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Isoëtes todaroana (Isoëtaceae, Lycopodiophyta), a New Species from Sicily (Italy) PDF

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New todaroana Isoetes (Isoetaceae, Lycopodiophyta), a from Species Sicily (Italy) Angelo Troia* and Francesco M. Raimondo Dipartimento di Scienze Botaniche dell'Universita, via Archirafi 38, 1-90123 Palermo, Italy Four species of Isoetes have been previously reported from Sicily (Troia, 2005): Isoetes histrix Bory, sicula Tod. [= subinermis & (Bory) Cesca /. /. =? gymnocarpa Peruzzi, (Gennari) A. Braun], velata A. Braun. and 7. duriei I. I. Bory. All of these grow on seasonally wet, siliceous except soils, for velata /. which colonizes temporary ponds. Over the last ten years, field, herbarium, and laboratory studies have been conducted by one on Romeo of us the genus Isoetes and (e.g., et 2000; Troia al., As Bellini, 2001; Troia, 2005). part of these studies, a population was oi Isoetes located wetland Mazara in a near del Vallo, Western Sicily. Closer inspection of the specimens showed they that differed in several aspects from the other species occurring on the island. Analyses of living and dried plants confirmed that this population represents a unique and previously undescribed species of which named Isoetes, is here and described. For description and nomenclature of megaspores and microspores we followed Hickey and Musselman (1986) (2003), respectively. Isoetes todaroana Troia & Raimondo, TYPE.— nov. ITALY. sp. Sicily: contrada "Critazzo" near Mazara del Vallo, 37 41'07"N, 12 37'05"E, 60 ca. m 10 Apr. Angelo a.s.L, 2009, Troia (holotype: PAL; PAL, isotypes: FI). 1-10. Figs. Herba perennis amphibia, emergens aut submersa. Cormus trilobus, radicibus dichotomis. 15-30 cm Folia (-40), erecta vel patentia, 3-6 (-14) longa, inferne brevi tractu anguste alato-membranacea, usque 3-4 mm, basi in mm medio Duae magnae circa lacunae 1-3 1 lata. et fasciculi fibrarum periphaerici (collenchymatosi) in trasversali sectione. Stomata 37- elliptica, ^m 24-32 70 ^im longa, tantum Velum lata, in facie abaxiali obvia. sporangium TROIA RAIMONDO: TODAROANA, A NEW FROM & ISOETES SPECIES SICILY 1-3. Morphologic! Figs. on the left partially cove: obtegens. Ligula membranacea, Labium lanceolata, basi auriculata. breve. Squamae paucae, coriaceae, nigrescentes, lobis lateralibus rotundatis dente et medio aciculari. Macrosporae candidae, sphaeroideae, 420-460 ^m, annulo horizontali cinctae, hemispherio superiore undique tricostatae, tuberculatae. Microsporae hyeme ovatae, ca. 25 ^im longae, aculeatae. Habitat in humidis inundatis. Plants amphibious, emergent or submerged in temporary ponds, losing their summer Stem leaves in the dry season. (corm) with dichotomous trilobate, cm roots. Leaves 15-30{-40), patent to erect, narrowly lanceolate, 3-6 (-14) mm mm 3-4 wide wide long, at base, ca. 1 at mid-length. Alae proximally mm hyaline or transluscent, ca.l wide the sporangium, gradually narrowing at Subula distally. semiterete, adaxially abaxially convex. Leaf epidermis flat, with cuticular ornamentation, "cuticular pegs" (sensu Prada and Rolleri, 2005, = "cuilas cuticulares" sensu and Rolleri Prada, 2007) well developed, evident as continuous longitudinal Stomatal complexes 37- ridges. rows, in elliptic, nm 24-32 70 long, |im wide, confined to the abaxial surface. Hypodermal coUenchymatous bands one to three, the two marginal bands sometimes absent. Air chambers two, with translacunar diaphragms. Velum complete. mm Ligule membranaceous, ca. 1 long, broadly lanceolate, auriculate at base. TROIA & RAIMONDO: ISOETES TODAROANA, A NEW FROM SPECIES SICILY mm SEM ma Figs. 7-10. images of todaroi megaspores and microspores. Proximal view /. 7. of megaspore. view Equatorial of megas] Megaspore 8. pore. 9. (detail of a single tubercle). 10. Distal new Etymology.— This species dedicated is to the Sicilian botanist Agostino Todaro (1818-1892), in recognition of his contribution to the pteridological of flora Sicily. Ecology.—The type temporary wetland locality is a that dries out during the summer. remnant a of a wider wetland has been "reclaimed" and It is that converted to farming land that surrounds and encloses the type The locality. natural vegetation, although altered, well represented with mosaic is a of communities, with species such as Bolboschoenus maritimus (L.) Palla, Eleocharis palustris (L.) Roem. & Schult., Scirpus cernuus Vahl, Mentha pulegium Oenantbe Lythrum Tamarix Homulea The L., sp., sp., sp., sp., etc. wetland hosts the last remnants of a peculiar freshwater invertebrate fauna; a preliminary investigation has example, led, for to the discovery of a small population of the notostracan Lepidurus apus lubbocki (Crustacea), a "living was fossil" that considered extinct in Sicily Marrone, pers. comm.). (F. The wetland on exists a peculiar geological substrate of calcareous sandstones with on a thin layer of clays top (hence the name, local "Critazzo", which pH in Sicilian dialect refers to clays). The soil around the Isoetes (determined electrometrically with two replicates from 20 of and g soil measured in distilled water with a dilution ratio of 1: 2.5) was found to be AMERICAN FERN VOLUME NUMBER JOURNAL: 99 4 (2009) As we know, basic, 8.5-8.9. far as the other species occurring in Sicily grow on consistently acid soils, so that this although geologically site, complex, unusual, is a fact that deserves further investigations. known Distribution.—/soefes todaroana only so far from the locus classicus. is in an area of about 200 X 100 m. possible that other populations may be It is found and in the future, in Sicily elsewhere in the Mediterranean area. — The known Conservation Status. single population threatened by farming is human and other activities (waste dumping, land reclamation, summer fires, On "lUCN Red and etc.). the basis of the current List Categories Criteria" (lUCN, 2001], the species rated "Critically Endangered" [CR is Blab(iii)]. Urgent measures needed are to protect the considering that site; is it practically unexplored, possible that other rare or endangered species are it is present, in addition to Isoetes todaroana and Lepidurus apus lubbocki already mentioned. However, and clear that a strategic area for migrating birds it is it is communities hosts that can be referred to the habitat "Mediterranean it temporary pond", considered a "priority" habitat by the Council of the European Communities 92/43/EEC Our Directive. proposal include the to is Community site, currently not protected, inside the adjacent "Site of Interest" code ITA010014, and established to protect habitat species according to the mentioned made Directive. Since this inclusion will not be in a short time and we will not automatically guarantee the protection of species and habitats, also suggest considering other actions agreements with the owners, (e.g., territory planning land purchase) soon restrictions, as as possible. — Taxonomic Observations. The shape and of the scales, particularly the presence of only two leaf air chambers rather than four as in other species all of the genus (Rolleri and Prada, 2007), are the main differentiating characters of this species. Its systematic relationships are difficult to assess merely on the basis of anatomy and morphology, owing and convergent to parallel morphological evolution in the genus (Hickey, 1986; Hoot et al, 2006; Bolin The et al, 2008). presence of scales, sometimes transitioning into phyllopodia, and coUenchymatous between and strands suggests a link this species the Mediterranean and megaspore "terrestrial" taxa, the ornamentation, in particular, vaguely suggests a connection with histrix and sicula. However, /. /. shown as by Bolin et al. (2008), the latter two species, although morpholog- On ically similar, are not immediately related. the other hand, the fibrillose megaspore background surface suggests a relationship with other (Fig. 9) amphibious species, the Isoetes velata. e.g., new Further studies are in progress to add to the knowledge of the species and shed on light relationships. its TROIA & RAIMONDO: ISOETES TODAROANA, A NEW FROM SPECIES SICILY

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