The vegetation ecology of the Witteberg and Dwyka Groups south of Worcester, Western Cape Province, South Africa

The vegetation supported by the Witteberg and Dwyka Groups south of Worcester is a diverse mosaic of fynbos-, renosterveld- and succulent karoo vegetation units sustained by a winter-rainfall pattern. Elytropappus rhinocerotis (renosterbos) dominated plant communities are found on finer grained soils derived from the various mudrock-dominated formations of the Witteberg Group, a Passerina truncata (gonnabos) dominated shrubland with large Protea shrubs and / or small Protea trees where the substrate is largely influenced by the sandstone-dominated formations of the Witteberg Group, a grass dominated Capeochloa arundinacea (Olifantgras) shrubland where both mudrock-dominated and sandstone-dominated formations influence the substrate as a result of folding, a karoo Hirpicium integrifolium (Haarbossie) dominated shrubland where succulents are in abundance on the Dwyka tillite, and a distinct Thamnochortus bachmannii restio-dominated sandveld in areas where deep aeolian sand had accumulated. The differences in vegetation communities are mainly based on geology with consequent soil characters and degree of rockiness, as well as topography, moisture availability and the water holding capacity of the soil. Although slope, aspect and elevation can sometimes be associated with specific plant communities, geology, soil pH and rock cover are the principal elements responsible for shaping the vegetation mosaic. Rather than a broad ecotone, the vegetation of the study area is understood as a complex mosaic mountain vegetation entity.Environmental SciencesPh. D. (Environmental Sciences

An ecological assessment of the Holsloot River, Western Cape, South Africa

Human related activities have influenced the rivers of the southern Western Cape since as early as the 1700’s. As there is no detailed information available on ecological status of the Holsloot River, a tributary of the Breede River, this study aimed to gain insight into the effect of impacts associated with human activities on the habitat integrity of this river. The study intended to understand how seasonal changes, catchment characteristics and events are reflected in the ecological status of habitats along the river by applying bio-monitoring and river health measurements at selected sites in the upper, middle and lower reaches of the Holsloot River and compare the results to that of an undisturbed reference site. Results obtained in this study are compared with data gathered in 2008/2009 to determine if the ecological status of the river had changed in the period between the two sampling times. The study included assessment of the ecological status of the river based on standard bio-monitoring protocol (SASS5, IHI, IHAS and VEGRAI) as well as in situ water quality analysis (pH, dissolved oxygen, electrical conductivity and total dissolved solids). The construction of the instream Stettynskloof Dam changed the configuration of the riparian zone and river channel in the upper catchment area. Agricultural- and other human related activities, with consequent water abstraction, non-point-source pollution, loss of riparian vegetation, as well as dense stands of alien invader plants influence flow patterns and affects river ecology, especially in the dry summer months. Providing sufficient stream flow and adequate water levels, human related activities can create a larger variety of habitat types available that can support larger biodiversity and higher productivity. The level of inundation and stream flow, influenced by water abstraction as well as irrigation return-flow from extensive drainage systems especially in the dry months, contribute to the loss of biodiversity in the middle and lower reaches of the river. Where the upper reaches of the river are largely natural with few modifications, the habitat integrity deteriorates in the middle reaches so much so that ecosystem functioning are collectively impaired in lower reaches due to human related impacts. Sensitive macro-invertebrates found at lower seriously impacted parts of the river however, were in all probability washed down from lower impacted upstream habitats and may expectedly be able to again occupy habitats downstream if water quality and habitat availability improves.Environmental SciencesM. Sc. (Environmental Science

Pelargonium hammansbergense E. M. Marais & A. le Roux 2021, sp. nov.

Pelargonium hammansbergense E.M.Marais & A.le Roux, sp. nov. (Fig. 2). Diagnosis: ─The yellow flowers with prominent dark red blotches on the posterior petals are similar to those of P. moniliforme Harvey (1860: 264) and P. vinaceum E.M. Marais (2000: 190), but P. hammansbergense differs in that the erect to patent leaves are simple to pinnately divided, the scape branched, and the anterior stamens more or less the same length as the sepals. Both P. moniliforme and P. vinaceum have simple to ternate, prostrate leaves, unbranched scapes and the anterior stamens always longer than the sepals. Type: ─ SOUTH AFRICA. Western Cape: Hammansberg, on farm Lemoenpoort, south of Worcester (3319 CD), 14 October 2014, Le Roux & De Wet 1305 (holotype NBG!; isotypes K!, PRE!). A deciduous geophyte 90–110 mm tall when in flower. Tuber: turnip-shaped, moniliform root covered with flaking dark brown periderms, 12–15 mm long and 10–15 mm diam. Leaves: radical, prostrate to erecto-patent, vary from simple to trifoliolate to finely pinnately divided, petiolate; lamina or main pinna of simple or trifoliolate leaves elliptic to ovate, 25–30 x 16–18 mm, bases cuneate, apices obtuse, margins entire to irregularly crenate, minor pinnae ovate, 15–16 x 8–9 mm, bases cuneate, apices obtuse, segments of finely divided laminae 2 mm wide, adaxially covered with short erect stiff hairs, abaxially glabrous, margins sparsely ciliate with soft hairs; petiole patent-erect, pale green, 20–90 mm long, covered with appressed curly hairs and short glandular hairs, sparsely interspersed with appressed stiff hairs; stipules subulate, ciliate, 7–10 mm long, adnate to petiole, apices free. Inflorescence: scape 15–30 mm long, covered with distally appressed curly hairs interspersed with long glandular hairs; branched, bearing 2–3 pseudo-umbellets with 5–10 flowers each; peduncles 25–60 mm long, 1–2 mm diam., pale green, covered with distally appressed curly hairs interspersed with long glandular hairs; bracts lanceolate, 2–3 mm long, abaxially densely hirsute with appressed stiff hairs interspersed with glandular hairs; flower buds, flowers and fruits erect. Pedicel ± 0.5 mm long. Hypanthium 20–29 mm long, 3.0–4.8 times the length of the sepals, pale reddish green, densely covered with appressed curly hairs, interspersed with long glandular hairs. Sepals 5, posterior one erect, others reflexed, 6.0–7.5 x 1.5–3.0 mm, lanceolate, reddish green with membranous margins, abaxially covered with glandular hairs, sparsely interspersed with appressed curly hairs. Petals 5, cream-coloured to pale yellow or yellow, spathulate, patent during anthesis; posterior two with prominent wine-red blotches in the centre and claws with or without wine-red feather-like markings, 15.0–17 x 5.0–6.0 mm, length/width ratio 2.8–3.3, apices rounded to shallowly emarginate, bases narrowly cuneate; anterior three 10–13 x 3–5 mm, apices rounded, seldom shallowly emarginated, bases attenuate. Stamens 10, basally connate, staminal column 1.0– 1.5 mm long, smooth, white; perfect stamens 5, posterior filament 3 mm long, lateral two filaments 4.5–5.0 mm long, anterior two filaments 7.0– 7.5 mm long, more or less the same length as the sepals, protrude from the flower, anthers dark red, 1.5–2.0 mm long, pollen orange. Gynoecium: ovary 3.0– 3.5 mm long; style 1.0– 2.5 mm long, pink; stigma with 5 recurved branches, 1.5–1.8 mm long, adaxially dark red. Fruit: a 5-parted schizocarp, bases of mericarps 4 mm long, with glandular hairs, tails 22–24 mm long Chromosome number: unknown. Flowering period: ─Early spring, during October. Habitat: ─ It grows on loam slopes in full sun in a Euryops rehmannii Compton (1931: 321) ─ Elytropappus rhinocerotis Lessing (1832: 344) plant community which forms part of the Elytropappus rhinocerotis (Renosterbos) shrubland component of the Winter-rainfall Mountain Mosaic Veld south of Worcester (Le Roux 2018). The plants occur on the south-eastern slope of Hammansberg (425–430 meters above sea level) where the vegetation is supported by acidic (pH 4.3) rocky loam soil with a considerable percentage of clay (Le Roux 2018), derived from glacial tillite of the Dwyka Group (Karoo Supergroup) (Gresse 1997, Gresse & Theron 1992). Annual rainfall (mainly in the winter months) at the site rarely exceeds 220 mm. Distribution: ─An endemic of the Breede River Valley in the Western Cape, known from Hammansberg on the farm Lemoenpoort and a nearby farm Moddergat south of Worcester (Fig. 1). Diagnostic characters: ─The spathulate yellow petals and the anterior stamens more or less the same length as the sepals are similar to those of P. aridicola, P. hirtipetalum and P. tripalmatum. Pelargonium hammansbergense is characterized by the prominent dark blotches on the posterior petals and the prostrate to patent-erect simple to pinnately divided leaves. Pelargonium aridicola, P. hirtipetalum and P. tripalmatum have dark red feather-like markings on the posterior petals. Pelargonium hirtipetalum is known for the soft hairs covering the petals, P. aridicola for the fine pinnately divided leaves and P. tripalmatum for its tripalmate compound leaves. Conservation status: ─Although P. hammansbergense occurs in a small area south of Worcester, it grows in mountainous areas currently not applied for agricultural activities. Etymology:− The specific epithet refers to the locality of the type specimen. Notes: ─Although the yellow flowers with the prominent dark red blotches on the posterior petals and the protruding stamens of P. hammansbergense resemble those of P. moniliforme and P. vinaceum, the simple to pinnately divided leaves, branched scape and the anterior stamens more or less the same length as the sepals, the first mentioned fit in best with the morphology of the P. aridicola group. Both P. moniliforme and P. vinaceum have unbranched scapes, a characteristic not common in P. section Hoarea and the anterior stamens are always longer than the sepals and protrude from the flower. Additional specimens examined: ─ SOUTH AFRICA, Western Cape: Hammansberg, on farm Lemoenpoort, south of Worcester (3319 CD), 9 September 2015, E. M . Marais 473 (STEU!); farm Moddergat (3319 CD), 13 October 1979, G. J . Rossouw 446(A & B) (NBG!).Published as part of Marais, Elizabeth M. & Roux, Anso Le, 2021, Two new species of Pelargonium (Geraniaceae) from the Western and Northern Cape Provinces (South Africa) and their position within P. section Hoarea, pp. 92-100 in Phytotaxa 516 (1) on pages 94-96, DOI: 10.11646/phytotaxa.516.1.7, http://zenodo.org/record/531660

Pelargonium roseopetalum E. M. Marais 2021, sp. nov.

Pelargonium roseopetalum E.M.Marais, sp. nov. (Fig. 3) Diagnosis: ─The reflexed posterior petals and protruding stamens are similar to those of P. reflexipetalum but P. roseopetalum differs in the pale pink to almost white flowers and prostrate simple to ternate leaves. P. reflexipetalum has bright pink flowers and prostrate to erect pinnatisect to bipinnatisect leaves. Type: ─ SOUTH AFRICA. Northern Cape: Oorlogskloof Nature Reserve (3119 AC), 12 October 2006, E. M . Marais 456 (holotype NBG!; isotypes K!, PRE!). A deciduous geophyte 80–150 mm tall when in flower. Tuber: turnip-shaped, elongated, sometimes moniliform root, covered with flaking dark brown periderms, 10–35 mm long and 5–10 mm in diam. Leaves radical, rosulate, simple, seldom ternate, petiolate; lamina or main pinna ovate to cordate, 10–37 x 6–30 mm, bases usually cuneate, apices obtuse, margins entire to irregularly crenate, adaxially and abaxially sparsely covered with long and short soft hairs interspersed with long and short glandular hairs; petiole prostrate, 15–80 mm long and 1.0– 1.5 mm in diam., densely covered with long glandular hairs; stipules subulate, ciliate, ± 10 mm long, adnate to petioles with apices free. Inflorescence: scape 40–60 mm long, reddish green, densely covered with distally appressed curly hairs interspersed with long glandular hairs, branched, bearing 2–4 pseudo-umbellets with 3–4 flowers each; peduncles 75–90 mm long, pale reddish green, densely covered with distally appressed curly hairs interspersed with long glandular hairs; bracts subulate, 2.0–2.5 x 1.0 mm, abaxially densely hirsute; flower buds, flowers, and fruits erect. Pedicel ± 0.5 mm long. Hypanthium 9–13 mm long, 2.0–2.5 times the length of the sepals, pale green, densely covered with distally appressed curly hairs interspersed with long glandular hairs. Sepals 5, reflexed during anthesis, lanceolate, apices acute, 5 x 1.5–2.0 mm, bases red, apices green, margins white, abaxially densely covered with distally appressed curly hairs interspersed with long glandular hairs. Petals 5, pale pink to almost white; posterior two usually without any markings, sometimes with dark red streaks, narrowly spathulate, 11.5–12.0 x 1.5–1.7 mm, length/width ratio 6.8–8.0, claws 9 x 1.5–2.0 mm, apices truncate or emarginate, reflexed during anthesis; anterior three with dark pink V-shaped markings, spathulate, 9.0–9.5 x 1.5–2.0 mm, bases attenuate, apices rounded, patent during anthesis. Stamens: 10, basally connate, staminal column 1.5 mm long, smooth, white; perfect stamens 5, posterior filament 4 mm long, lateral two filaments 4.5 mm long, anterior two filaments 5 mm long, more or less as long as the sepals, protruding from the flower, apices of free filaments red; staminodes 2.5–3.0 mm long; anthers wine red, 1.2–1.5 mm long, pollen orange. Gynoecium: ovary 2.0– 2.5 mm long; style 0.5 mm long, wine-red; stigma branches recurved, 0.5 mm long, wine-red. Fruit: not seen, Chromosome number: unknown. Flowering period: ─November. Habitat: ─Growing in fynbos on soil derived from sandstone in a predominantly winter-rainfall area with an average precipitation of 300–400 mm per annum. Rain falls mainly between March and October, with an extreme variation in the duration and abundance of the rain (Snijman & Perry 1987). Distribution: ─An endemic of the Oorlogskloof Nature Reserve near Nieuwoudtville in the Northern Cape Province (Fig. 1). Diagnostic character: ─The reflexed posterior petals and protruding stamens are similar to those of P.reflexipetalum and P. tripalmatum. All three species have spathulate or narrowly spathulate posterior petals with reflexed apices and in all of them the anterior stamens are the same length or slightly longer than the sepals and protrude from the flower. The three species differ, however, in that P. tripalmatum has yellow flowers and large tripalmate leaves (Marais 1996), P. reflexipetalum has bright pink flowers and small pinnatisect leaves (Marais 1997a) and P. roseopetalum has pale pink to almost white flowers and prostrate, simple to ternate leaves. Conservation status: ─Occurring in the conserve area of the Oorlogskloof Nature Reserve. Etymology: ─The specific epithet describes the pale pink flowers.Published as part of Marais, Elizabeth M. & Roux, Anso Le, 2021, Two new species of Pelargonium (Geraniaceae) from the Western and Northern Cape Provinces (South Africa) and their position within P. section Hoarea, pp. 92-100 in Phytotaxa 516 (1) on pages 96-97, DOI: 10.11646/phytotaxa.516.1.7, http://zenodo.org/record/531660