Massonia gypsicola - description

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Massonia gypsicola - description

Postby friendsadmin » Sun Jun 04, 2017 8:06 pm

From Massonia gypsicola (Asparagaceae, Scilloideae), a new species from the
Knersvlakte in South Africa

Massonia gypsicola Mart.-Azorín, M.Pinter, M.B.Crespo, M.A.Alonso & Wetschnig, sp. nov.
Species notabilis combinatione propria characterum ab ceteris speciebus Massoniae bene distincta. Folia pustulata pustulis leviter asymmetricis conicis vel hemisphaericis 0.4–0.8 mm diametro plus minusve numerosis (15–40) obsita, quae ad apicem papilla late vel anguste conica et valida 0.1–0.8 mm long. munitas. Flores albidis, ad apicem segmentorum fascia longitudinali viridi instructis; tubo brevi (ad 7 mm long.) et strictissimo, ad faucem egibboso, longitudine ovarium valde occultante; et segmentis perigonii 5–8 × 1.5–2 mm, reflexis sed non revolutis, a basi vix sigmoideo-curvatis. Antherae statu clauso ca. 2 × 1 mm, luteolae; polline luteo subconcoloro. Ovarium conicum vel suboblongum, ca. 3–4 × 1.5–2 mm, in stylo gradualiter desinente. Semina 1.6–2.0 × 1.5–1.8 mm, globosa, nigra, laevia.

Type:—SOUTH AFRICA. Western Cape. Vanrhynsdorp (3118): Knersvlakte, ca. 4 km SW of N7 on the gravel road parallel to the railway, farm Quaggas Kop 215 (-BC), crevices and shallow soil on gypcrete outcrops, 135 m elevation, 14 November 2016 ex hort. in Graz (Austria), M. Martínez-Azorín, M. Pinter, M.B. Crespo & M.A. Alonso MMA1298 (holotype GRA!; isotypes ABH!, GZU!).

Deciduous geophyte. Bulb ovoid to subglobose, 1.4–4.3 × 0.9–4 cm, hypogeal, with white, fleshy bulb scales covered by pale brown, papery or slightly leathery outer tunics. Leaves 2, synanthous, opposite, appressed to the ground, ovoid, with an acute apex and a short apicule about 2–3 mm long, limb 2.5–9 × 1.5–5 cm (up to 15 cm long in cultivation), with narrow, membranous, entire to minutely denticulate margins; adaxial side green, with 15–40 slightly asymmetrical, conical to hemisphaerical, emergences per cm2, which are 0.4–0.8 mm in diameter, with a conical to elongated and slightly deflexed, thickened, smooth trichome on top, 0.1–0.8 mm long; abaxial side smooth, green; petiole 0.5–2.5 cm long. Inflorescence a dense, subcapitate raceme, up to 2–3 cm long, with 10–25 flowers, shortly overtopping ground level. Bracts narrowly obovate, attenuate at the apex, 15–25 × 5–9 mm, green in the upper half with white membranous margins and base, glabrous, entire. Pedicels at anthesis 8–16 mm long. Flowers pentacyclic, trimerous. Perigone pure white; tepals 6, free segments 5–8 × 1.5–2 mm, entire, with a short greenish central band at the tip, straight and erect in bud, reflexed with a sigmoid curve at the base but not distinctly inrolled at anthesis; perigone-filaments tube 6–7 × 2–3 mm, narrowly cylindrical, not widening in the upper portion, with a circular mouth with no gibbosities, the ovary included in the tube and not visible. Stamens 6, filaments long-attenuate, spreading at anthesis, slightly arcuate, white, 10–15 mm long, shortly connate at the base for ca. 0.5 mm above the perigone segments; anthers oblong, pale yellow, ca. 2 × 1 mm when closed, dorsifixed, with yellow pollen. Gynoecium obclavate, compound, tricarpellar, with axile placentation. Ovary superior, conical to suboblong, white to pale green with a purple tinge, 3–4 × 1.5–2 mm, gradually tapering to the style, with 12–14 ovules per locule. Style white, erect, 10–14 mm long at anthesis, narrowly conical, gradually tapering from the ovary to the acute, simple stigma. Capsule ovate in lateral view, trigonous with blunt edges in apical view, 7–12 × 3–7 mm. Seeds globose, black, 1.6–2.0 × 1.5–1.8 mm,

Etymology:—The specific epithet (gypsicola: growing in gypsum substrate) refers to the distinct and unique habitat of this new species; this is so far the only taxon in Massonia occurring on gypcrete outcrops.

Phenology:—Massonia gypsicola flowers between May and July in the wild and fruits appear from July to August. In cultivation in Graz (Austria) it flowers around November and fruits appear in late December.

Habitat:—Massonia gypsicola occurs in crevices and shallow soil on eroding outcrops of gypcrete (deep weathering gypsum rich duripans; see also Francis 2008), rich in calcium sulphate, from 100 to 150 m of elevation. The surrounding vegetation is classified as Knersvlakte Quartz Vygieveld (SKk3) and Central Knersvlakte Vygieveld (SKk2). The region is characterised by winter rainfall peaking from May to August, and dry hot summers, with a mean annual precipitation of 110 mm and rare occurrence of frost (Mucina & Rutherford 2006). Knersvlakte is a worldwide well known area for succulents including many endemic taxa, and this new Massonia species increases the value of this region.

Distribution:—The new species is known to us only from two localities west of N7 in Knersvlakte, and appears to be endemic to this area. Further populations are expected to be found on similar habitats close-by.

Taxonomic relationships:Massonia gypsicola can be easily distinguished by the leaves covered by distinct conical to hemisphaerical emergences that usually bear a distinct trichome on top; white flowers with short and narrow perigone filaments tube; yellow anthers and pollen; and obclavate gynoecium. Its morphologically closest relative appears to be Massonia pseudoechinata Mart.-Azorín, M.Pinter & Wetschnig in Martínez-Azorín et al. , but the latter differs by leaves with scarce to numerous small emergences; flowers with much longer perigone-filaments tube; strongly reflexed and inrolled perigone segments; shorter filaments, the blue anthers and pollen; longer ovary and style; and bigger capsules. Massonia pseudoechinata grows on top of the Bokkeveld Plateau near Nieuwoudtville and the Vanrhyns Pass, at elevations of about 700–800 m a.s.l. and vegetation classified as Bokkeveld Sandstone Fynbos and Nieuwoudtville Shale Renosterveld (Mucina & Rutherford 2006). The general flower morphology of M. gypsicola, especially the obclavate gynoecium, links this species to M. pseudoechinata, M. roggeveldensis Mart.-Azorín, M.Pinter & Wetschnig in Martínez-Azorín et al., M. bakeriana M.Pinter, Mart.-Azorín & Wetschnig in Pinter et al., M. mimetica Mart.-Azorín, M.Pinter, M.B.Crespo & Wetschnig in Martínez-Azorín et al., M. jasminiflora Burch. ex Baker (1870: 390) and related species. However, none of the related species shows the distinct combination of character-states occurring in Massonia gypsicola.

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