Massonia dentata Mart.

Martínez-Azorín, Mario, Clark, Vincent Ralph, Pinter, Michael, Dold, Anthony P., Crespo, Manuel B., Barker, Nigel P., Pfosser, Martin & Wetschnig, Wolfgang, 2014, Massonia dentata (Asparagaceae, Scilloideae), a new species from the Nuweveldberge, and typification of the Sneeuberg endemic M. calvata (southern Great Escarpment, South Africa), Phytotaxa 175 (4), pp. 201-215 : 203-212

publication ID	https://doi.org/ 10.11646/phytotaxa.175.4.2
persistent identifier	https://treatment.plazi.org/id/2031878C-FFC5-FFA6-CEA2-38B97916FEC3
treatment provided by	Felipe
scientific name	Massonia dentata Mart.
status	sp. nov.

Treatment

Massonia dentata Mart. View in CoL -Azorín, V.R.Clark, M.Pinter, M.B.Crespo & Wetschnig, sp. nov. ( Figs. 2–8 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 )

Ab M. calvata et M. echinata similis, sed eis et omnibus speciebus generis facile distinguitur et precipue differt segmentis perianticis bracteisque dentatis; foliis semper ad margines ciliis inequalibus munitis atque supra 80−230 pustulis (ca. 0.5 mm diametro) pro cm 2 obsitis quae minutae sunt et trichomate 100−300 µm longo, suberecto, incrassato, anguste conico ferens; filamentis insuper tubo periantico brevissime connatis (minus quam 1 mm long.).

Type:— SOUTH AFRICA. Western Cape, Beaufort West (3222AB): Nuweveldberge, ca. 20 km NW Beaufort West, Farm Grootvlei 193, ex hort. in Grahamstown on 15 May 2010, V.R. Clark & R. Cerros 471b (holotype: GRA!; isotypes: ABH!, GZU!) .

Herbaceous perennial plant. Bulb ovoid, 15−18 × 14−16 mm, inner scales fleshy and white, outer tunics papery and brownish. Leaves 2, deciduous, opposite, spreading and appressed to the ground, synanthous, (2.5−)3−6(−6.5) × (2−)2.5−4.5(−5) cm, ovoid to suborbicular with acute to obtuse apex, with a short apiculum 0.5−1 mm long, narrowed into a petiole 10−15 mm long that clasps the peduncle and the inflorescence, green on both sides, all leaves (from first year to mature plants) with 80−230 emergences/cm 2 and ca. 0.5 mm in diameter only present on the adaxial side, which bear a thickened, suberect to declinate, narrowly conical trichome on top, 100−300 µm long, sometimes bearing 2−3 trichomes when some emergences are placed together, with a narrow membranous margin of 0.2−0.3 mm wide bearing minute papillae on the adaxial side, and short and much longer hairs placed together on the edge. Inflorescence a dense, subcapitate raceme, 1−3 cm long, with (7−)9−16(−20) flowers, shortly overtopping ground level. Bracts membranous, green with a purplish flush and purplish margins in the upper half and white below, translucent after flowering, glabrous with distinctly dentate and denticulate margins, acuminate; lower bracts obovate, 14−17 × 8−10 mm; upper bracts narrowly obovate, 13−16 × 6−10 mm. Pedicels of flowers 2−6 mm long. Flowers tubular. Perigone white, free segments (6−)7−8(−9) × 1.5–2 mm, toothed, greenish at the tip and in the middle longitudinally, first straight and erect, later spreading and finally reflexed and infolded at the base at anthesis, but not strongly rolled in. Perigone-filaments tube 9−13 × 2−4 mm, cylindrical and slightly widening at the upper portion, white. Filaments white, (6−) 7–9 mm long, rather fleshy and thickened, suberect to spreading, straight, attenuate, shortly connate at the base for less than 1 mm above the perigone segments, with an hexagonal mouth of the tube with slightly convex sides; anthers 2−2.5 mm long when closed, oblong, dark blue, dorsifixed, with dark blue pollen. Gynoecium cenocarpoussyncarpous. Ovary narrowly oblong, green, 4–5 × 1–1.5 mm, gradually tapering into the style. Style white with purple tip, thickened, gradually tapering to the apex, 15−17 mm long at anthesis, ending about at the same level than the stamens or shortly overtopping them. Capsule and seeds unknown ( Figs. 2–8 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 ).

Etymology: —Named after the toothed margins of the perigone segments and bracts, a character unknown in any other species of Massonia ; (dentatus, -a, -um = toothed) ( Fig. 5–7 View FIGURE 5 View FIGURE 6 View FIGURE 7 ).

Biology: —Leaves are found in March in wild populations. Massonia dentata flowers in May in cultivation in Grahamstown, South Africa.

Habitat: — Massonia dentata is confined to the summit plateau of the eastern Nuweveldberge, between 1500 and 1800 m. It occurs in dolerite rock crevices at the base of cliffs, and in rocky doleritic soils alongside seasonal streams. The vegetation of the eastern Nuweveldberge at these higher elevations is a blend of marginal grassland (forming part of Mucina & Rutherford’s 2006 Karoo Escarpment Grassland), Upper Karoo Hardeveld (Nama-Karoo Biome; Mucina & Rutherford 2006), and an unclassified ‘Renosterveld’- type of montane shrubland dominated by Elytropappus rhinocerotis Lessing (1832: 344) ( Fig. 9 View FIGURE 9 ). This region shows a seasonal rainfall mainly in autumn and summer peaking in March, with a mean of annual rainfall of 250−350 mm ( Mucina & Rutherford 2006).

Distribution: —Known from two localities 10 km apart in the far eastern Nuweveldberge, Western Cape Province, South Africa. This distribution includes the highest elevations of the Karoo National Park ( Fig. 10 View FIGURE 10 ). It is only the seventh endemic plant species known from the drought-prone Nuweveldberge, after the six listed by Clark et al. (2011a). It is worth mentioning that Van der Merwe (2002) cited the collection “3320 (Montagu): Mountainview, Karoo National Park, (-BA), Bruyns 3358 (BOL!)” under Massonia pustulata Jacq. (1791: 177) . Although it seems that the quarter degree given was an error, the locality in the Karoo National Park, and the fact that the specimen was included in M. pustulata (therefore most probably bearing pustules) points out that it could represent the third known locality of Massonia dentata . As the Massonia specimens kept at BOL are currently on loan, we were not able to study that specimen and it should be considered in future works.

Taxonomic relationships: — Massonia dentata can be easily distinguished from all other species in the genus by the combination of toothed perigone segments and bracts, leaves in all stages with numerous emergences, each bearing a thickened trichome, and margins with hairs of different lengths ( Figs. 2−8 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 ). Its closest known relative appears to be M. calvata , but the latter differs by the leaves in flowering individuals with almost absent or scarce emergences and trichomes, the entire perigone segments and bracts, and the shorter and wider ovary, among other characters ( Table 1, Fig. 1 View FIGURE 1 ). Massonia echinata sensu Müller-Doblies & Müller-Doblies (1997) differs from M. dentata by the usually larger leaves, with scarce small pustules, the minutely denticulate leaf margin, the entire perigone segments and bracts, the reflexed, infolded and spirally curled in perigone segments, the mouth of the perigone-filaments tube with 6 gibbosities and its different distribution (see Wetschnig et al. 2012) ( Table 2). Furthermore, remarkable differences exist in the distribution of the cited taxa. Massonia echinata appears to be endemic to a small area in the surroundings of Nieuwoudtville and the Vanrhynspas, whilst M. dentata is only known from the eastern Nuweveldberge, being more than 300 km apart. Finally, according to our data Massonia calvata is endemic to the Sneeuberge, a different mountain range located ca. 150 km to the east of the Nuweveldberge ( Fig. 10 View FIGURE 10 ). As explained before, the collection Bruyns 3358 (BOL!) was identified as Massonia pustulata , however, the latter species clearly differs from M. dentata by distinct characters ( Wetschnig et al. 2012).

Additional specimens studied (paratypes): — South Africa. Western Cape: Beaufort West (3222AB): Nuweveldberge, ca. 20 km NW Beaufort West, Farm Grootvlei 193, alt. 1720 m, 08 March 2008, V.R. Clark & R. Cerros 471a ( GRA!, NBG!); Beaufort West (3222BA): Nuweveldberge, Karoo National Park , 12 March 2008, alt. 1670 m, SANParks, V.R. Clark & R. Cerros 591 ( GRA!, NBG!) .