Marasmodes oppositifolia, Magee & Koopman, 2017

Magee, A. R., Ebrahim, I., Koopman, R. & von Staden, L., 2017, Marasmodes (Asteraceae, Anthemideae), the most threatened plant genus of the Cape Floristic Region, South Africa: Conservation and taxonomy *, South African Journal of Botany 111, pp. 371-371 : 371-

7. Marasmodes oppositifolia

Magee & Koopman sp. nov. Type: South Africa. Western Cape, Worcester (3319): Romansrivier Nature Reserve (–AC), 9 Jul 2012, Magee & Koopman 499 (NBG, holo.!; BOL!, K!, PRE!, NBG!, S!, iso.).

Weak, single or few-stemmed, sparsely leafy shrublets, 0.2–0.4 m tall. Leaves opposite, restricted to upper branches or branch tips, caducous, suberect, linear, 9–20 × 1 mm, simple, mucronulate, secondary basal lobes absent; axillary fascicles absent. Capitula solitary, terminal or on axillary shoots 5–150 mm long. Involucre campanulate to broadly campanulate, 5–8 × 5–8 mm; bract margins and apices scarious, sessile glands at appendage base inconspicuous, stereome somewhat prominent; outer bracts broadly ovate, 1.5–2.0 mm long, margin and apex very narrowly scarious; middle bracts ovate, 3–4 mm long, margin and apex narrowly scarious; inner bracts oblong, 4.0– 5.5 mm long, margins narrowly scarious, apex with a prominent scarious appendage, yellowish brown. Florets ca. 20 to 30; limb deeply 5-lobed from below midpoint; lobes erect to recurved. Pappus with adaxially longer, adaxial scales to less than half corolla tube length.

Diagnostic characters

This is the only species with opposite primary leaves and with the floral limb deeply 5-lobed from below the midpoint ( Fig. 2N–P ).

Distribution and ecology

Marasmodes oppositifolia

Is known from a single 20 ha fragment of seasonally damp Breede Alluvium Fynbos between Worcester and Wolseley ( Fig. 6 ). Despite this site being well-collected and long known as a hotspot of threatened species (19 other threatened species occur there), M. oppositifolia was first discovered in 2010, through CREW's survey efforts. Further surveys of remaining fragments of Breede Alluvium Fynbos have failed to locate any other subpopulations. The site has been secured for conservation through a 15-year biodiversity agreement, whereby the landowners retain ownership of the land, but agree to manage the site for conservation. It is not certain that the contract will be renewed after it comes to an end. There are some alien invasive plants present at the site, which need to be cleared to prevent them from outcompeting native species. Recent road construction at the edge of the site may have altered water flow patterns in the wetland, which may impact this wetland-dependent species in future. The population is being monitored to determine the impact of these threats over time. There are currently only about 20 plants, and therefore the species is assessed as Critically Endangered according to criteria B1ab(iii,v) + 2ab(iii,v); C2a(i,ii); D.

Additional specimens examined

South Africa. WESTERN CAPE: 3319 (Worcester): Romansrivier Nature Reserve (– AC), 26 Apr 2013, Koopman 1180 ( NBG, BOL).

Figures

Fig. 2. General morphology of Marasmodes crewiana (A–C), M. defoliata (D & E), M. dummeri (F & G), M. fasciculata (H & I), M. macrocephala (J & K), M. oligocephala (L & M), and M.oppositifolia (O & P).

Fig. 6. The known geographical distribution of Marasmodes oppositifolia (star), M.trifida (circle) and M.undulata (triangle).