Menonvillea orbiculata Philippi (1860: 9)

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 : 283

19. Menonvillea orbiculata Philippi (1860: 9) . Type:— CHILE. [Región de Atacama]. Caldera , R. A . Philippi s.n. [lectotype designated by Al-Shehbaz et al. (2011: 285), SGO 49155!; isolectotype SGO 68274!] .

Menonvillea orbiculata var. perplexa Rollins (1955: 47) . Type:— CHILE. [Región de Antofagasta]. Prov. Antofagasta, Com. Taltal, Cerro Yumbes, vicinity of Paposo , 25°0′S, 8 December 1925, I. M. Johnston 5552 (holotype GH!; isotypes K!, S!) .

Menonvillea alata Rollins (1955: 51) . Type:— Chile. [Región de Atacama]. Prov. Copiapó, Copiapó, Quebrada de Chanchoquin , September 1885, E. E. Gigoux s.n. (holotype GH!) .

Perennials, rarely annuals or biennials, usually suffruticose. Stems (6−)8−37(−60) cm, usually several from base, gyrose or not, densely floccose to glabrescent, usually floccose at leaf axils with simple or arachnoid trichomes to 0.5 mm long. Leaves basal and cauline, sessile; blade terete, pectinate or undivided, linear or with linear segments, fleshy, 1−5 cm × 0.7−2.5 mm, glabrous or sparsely pubescent. Racemes terminal or less frequently axillary, ebracteate, corymbose, elongated considerably in fruit, 5−20 cm long; rachis glabrous to glabrescent, straight in fruit; fruiting pedicels divaricate, arcuate or rarely straight, stout, 2−4(−5) mm long, pubescent. Sepals oblong, 2.5−4(−4.4) × 1.5−2.3 mm, floccose to glabrescent, erect, not saccate at base, caducous, margin broadly membranous; petals yellow to yellowish green, linear-oblanceolate, 3.5−7(−8) × 0.7−1.2(−1.5) mm, clawed, base sparsely papillate or rarely glabrous; stamens tetradynamous; filaments free, erect, base not dilated, sparsely papillate or glabrous, (3−)3.5−4.5(−5) mm long; anthers oblong, 0.9−1(−1.5) mm long; nectar glands confluent, not or rarely petaloid. Fruits subglobose to slightly longer than broad; valves 2-winged, (2.5−)3.5−5.5(−6) in diam., emarginate at apex and base, dorsal and ventral surfaces each with 2, poorly developed or conspicuous lateral callosities with clavate papillae at center; wings (0.5−) 0.8−1.2 mm wide, flat; gynophore 0.5−1(−1.5) mm long; style 1−1.5(−2) mm long. Seeds ovate, 1.5−2.4 × 1.1−1.6 mm; cotyledons incumbent.

Distribution and habitat:— Menonvillea orbiculata is endemic to northern Chile in regions II (Antofagasta), III (Atacama) and IV (Coquimbo) at elevations between sea level and 800 m. It grows among rocks, gravel, and on sand in shelter of large rocks ( Fig. 13I ).

Phenology:— Flowers between September and November and rarely, Ricardi 5468 (CONC), in February.

Taxonomic notes:— Rollins (1955) distinguished Menonvillea orbiculata var. perplexa from var. orbiculata by having ovoid to oblong (vs. subglobose) fruits and non-petaloid (vs. petaloid) nectar glands. Fruit shape and size are so variable in the species that all of the above variants can be found on the same plant. Furthermore, the nectar glands in the species are not petaloid, and only occasionally one finds plants with subpetaloid glands. Therefore, var. perplexa does not merit recognition.

The type specimen of Menonvillea alata differs from typical plants of M. orbiculata in being a non-floccose annual, but both taxa are indistinguishable in others characters. Although plants of M. orbiculata are perennial, they usually flower in the first year and sometimes they are glabrescent except in leaf axils, just as in the type of M. alata , which lacks the fully mature fruits.

Representative Specimens:— CHILE. III Atacama: Prov. Copiapó, Com. Caldera, 5 Km al sur de Obispito, camino Caldera-Chañaral , 10 February 1968, Ricardi 5468 ( BAB, CONC, SI); Prov. Huasco, Com. Freirina, Quebrada El Morado 1 km SO de la junta del camino Carrizalillo-El Morado, 23 October 1971, Marticorena at al. 1784 ( CONC). IV Coquimbo: Prov. Elqui, Com. La Higuera , Los Choros, fondo de quebrada seco, 17 November 1961, Jiles 3950 ( CONC); Prov. Limarí, Com. Ovalle, Fray Jorge, 15 September 1947, Ibañez & Kuschel s.n. ( SGO 130633 ) .

Figures

FIGURE 13. Distribution of species of Menonvillea sect. Menonvillea. A, M. chilensis. B, M. constitutionis. C, M. filifolia. D, M. flexuosa. E, M. linearis. F. M. litoralis. G. M. marticorenae. H, M. minima. I, M. orbiculata. J, M. pinnatifida. K, M. purpurea.