Triglochin compacta (Juncaginaceae)
Plants (10–)15–50 cm high, with fusiform bulbs; bulbs covered in dry, rather soft, brown fibres, these up to 5 cm long. Leaves few, formed after flowering, mostly reaching only half of the height of plants. Outer leaves strap-shaped, shorter and wider than inner leaves, up to 4 cm long, mucronate, inner leaves abruptly narrowing above the ligule, less than 0.5 mm wide, distinctly longer than outer leaves, leaves generally larger and more numerous after fruit maturity. Inflorescences dense, with (6–)10–50 flowers. Flowers 1 .5–3 mm long. Pedicels elongated at fruiting time, up to 2–7 mm long, mostly curved inwards towards the apex. Infructescences 5–20 cm long. Fruits narrowly ovoid, 6–10 mm long, 1–2 mm wide. Mericarps dorsally curved upwards, connate at the carpophore; tips curved outwards. Carpophore often with three basal membranous outgrowths.
Proposed IUCN conservation status. Data Deficient (DD). The low number of collections of this taxon could be a result of poor sampling (failure to distinguish this species in the field from the much more common Triglochin bulbosa subsp. bulbosa), habitat loss, natural rarity, or a combination of these factors. Some of the sandveld areas (system of lowland stabilised dune-fields) have been suffering from pressure of urban sprawl through both the spread of formal housing development and the explosive spread of informal settlements on the Cape Flats (now part of the Cape Town metropolis). The conservation status of this taxon can only be judged once an intensive search for extant localities has been conducted. We therefore suggest classifying Triglochin compacta as Data Deficient.
Endemic to South Africa: restricted mainly to the Western Cape Province where it occurs in the Cape Peninsula as far east as Goukamma on the Garden Route and in Seweweekspoort in Klein Swartberg Mountains, the Cederberg and in a handful of localities in the Northern Cape Province in the surroundings of Nieuwoudtville and near Kommagas (Namaqualand). The Kommagas collection is an unusual outlier and requires further attention. Unfortunately recent material from this locality was not available.
Triglochin compacta is invariably found on deep (mainly nutrient-poor) sands. When of marine origin, these sands form stabilised (and highly leached) inland sand dunes, always outside the current direct influence of the sea. In some places at higher altitudes these deep sandy sediments are derived in situ from arenites such as Table Mountain and Nardouw sandstones. The vegetation types characteristically supporting this taxon are Hangklip Sand Fynbos, Cape Flats Sand Fynbos, Albertinia Sand Fynbos, Knysna Sand Fynbos, Cederberg Sandstone Fynbos and Bokkveled Sandstone Fynbos (sensu Mucina & Rutherford, 2006).
Flowering mostly in autumn from (ii)iii–v; some fruiting material was collected in vi.
Apart from its initial description by Adamson (1943), this species has been incorrectly classified as being synonymous with Triglochin bulbosa. However, the two species can be easily distinguished by phenology as well as morphology (see Triglochin bulbosa for a comparison between these two sympatric species). The affinities of Triglochin compacta to T. milnei will be discussed under the latter species.