Salicornia tegetaria (S.Steffen, Mucina & G.Kadereit) Piirainen & G.Kadereit

Steffen, S., Mucina, L. & Kadereit, G. (2009). Three new species of Sarcocornia (Chenopodiaceae) from South Africa. Kew Bulletin 64: 447. https://doi.org/10.1007/s12225-009-9127-1

Type

South Africa, Western Cape, Vredendal, Papendorp, Olifants R. Estuary, 18°12′15.2″E, 31°41′39.0″S, Steffen & Mucina 250306/03 (holotypus NBG!; isotypus MJG!).

Morphology General Habit

Woody perennial subshrub, prostrate or decumbent, forming dense mats to 20 cm high, main branches prostrate, 1 – 3 (− 6) mm in diam., often slightly thickened and rooting at the nodes, lateral branches often arising in pairs from the nodes

Morphology General

Segments strongly succulent, barrel-shaped to obconical, 7 – 15 mm long, 1 – 4 mm (dried), 2 – 5 mm (fresh) wide, dead cortex adhering to the stems but disintegrating from prostrate main branches, leaf apex not keeled, leaf margin truncate, rarely spreading, segments in herbarium material strongly flattened denoting the stem

Morphology Reproductive morphology Inflorescences

Inflorescences terminal, rarely lateral, spike-like thyrses, 8 – 70 mm long, 2 – 4 mm (dried), 2 – 6 mm (fresh) in diam., tapering in flower and fruit, with 2 – 22 fertile segments

Morphology Reproductive morphology Flowers

Flowers 3 per cyme in a row, 1/2 of the flower covered by the subtending bract, central flower c. 2 mm, slightly longer than the lateral ones, protogynous, perianth tube with 3 lobes, cork-like when mature, adhering to the seed

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 1 – 2, adaxial, anthers c. 1 mm long

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigmas bifid, plumose, spreading

Morphology Reproductive morphology Seeds

Seeds c. 1.3 mm long, 1.1 mm broad, at the edge covered with hairs, hairs adjacent to erect, c. 200 μm long, involute at the apex, testa in the centre ruminate.

Distribution

South Africa, from the Orange River estuary on the West Coast (Namibia/South Africa) in estuaries along the entire Atlantic and Indian Ocean Coasts of South Africa as far east as Durban (KwaZulu-Natal). Also found in Namibia, Namib Desert coast, near Lüderitz and on the southern Mozambique coast, especially in the Maputo Bay and on neighbouring islands.

Ecology

The typical habitat of Sarcocornia tegetaria is sandy estuaries, in particular low intertidal zones subject to regular and long-lasting tidal flooding. Here species-poor salt-marsh communities are formed and S. tegetaria is accompanied only by sub-tidal grasses such as Zostera capensis Setch. (Zosteraceae) and Sporobolus virginicus (L.) Kunth (Poaceae) and scattered populations of Salicornia meyeriana Moss (Chenopodiaceae) complex and various Triglochin L. (Juncaginaceae) species. Sarcocornia tegetaria occurs also in the middle tidal zone, where the salt-marsh communities are more species rich. Frequent accompanying taxa here are various species of Limonium Mill. (Plumbaginaceae), Triglochin and Chenolea diffusa Thunb. (Chenopodiaceae). Mucina et al. (2006c) classify this vegetation as Arid Estuarine Salt Marshes, Cape Estuarine Salt Marshes and Subtropical Estuarine Salt Marshes. Sarcocornia tegetaria is thus a typical coastal species, however, in Eastern Cape it occurs in tidal habitats along rivers such as the Bushmans, Kowie and Kariega rivers as deep inland sometimes as 15 km.

Conservation

Sarcocornia tegetaria is a widespread species so far recorded in almost all major estuaries of southern Africa. Some of these estuaries are under serious pressure by being exposed to siltation or barring the sea water from penetrating the estuary and hence drastically changing the hydrology of the tidal regime (see Turpie 2004; Turpie et al.2002). We suggest that at this stage the IUCN conservation status of S. tegetaria is of Least Concern (LC).

Note

Projections of the exostesta epidermal cells are an important diagnostic character in the genus Sarcocornia (Brenan 1988; Steffen et al.2007; Alonso & Crespo 2008). The southern African S. tegetaria differs from the Eurasian S. perennis mainly in seed morphology. The seeds of S. perennis are coated with irregular knobs (Davy et al.2006) whereas the seeds of S. tegetaria are covered with long hooked hairs at the edge and are ruminate in the centre. Due to morphological and ecological similarities plants now clearly identified as S. tegetaria have usually been misidentified as S. perennis in the past. The specific epithet has been chosen because of the mat-forming habit of this species. Our morphological studies revealed that many of the specimens which could be ascribed to Sarcocornia tegetaria possess sets of characters transitional between S. tegetaria and other species of the genus. We hypothesise that when occurring sympatrically, frequent hybridisation takes place between S. tegetaria and other species of the genus. The most common putative hybrids were observed between S. tegetaria and S. pillansii (Moss) A. J. Scott (e.g., Western Cape, Langebaan, West Coast National Park, Seeberg Bird Hide; Mucina 090306/04 MJG!, NBG!) and S. natalensis (Bunge ex Ung.-Sternb.) A. J. Scott (e.g., Ward 8896 PRE!; Eastern Cape, Kleinemonde E, Lynedoch R.). This is despite S. tegetaria and the latter two Sarcocornia species belonging to different clades as revealed by both nuclear and chloroplast markers (Steffen 2006). These taxa, however, often overlap with S. tegetaria in contact zones such as upper tidal zones. Less frequently putative hybrids were found between S. tegetaria and S. capensis (Eastern Cape, Port Elizabeth, Swartkops R. estuary; Archibald 4927 BOL!) and S. tegetaria and S. littorea (Moss) A. J. Scott (Western Cape, Stillbaai, mud flats near caravan camp; Bohnen 4162 PRE!, NBG!). A third species, Sarcocornia mossambicensis Brenan shows strong similarities to S. perennis and S. tegetaria in both morphology and ecology. Furthermore, it occurs in Mozambique where it often grows sympatrically with S. tegetaria (Brenan 1988). Sarcocornia mossambicensis can be distinguished from the latter only when it is flowering and fruiting. Its seeds are ornamented with minute papillae and the inflorescences are cylindrical (A. O. D. Mogg 29306 LISC!, type, A. O. D. Mogg 29305 LISC!, A. O. D. Mogg 28914 LISC!), while they are tapering in S. tegetaria.