Macowania revoluta Oliv.

Clark, Vincent Ralph, Bentley, Joanne, Dold, Anthony P., Zikishe, Vathiswa & Barker, Nigel P., 2016, The rediscovery of the Great Winterberg endemic Lotononis harveyi B. - E. van Wyk after 147 years, and notes on the poorly known Amathole endemic Macowania revoluta Oliv. (southern Great Escarpment, South Africa), PhytoKeys 62, pp. 113-124 : 115-120

Macowania revoluta Oliv. Fig. 1 ; Plate 2

Remarks.

Macowania revoluta , the type species of Macowania , was first collected by Peter MacOwan in the eastern part of the Amatholes sometime prior to 1870 and described by Daniel Oliver in Icones Plantarum ( Hooker 1867-1871). This almost exclusively southern African genus was later revised by Smith (1927). Relatively few collections of Macowania revoluta exist (most specimens being repeat collections by a few historical collectors, see below). Raimondo (2008) indicates that this species had not been re-collected since before 1949, although herbarium investigations by JB indicate that there is one collection from 1976 (albeit with virtually no other data).

The first concrete records of this species’ continued existence was a collection in July 2010 by JB and Nicola Bergh (Compton Herbarium) in the vicinity of Keiskammahoek (Locality 1 - the closest record to the type locality), followed by a second specimen in October 2010 by APD near the Madonna & Child Waterfall in Hogsback (Locality 2). Following this, in December 2014, the species was found by VRC to be abundant in the central Amathole mountains along the Amatola Hiking Trail (Localities 3-5). In March 2015 another plant was recorded by VZ from Isidenge State Forest on the road to Evelyn Hut (one of the overnight huts on the Amatola Hiking Trail; Locality 6).

Key characters confirming rediscovery.

The plant is typically an erect, candelabra-like shrub 50 cm to three metres tall, but often lax and weedy when small. The leaves are distinctly linear, dark green, sticky glandular and sweetly aromatic with strongly revolute margins (hence its specific name) and a raised abaxial midrib. Both disc and ray florets are yellow, with the ray floret petals rounded upwards. The involucre is bell-shaped with distinctly long bracts; the margins are strikingly dark-brown.

Another species endemic to the GWA, Arrowsmithia styphelioides - earlier believed by Hilliard and Burtt (1985) to be closely affiliated to Macowania - has since been found by recent phylogenetic analysis to be nested within Macowania , as sister to Macowania revoluta ( Bentley et al. 2014; the taxonomic revision is currently in progress). Arrowsmithia styphelioides differs in its sharply acuminate, ovate leaves, absence of the raised abaxial midrib, as well as in several features of the reproductive organs. Otherwise, no other Macowania species are currently known from the GWA ( Clark et al. 2014), with the next closest known population of another species ( Macowania pulvinaris N.E.Br.) being on the Andriesberg, 115 km to the north.

Population assessment.

At Locality 1, Macowania revoluta was found to be locally abundant, with plants in excess of one meter in height and forming the dominant species. Only one plant was noted at Locality 2, growing on the edges of a derelict Pinus patula plantation and Acacia mearnsii De Wild. invasions. Locality 3 contained about 20 plants, 0.5-1 m tall, with two in flower and many others in seed. Locality 4 comprised a large colony (ca. 50 m × 100 m in extent) with Macowania revoluta (1-3 m tall) forming the dominant species; many were in flower. Locality 5 consisted of a dense but small colony (1-3 m tall) covering ca. 50 m × 10 m; also with many in flower. Only one plant was located at Locality 6, and was not in flower.

Habitat and ecology.

Based on the information on the type material, Clark et al. (2014) suggested that this species should be looked for along forest edge and in adjacent grassland. This was a good deduction, as the plants form dense colonies on wet scarp slopes, on cliff-tops, on the margins of indigenous forests, and on the edges of pine plantations and alien thickets. Macowania revoluta generally prefers wet areas, and can form the dominant component of mountain fynbos in suitable habitat, co-occurring with various Cyperaceae , Erica species, Pelargonium cordifolium (Cav.) Curtis, Psoralea glabra E.Mey., Pteridium aquilinum (L.) Kuhn subsp. aquilinum , Rubus rigidus and Widdringtonia nodiflora (L.) Powrie.

Conservation status and threats.

Macowania revoluta is currently listed as Data Deficient ( Raimondo 2008), but is obviously much more common than previously thought. Despite the species’ local abundance, its ruderal tendencies, and being somewhat tolerant of less dense alien vegetation, it is (mostly) known from one quarter degree grid on a small mountain range that is under severe pressure from woody alien invasive species (notably Acacia dealbata Link, Acacia mearnsii , Acacia melanoxylon R.Br. and Pinus patula ). Furthermore, the potential impacts of climate change on this (and other local montane endemics) is currently unknown. Also, it’s response to fire (and autecology in general) is unknown and requires investigation. Accordingly we recommend the status ‘Rare’.

Recommended areas for further exploration.

Macowania revoluta potentially occurs anywhere along the wet southern scarp of the Amathole Mountains, between Katberg Pass and Stutterheim. So far it has not been recorded on the adjacent Great Winterberg.

Historical collections and localities

(a selection of these is mapped in Figure 1 ). South Africa, Eastern Cape Province, 3227CA & 3227CD, Amathole Mountains (King Williams Town): rocky summit of Pirie Mountain, Buffelsrivier, Kaffraria (label detail differs among the duplicates). October 1887 (this date on the GRA specimen is a bit of an enigma, as it post-dates the species description). Macowan P 2013 (BOL, E, GH, GRA, K, NYBG, P, PRE; type specimens).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): summit of Pirie mountains, Kaffraria. 1200 m (4000'), October 1884. Leighton (J?) 225 (GRA, NBG, PRE).

- Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): summit of Mount Pirie. May 1887. Tyson W 2935 (PRE).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): Perie (=Pirie), Kaffraria. August 1892. Sim TR s.n. (BOL).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): Pirie. 1200 m (4000'), September 1892. Sim TR 3283 (NU).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): Summit of Perie (=Pirie). 900 m (3000'), November 1893. Flanagan HG 2144 (GRA, BOL).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): Summit of Perie (=Pirie) mountains. 11th September 1901. Galpin EE 5930 (PRE).

-Eastern Cape Province, 3226DB, Amathole Mountains (Victoria East): Hogsback, common in scrub. January 1920. Rattray G 304 (GRA).

-Eastern Cape Province, 3227CA, Amathole Mountains (Keiskammahoek): Wolf River Plateau, forest margins in scrub. 29th October 1921. Stayner FJ 28 (GRA, PRE).

-Eastern Cape Province, 3226DB, Amathole Mountains (Cathcart): Hogsback. September 1925. Pole Evans IB 1748 (PRE).

-Eastern Cape Province, 3226DB, Amathole Mountains (Stockenstrom): hillside above forest at Hogsback. 28th October 1946. Esterhuyse E 13,249 (BOL).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): Wolf Ridge, Hogsback. 1200 m (4000'), 10th September 1947. Story R 3119 (GRA, PRE).

-Eastern Cape Province, 3227CA, Amathole Mountains (Keiskammahoek): Wolf River Forest. 18th September 1947. Dyer RA 104 (GRA).

-Eastern Cape Province, 3227CA, Amathole Mountains (Keiskammahoek): Gwili-Gwili Mountain, old military road to Evelyn Valley. 25th April 1949. Story R 3797 (PRE).

-Eastern Cape Province, 3227CA, Amathole Mountains (Keiskammahoek): No details. 1976. Gibbs Russell s.n. (NU).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): summit of Mount Pirie. No date. Macowan P 9053 (PRE).

-Eastern Cape Province, 3226BC, Katberg (Fort Beaufort): no details. No date. Macowan P s.n. (PRE).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): Pirie. November, no year. Sim TR 1029 (PRE).

-Eastern Cape Province, 3227CA, Amathole Mountains (King Williams Town): Pirie. No date. Sim TR 3130 (NU).

Recent collections and localities.

South Africa, Eastern Cape Province, 3227CA, Amathole Mountains (Stutterheim): between isiDengi Forest Station and Evelyn Valley Forestry Station. 32°43'32"S, 27°14'30"E, 1208 m, 27th July 2010. Bentley J 1 & 5 (NBG) (= Locality 1).

-Eastern Cape Province, 3226DB, Amathole Mountains (Cathcart): above Madonna & Child Waterfall, Hogsback, 32°36'27"S, 26°57'47"E, 1106 m, 7th October 2010. Dold T 15,010 (GRA) (= Locality 2).

- Eastern Cape Province, 3227CA, Amathole Mountains (Stutterheim): about one kilometre from Dontsa Hut on the Amatola Hiking Trail (Day 2 from Maden Dam side): in an earth road drain on the edge of a pine plantation next to a forestry road. 32°35'46"S, 27°13'29"E, 948 m, 3rd December 2014. Clark VR 450 (GRA) (= Locality 3).

-Eastern Cape Province, 3227CA, Amathole Mountains (Stutterheim): about five kilometres from Dontsa Hut towards Cata Hut on the Amatola Hiking Trail (Day 3 from Maden Dam side): montane fynbos and streams banks. 32°34'40"S, 27°10'31"E, 1371 m, 4th December 2014. Clark VR 451 (GRA) (= Locality 4).

-Eastern Cape Province, 3227CA, Amathole Mountains (Stutterheim): along the Amatola Hiking Trail towards Zingcuka Hut (Day 5 from Maden Dam side): along a cliff top above Wolf River Main Forest. 32°34'03"S, 27°05'04"E, 1259 m, 6th December 2014 (= Locality 5; only photographs were taken, by VRC).

-Eastern Cape Province, 3227CA, Amathole Mountains (Stutterheim): from Isidenge State Forest on the road to Evelyn Hut. 32°43'29"S, 27°14'37"E, 1198 m, 15th April 2015. (= Locality 6; only photographs were taken, by VZ).

Figures

Figure 1. Localities of Lotononis harveyi B. - E. van Wyk and Macowania revoluta Oliv. in the Great Winterberg-Amatholes, Eastern Cape, South Africa. Cartography by J. Bentley.

Plate 2. The poorly known Great Winterberg-Amatholes endemic Macowania revoluta Oliv. A a capitulum showing the distinctive dark involucral bract margins (Bentley J 1) B shrubby, candelabra growth-habit (above Wolf River Main Forest along the Amathole Hiking Trail, specimen not collected) C detail of flowering stem (Bentley J 1) D young plant showing ruderal tendencies (Clark VR 451). Photographs by C. McKune (A), V. R. Clark (B, D) and N. Bergh (C).