Menonvillea nordenskjoeldii (Dusén) Rollins (1955: 21)

Salariato, Diego L., Zuloaga, Fernando O. & Al-Shehbaz, Ihsan A., 2014, A revision of the genus Menonvillea (Cremolobeae, Brassicaceae), Phytotaxa 162 (5), pp. 241-298 : 264-265

6. Menonvillea nordenskjoeldii (Dusén) Rollins (1955: 21) . Hexaptera nordenskjoeldii Dusén (1900: 172) . Hexaptera cuneata Gillies & Hook. var. nordenskjoeldii (Dusén) Gilg & Muschler (1909: 443) . TYPE:— CHILE. [Región del Aysén]. Cerro Contreras, ca. 900 m, O. Nordenskjöld s.n. (holotype UPS 2267-32!).

Perennials with thick, deep, fleshy, branched caudex and often underground, prostrate, rhizome-like stems. Stems (3.5−)5−15(−30) cm, fleshy, erect to subdecumbent, usually unbranched above, with numerous foliar scars, sparsely to densely pubescent with simple, flat, crisped or more commonly twisted, spreading trichomes 1−2(−3) mm long, rarely glabrous or glabrescent. Leaves cauline, subsessile; blade cuneate, deeply 3−5(−7)-lobed at apex, (6−)8−18(−25) × (3−)5−10(−13) mm, densely pubescent to glabrescent or rarely glabrous, base cuneate, differentiated or not into petiole and blade, margin entire, lobes acute at apex. Racemes terminal, ebracteate or less frequently bracteate proximally, corymbose, densely flowered, not elongated in fruit, borne only slightly above adjacent leaves, (1.5−) 2−4 cm long; rachis straight, usually pubescent or glabrescent; fruiting pedicels ascending to divaricate, usually straight, (8−)10−15(−20) mm long, glabrous or pubescent. Sepals oblong, (3−)4−5 × 1.5−2(− 2.5) mm, pubescent or glabrous, erect, not saccate, usually persistent, margin scarious; petals white, sometimes purplish at base, spatulate to broadly so, (5−)6−8(−9) × (1.5−)2.5−3.5(−4.5) mm, clawed, not papillate at base, apex rounded; stamens tetradynamous; filaments free, erect, dilated and not papillate at base, 3−4(−4.5) mm long; anthers narrowly oblong, 1−1.5 mm long; nectar glands confluent, ringlike, subtending bases of all filaments. Fruits subglobose, glabrous or rarely pubescent; valves 3-winged, conspicuously veined, 5−8 mm in diam.; wings (1−)1.5−2(−2.3) mm wide; gynophore (0.5−)1−2(−3) mm long; style 1−2(−2.8) mm long; stigma slightly decurrent. Seeds ovate, 2.8−3.2 × 1.8−2 mm, wingless, flattened; cotyledons accumbent.

Distribution and habitat:— Menonvillea nordenskjoeldii is the southernmost species of the genus and restricted to Patagonian Argentina (Chubut, Río Negro and Santa Cruz) and southern Chile (IX Aysén and XII Magallanes). It grows on rocky soils at the limits of vegetation between 500−2100 m ( Fig. 12F ).

Phenology:—Flowers mainly from December to March, although Dollenz 1226 (HIP) was collected on April.

Taxonomic notes:— Menonvillea nordenskjoeldii is morphologically related to M. cuneata and M. rigida , from both of which it is easily distinguished by having leaves deeply 3−5(−7)-lobed (vs. 3-dentate/lobed), spreading, flat, crisped or twisted trichomes to 3 mm long (vs. straight, retrorse or spreading trichomes to 1(−1.2) mm long), and persistent (vs. caducous) sepals. Molecular phylogenies based on nuclear and chloroplasl data indicate that M. nordenskjoeldii is most closely related to M. rigida .

Representative Specimens:— ARGENTINA. Chubut: Depto. Futaleufú, Parque Nac. Los Alerces , cordón Situación, February 1944, Pérez Moreau s.n. ( BA 49542 , BAA) . Río Negro: Depto. San Carlos de Bariloche , Cerro Colorado, 16 February 1942, Neumeyer 597 ( SI) . Santa Cruz: Depto. Güer Aike , Cerro Pinaculo, January 1977, Boelcke 626 ( SI) ; Depto. Lago Argentino, El Calafate, Estancia Anita, Cerro Huiliche , 2º laberinto, 14 December 2001, Guerrido & Fernández 434 ( LP, SI) ; Depto. Río Chico , Cerro Corona. Ea. "El Rincón", Lago Belgrano, 23 December 1940, Spegazzini 178 ( BAB) . CHILE. XI Aysén: Prov. Capitán Prat, Com. O’Higgins, Villa O'Higgins, Cuenca del Río Mosco , 24 March 2003, García 131 ( CONC) . XII Magallanes: Prov. Magallanes, Com. Punta Arenas , Isla Riesco, Fiordo Fanny, 2 April 1982, Dollenz 1226 ( HIP) ; Prov. Última Esperanza, Com. Torres del Paine, Sierra de Los Baguales , Estancia la Cumbre , Cerro sin nombre, 7 January 1987, Landero 732 ( CONC) .

Figures

FIGURE 12. Distribution of species of Menonvillea sect. Cuneata. A, M. cicatricosa. B, M. comberi. C, M. cuneata. D, M. frigida. E, M. macrocarpa. F. M. nordenskjoeldii. G. M. patagonica. H, M. rigida. I, M. spathulata. J, M. virens.