to Post-Miocene times, < 5.6 My. (Ribeiro & al., 2005), and the more recent volcanic activity took place 6000-7000 years B.P. (Geldmacher & al., 2000).The Madeira island has 737 km 2 of surface.The maximum altitude is at Pico Ruivo, reaching 1861 m above sea level.
To the southeast the Madeira archipelago is continued by the Desertas sub-archipelago composed by three small islands.The northernmost is Ilhéu Chão (ca.0.5 km 2 ), which is also the smallest with only 100 m above sea level.The largest, Deserta Grande (ca. 10 km 2 ), has a maximum altitude of 442 m above sea level.Finally Bugio (ca. 3 km 2 ), the southern island has a maximum altitude of 348 m above sea level (Press & Short, 1994).
As stated, the first species was described previously by Linnaeus f. (1782) as Campanula aurea L. f. as " Campanula (aurea)  The early (1777-1830) references to Musschia (as Campanula L.) are all presumably based on seeds taken to the mainland from Madeira by Masson but also (possibly) by other authors.Ker Gawler (1815) not only includes a beautiful drawing of Musschia aurea (as Campanula aurea), but also a full and detailed description of this species.The seeds, as stated by Ker Gawler (op.cit.), were taken to England by Masson in 1777, previous to the description by Linnaeus f. (1782).The list of plants collected in Madeira by Francis Masson, including notes, was never published.Two cultivated species at Kew Gardens are referred by Ker Gawler (op.cit.) but the second species corresponds to Campanula lobeliodes L. f. [later included in the genus Wahlenbergia as W. lobelioides (L.f.) Link].Musschia aurea had already been referred by Aiton (1789) as Campanula aurea L. f. cultivated in Kew Gardens.The early history of Madeira Campanulaceae, as with many other species and families, seems to have an origin in Masson's collections, lists and cultivations.
Ker Gawler (1815) refers to Campanula aurea with two varieties, α latifolia, which he refers to an icon in Ventenat (1805), and β angustifolia, with no description other than a reference to Jacquin (1804) Plantarum Rariorum Horti Caesari Schoenbrunnensis Descriptiones et Icones.The line drawing in Jacquin (op.cit) comes with no description or table but clearly corresponds to a narrow leaved plant (Fig. 1).The publi- cation Jardin de Malmaison by Ventenat (op. cit.) includes drawings by Redouté.
Later, De Candolle (1830, 1838) refers to Musschia aurea and to the unpublished notes by Masson to cite the β angustifolia (which he describes as foliis angustioribus).However, Dumortier (1823) had already proposed the name and given a description of these narrow leaved plants as Musschia angustifolia Dumort.This name is presumably based on Ker Gawler (1815, as C. aurea var.angustifolia) while Dumortier makes no reference to previous descriptions or icons of this narrow leaved variety, he does, however, distinguish the habitat of α (Musschia aurea) "in littore" and β (Musschia angustifolia) "In interioribus insulae", suggesting that he based his notes on Ker Gawler (op.cit.) which states the same geographic pattern based on Masson's unpublished notes.
Dumortier ( 1823) is in fact the first to give a description and to name correctly the narrow leaved Musschia aurea plants.If no plants were to be found in order to name a lectotype, it would be advisable to elect the icon published by Jacquin (1804).

Material and Methods
Plants belonging to the new taxon were collected during spring of 2006 in the Desertas islands and deposited at MA (typus).Studied plants of the genus Musschia were examined from MADJ (including MADS) and MADM.Macroscopic analysis was performed using a binocular microscope Zeiss model SV 11 APO.
The distribution map is based on geographic coordinates of the studied specimens converted to Cartesian coordinates using a local Datum (Porto Santo) and plotted using ArcView GIS 3.1.

Musschia isambertoi
Distribution.Musschia isambertoi is known from only two populations on the Deserta Grande Island, including the population from Fajã Pequena (Fig. 4).Musschia aurea is also present (and is much more common) on this island.
Habitat.Musschia isambertoi seems to grow preferably at almost sea level at damps, the extraordinary habit of this plant immediately strikes the observer, in fact when in flower, it is the largest macro-  2006)) refer to biological invasions as possible disrupters of mutualism and consequences on conservation, this seems to be the case in the Deserta Grande where goats but also rabbits were responsible for massive vegetation destruction.Goat and rabbit eradication was initiated in 1996.Rabbits were totally eradicated and the reduction of goat numbers was followed by a rapid recovery of the flora.The recent increase in goat population seems to be driving most endemics to a population decrease, both in number and in density.On Madeira, the competition by invading plants, such as Opuntia tuna (L.) Mill., may also cause a disruption of mutualism rela- tions between Lacerta dugesii dugesii and Musschia aurea.Future works on the biological relations between Lacerta dugesii dugesii and Musschia aurea as well as M. isambertoi and the Desertas endemic Lacerta dugesii mauli should enlighten us regarding both mutualism relationships and conservation aspects.Flower colours and inflorescence typical structure are the most important morphological traits that may have evolved from mutualism with reptile pollinators as a co-evolutionary process.
Phenology.Data on flowering is scarce however it seems to flower from May to June.
Conservation status.Due to the scarce number of populations and the reduced occupancy and occurrence area as defined by IUCN (2001), and also due to the grazing effects through the introduction of goats, this new species should be considered as Critically Endangered (CR, C2a(i,ii); D).
Musschia isambertoi, a new species from the Madeira Archipelago herb of the Desertas.It does not share a common ecology with Musschia aurea on the Desertas as on Madeira, where M. aurea is a chasmophyte.Several individuals of the Desertas endemic lizard Lacerta dugesii mauli Mertens, 1938, were seen pollinating the flowers of Musschia isambertoi (Fig. 5 b, c).Elvers (1978) refers to lizard pollination in Madeiran plants of Musschia aurea and Olesen & Valido (2003) further stress the role of lizards as pollinators and seed dispersers on islands, referring to Musschia aurea and Lacerta dugesii Milne-Edwards, 1829.Recently Traveset & Richardson (