Acanthopsis hoffmannseggiana (Nees) C.B. Clarke (1901: 35)

Steyn, Hester M. & Van Wyk, Abraham E., 2015, Taxonomic notes on the Acanthopsis disperma-hoffmannseggiana complex (Acanthaceae, tribe Acantheae), with an interim key to members of the genus, Phytotaxa 219 (1), pp. 1-26 : 16-21

5. Acanthopsis hoffmannseggiana (Nees) C.B. Clarke (1901: 35) ; Meyer (1961: 22); Balkwill (2012: 257) ( Figs. 1 , 3E , 8 )

Type: —[ SOUTH AFRICA. Northern Cape:] Cape of Good Hope [Without precise locality], Hoffmannsegg s.n. (lectotype B-W11728-010 scan! designated here; iso-lectotype GZU000251757 , fragment scan!) .

Acanthodium hoffmannseggianum Nees in Candolle (1847: 277).

Annual to short-lived perennial acaulescent herbs or subshrubs 100–150(–200) mm tall with reduced branching in perennials (internodes <5 mm long). Leaves tufted, oblanceolate, lanceolate to strap-shaped, (30–)50–90(–150) × 10–20(–25) mm; margin flat to undulate, irregularly dentate to coarsely dentate spinose; spines fine to strong, 2–4(–7) mm long; with strigose to spreading short hairs, usually interspersed with stalked glandular hairs; often with scattered longer hairs on main vein; base attenuate; petiole (1–)3–8(–12) mm long. Inflorescences (1–)3–5(–8) per plant; 25– 65(–85) mm long, (12–)15–18(–20) mm in diameter. Bracts hemispherical to fan-shaped, 18–23 mm long, base 6–8 mm long, middle and upper bracts ending in 5 primary spines; central primary spine always compound (with 2 or 3 pairs of marginal secondary spines), lateral primary spines with 2 basal and 3(–5) marginal secondary spines; primary spines usually recurved and secondary spines spreading in fruit; bract base hirsute to pubescent with deflexed to spreading short hairs interspersed with stalked glandular hairs and some scattered long, silky hairs; ring of long, silky hairs adaxially at base of spines; spines usually with long, viscid glandular hairs, 0.2–0.3(–0.4) mm long (see notes), often velvety due to additional short, white silky hairs (Western Cape), or villose due to additional long, white silky hairs (central Northern Cape, South Africa). Bracteoles lanceolate 6–9 mm long, silky hairy, often with glandular hairs at tip. Calyx with dorsal sepal ovate to obovate, cuspidate, 11–14(–15) mm long, silky hairy especially adaxially, often with glandular hairs abaxially, 7–9-veined from base; ventral sepal ovate, 9–11 mm long, silky hairy, often with glandular hairs abaxially; lateral sepals 9 mm long, densely silky hairy. Flowers with variable colours, white with purple veins, blue-purple with white throat, or yellowish; corolla (23–)25–30 × 9–12(–13) mm, tube 9–12 mm long; pubescent, often with some glandular hairs; central lobe longer than wide or equal, constricted at base, truncate to emarginate. Stamens with purple-black to brown anthers, 2 mm long; filaments 4–5 mm long, glandular, hairy towards base. Style with patch of glandular hairs at base. Capsules ovate in face view, flattened, glabrous, shiny, 6–7 × 2–3 mm, 2-seeded. Seeds 4 × 3 mm, covered with long white hygroscopic hairs.

Eponymy: —The specific epithet commemorates the German botanist Johann Centurius von Hoffmannsegg [1766–1849] from whom Willdenow had received the type specimen.

Distribution, ecology and phenology: — Acanthopsis hoffmannseggiana is restricted to southeast Namibia and adjacent central South Africa (Northern Cape) with a disjunct outlier presence further south in the Western Cape) ( Fig. 1 ). This range falls within the Nama-Karoo Biome ( Rutherford & Westfall 1994, Low & Rebelo 1996, Mucina & Rutherford 2006) where it receives predominantly late summer and autumn rains with an average of 100–300 mm per year. It prefers sandy plains, stony hillsides and ridges and is usually associated with weathered quartzite and granite, but also occurs on mudstone (in Prince Albert area) and limestone (Asbestos Mountains), usually at elevations between 650 and 1000 m. The Afrikaans vernacular names klappers and jakobregop was recorded by Theron 821 and Wasserfall 1092 respectively. Shearing 58 noted that the thorns are very poisonous, and Wasserfall 1092 that the leaves are eaten by stock. Flowering time: mainly March–October, perennial form from Pofadder area flowers between August and March.

Notes: —Ever since the establishment of Acanthodium hoffmannseggiana there has been confusion between the use of the names Acanthodium hoffmannseggiana and Acanthodium carduifolium . Nees in Candolle (1847) listed Acanthus carduifolius “(herb. Willdenow 11728)” (the specimen here selected as lectotype) in the protologue. On the type specimen (B-W11728-010) there are annotations alluding to both names: Ac [anthus] carduifolius (Schlechtendal’s handwriting and probably why Nees mentioned this name), Acanthopsis carduifolia (L.) Schinz (Schinz’s handwriting) and Acanthodium hoffmannseggianum (Nees’ handwriting). Nees in Candolle (1847) also noted that Thunberg confused Acanthodium hoffmannseggiana with Acanthus carduifolia Linneaus (1782: 294) . On both fragments in GZU, both names are in Nees’ handwriting. However, Nees in Candolle (1847) stated that these two species certainly differ from each other and kept them separate as distinct species. In 1864 Anderson listed Acanthodium hoffmannseggianum as a synonym of Blepharis carduifolia Anderson (1864: 35) , probably as a result of the confusing annotations on the specimens. This was upheld by Schinz (1890) who listed both names as synonyms of Acanthopsis carduifolia (L.f.) Schinz (1890: 200). Clarke (1901) resurrected A. hoffmannseggiana as a valid name and it has been acknowledged as a separate species since.

Acanthopsis hoffmannseggiana has the widest distribution of all Acanthopsis species and contains a number of different forms. The biggest variation occurs in the leaf and bract indumentum, flower colour, life cycle and distribution range. A villose bract form occurs mainly in the Kenhardt-Pofadder area, these plants are annuals (terophytes) usually with strap-shaped leaves (strigose indumentum), white, silky villose bracts (glandular hairs are often difficult to see) and white flowers with purple veins or lilac flowers with darker purple veins. A form with yellowish flowers occurs around Prieska and the Asbestos Mountains and a perennial herb/subshrub form with blue-purple flowers (white throat) occurs in the Prince Albert area in the Great Karoo and the Pofadder area in Bushmanland. The following specimens from the Pofadder area are included in A. hoffmannseggiana due to the leaf indumentum of spreading glandular hairs, life cycle (perennials), general appearance and distribution. These specimens, however, lack long, viscid glandular hairs on the bracts that characterise A. hoffmannseggiana , (Barker 8349, Sachse 893, Steyn 1908, Van Jaarsveld & Kritzinger 8070). In the southern Great Karoo (just north of the Swartberg Mountains), specimens to the west of this outlier distribution range are somewhat intermediate between A. hoffmannseggiana and A. dispermoides (found to the south of the Swartberg Mountains) with the bract indumentum consisting of short glandular hairs (<0.2 mm long), with longer silky hairs on the margins (shorter and less dense than A. dispermoides ), but the spreading, glandular leaf indumentum of A. hoffmannseggiana (Prince Albert form) (Acocks 17139, Bond, 841, Cattell & Cattell 215, Snijman 2334, Steyn 1900, Thode STEU2700, Venter 1434). The taxonomic significance of these variation patterns is not clear at the moment.

As all the various forms seem to grade into each other, they are here all included in a rather broad concept of A. hoffmannseggiana . However, further fieldwork and taxonomic evidence (notably comparative studies on trichomes and pollen) might well result in the recognition of infraspecific taxa in future.

Conservation status: — Acanthopsis hoffmanseggiana as currently circumscribed is a widespread and very variable species and is classified as Least Concern ( IUCN 2001) (L. von Staden, pers. comm. 2015).

Additional specimens examined: — NAMIBIA . Karas: Klein Karas, (2718 CA), October 1913, Dinter 3218 ( PRE!, SAM!) ; Farm Fortuin , (2719 CD), 22 February 1997, Ströhbach, Kubirske & Sheuyange 3010 ( WIND!) ; Warmbad Dist.; 20 mi. on Goodhouse rd. , hillside, (2818 CB), 24 July 1937, Galpin 14206 ( PRE!) ; Goodhouse Poort, (2818 CD), 22 June 1989, Van Wyk 8593 ( NMB!, PRE!, PRU!) ; Farm Lugeck: WAR 114. Im Rivierbett [In riverbed], (2818 DB), 22 May 1972, Giess & Müller 12117 ( M!, PRE!, WIND!) ; Keetmanshoop Dist.; 30 mi. from Ariamsvlei on road to Ham River Station, (2819 AB), 16 May 1955, De Winter 3558 ( M!, NBG!, PRE!, WIND!) ; Tussen Ariamsvlei en Karasburg , (2819 AB), 14 August 1961, Schweickerdt 2588 ( PRU!) ; Warmbad: sandige Flächen und schwarze Hügel westlich Ariamsvley , (2819 BA), 14 December 1957, Merxmüller & Giess 746 ( M!) ; Graswater: WAR 150. Granit-Quarzit Geröllfläche [Granite quartzite scree plain], (2819 CB), 17 May 1963, Giess, Volk & Bleissner 7044 ( WIND!). SOUTH AFRICA. Northern Cape: Pofadder , 20 km S of Onseepkans, (2819 CD), 16 July 1988, Dean 558 ( J!) ; Gordonia District. Augrabies Waterfall National Park. New part of park, close to picnic spot ( Af en Toe ), 699 m, (2819 DB), 22 August 2005, Steyn 758 ( PRE!) ; Kenhardt Div .; 14.2 mi. W of Bladgrond on Pofadder road, 3000 ft, (2819 DC), 22 February 1954, Comins 656 ( PRE!) ; Kenhardt District ; on tarred road between N14 and Onseepkans ., 866 m, (2819 DC), 5 August 2013, Steyn 1910 ( PRE!) ; Pofadder Dist ; 25 mi. van Pofadder op pad na Kakamas , (2819 DC), 17 July 1961, Van der Schijff & Schweickerdt 5716 ( PRE!) ; Kenhardt District . On the road to Nous ; 2–3 km N of N 14, 920 m, (2819 DD), 7April 2000, Balkwill, McDade & Lundberg 11797 ( J!) ; Riemvasmaak , 2800 ft, (2820 AD), 23 April 1988, Matthews 126 ( PRU!) ; 80 km vanaf Ariamsvlei op pad na Upington, (2820 BC), 26 June 1981, Van Wyk 4478 ( PRE!, PRU!) ; Great Bushmanland; Kalahari ; betw. Kakamas & Bladgrond, (2820 C), October 1938, Esterhuysen 1264 ( BOL!, PRE!) ; Gordonia District. Augrabies Waterfall National Park . New part of park, 1 km from one-way split in road in westerly direction (on tourist route), 656 m, (2820 CA), 23 August 2005, Steyn 784 ( PRE!) ; Augrabies Falls National Park . Near Ararat, (2820 CB), 25 June 2011, Du Plessis 130 ( PRE!) ; Kakamas District: Halfway between Augrabies and Marchand , ± 3–5 km West of Kakamas. 28°42.38’S 20°29.27’E, (2820 CB), 22 June 1999, Meyer 2113 ( PRE!) ; Kenhardt District ; 116 km E of Pofadder , 715 m, (2820 CD), 5 August 2013, Steyn 1909 ( PRE!) ; Keimoes ; nr. Keimoes , (2820 DB), 26 June 1950, Theron 821 ( PRE!) ; Kenhardt Div .; Kakamas Veld Reserve , 2100 ft, (2820 DC), 10 May 1952, Acocks 16357 ( PRE!) ; Kenhardt Div .; Kakamas , (2820 DC), no date, Fuller 5 ( PRE!) ; Kakamas Dist.; 5 mi. buite Kakamas op pad na Pofadder , (2820 DC), 17 July 1961, Van der Schijff & Schweickerdt 5694 ( PRE!, PRU!) ; Kenhardt Div .; Kakamas ; Letterkop Bot. Res. ‘ Harde & Sagte’ kamp, (2820 DC), 12 July 1946, Wasserfall 1092 ( PRE!) ; Upington , (2821 AC), 27 April 1961, Mostert 1308 ( PRE!) ; Upington Div., (2821 AC), 8 August 1961, Mostert 1424 ( NMB!, PRE!) ; Upington Div.; karakoelplaas, (2821 AC), 10 June 1965, Mostert 1633 ( PRE!) ; Kenhardt District. Dirt road from Upington to Groblershoop via Kleinbegin , 910 m, (2821 CB), 2 April 2010, Steyn 1747 ( PRE!) ; Hay Division: Rudesheim , (2822 DD), June 1920, Louw KMG 1 ( KMG!) ; Namaqualand District: Aggeneys: Black Mountain Area , 960 m, (2918 BA), 1 February 2000, Netnou 56 ( PRE!) ; Namaqualand District: Aggeneys: Black Mountain Area , (2918 BA), 2 February 2000, Nkoana 654 ( PRE!) ; Ridge E of Goodhouse turn-off en-route to Klein Pella , 786 m, (2918 BA), 23 August 2009, Steyn 1693 ( PRE!) ; Aggeneys District . Ghaamsberg. Plateau on rim of crater NW side ± 400 m NE of towers, 1120 m, (2918 BB), 31 March 1999, Anderson & Van Heerden 882 ( KMG!) ; Bushmanland ; Aggenys Mountain ; west of Pofadder, Soutkloof area WSW of Aggenys Farm, (2918 BB), 24 August 1977, Oliver, Tölken & Venter 51 ( PRE!) ; Namaqualand District, Klein Pella , 6.5 km NW of Klein Pella on 4×4 route, (2918 BB), 5 July 2013, Steyn 1905 ( PRE!) ; Namaqualand District, Klein Pella , along entrance road at foot of koppie, 654 m, (2918 BB), 5 July 2013, Steyn 1907 ( PRE!) ; District Namaqualand, Gamsberg. Top of Gamsberg , on south-eastern part of mountain plateau, 1145 m, (2918 BD), 13 October 2010, Sachse 925 ( PRE!) ; Namaqualand District: 32 km E of Aggeneys on road to Pofadder , 900 m, (2919 AA), 2 February 2000, Nkoana 676 ( PRE!) ; Pofadder, Eytees-Boomrivier, T’Goob-se-Berg , 880 m, (2919 AA), 9 June 2005, Nkoane 286 ( PRE!) ; Pofadder . Pellaberg East, (2919 AA), 1 May 1988, Van Jaarsveld & Leitch 9747 ( NBG!) ; Pofadder, Boomrivier Farm , (2919 AB), 10 June 2005, Nkoane 244 ( PRE!) ; Kenhardt District. Pofadder ; 10 km E of Pofadder , (2919 AB), 7 August 2011, Steyn, H.M. 1844 ( PRE!) ; Pofadder, 25 km east. Along tar road, (2919 BA), 4 May 1988, Dean 487 ( J!) ; Kenhardt District. SE of Pofadder. On road between Nuwedam and Banksvlei , 979 m, (2919 BB), 21 August 2005, Steyn 750 ( PRE!) ; Kenhardt District. SE of Pofadder. Between Nuwedam and Banksvlei , 993 m, (2919 BD), 21 August 2005, Steyn 747 ( PRE!) ; Bushmanland. Farm Droëgrond, ca. 45 km southwest of Kakamas, 942 m, (2920 AA), 9 March 2006, Bester 6614 ( KMG!, PRE!) ; Kenhardt District. Farm: Brypaal, ca. 65 km southwest of Kakamas , 867 m, (2920 AB), 10 March 2006, Bester 6668 ( PRE!) ; Kenhardt District. Farm: T’Oubeep, portion A, 898 m, (2920 AC), 13 March 2006, Bester 6783 ( KMG!, PRE!) ; Kenhardt District. Farm Sandkolk, 90 km south of Kakamas ; ca. 1 km directly south of homestead towards Kenhardt / Pofadder road, 898 m, (2920 AD), 11 March 2006, Bester 6687 ( KMG!, PRE!) ; 153 km from Pofadder on road to Kenhardt. (42 km from Kenhardt .), (2920 DA), 18 November 1995, Koekemoer 1072 ( PRE!) ; Kenhardt Div .; 6 mi. W of town, (2921 AC), 15 May 1961, Schlieben 8840 ( M!, NBG!, PRE!, Z!) ; Kenhardt Div .; on farm 10 km. W of Kenhardt , (2921 AC), 10 June 1977, Smook & Harding 761 ( PRE!) ; Kenhardt Div .; 19 mi. ENE of town, 3000 ft, (2921 AD), 14 September 1961, Leistner 2321 ( KMG!, M!, PRE!) ; Kenhardt District. Farm Rooiput, between Putsonderwater and Kenhardt , 1004 m, (2921 BA), 3 April 2010, Steyn 1756 ( PRE!) ; Kenhardt Div .; Angelierspan 40 mi. from Marydale , (2921 DA), 13 May 1946, Story 1150 ( PRE!) ; Niekerkshoop . The Asbestos hills, (2922 AD), May 1921, Vermeulen KMG 1532 ( KMG!) ; Griquatown Dist; Niekerks Hope ; Blaauwboschputs Farm S of Niekerks Hope, 3000 ft, (2922 BD), 20 April 1920, Bryant J 90 ( PRE!) ; Hay Div.; Niekerkshoop ; top of Jasper Mt. few mi. S of Niekerkshoop, (2922 BD), 28 October 1936, Hafström 1151 ( PRE!) ; Prieska , (2922 DA), 26 July 1969, Kerfoot K 6333 ( J!) ; Prieska ; commonage, (2922 DA), 12 July 1920, Bryant J74 ( PRE!) ; Prieska Div .; 3 mi. N by W of Prieska slopes, 3450 ft, (2922 DA), 13 May 1961, Leistner 2290 ( KMG!, M!, PRE!) ; Prieska Div .; 2 mi. NW of town, (2922 DA), 13 May 1961, Schlieben 8767 ( M!, PRE!, Z!) ; Prieska , (2922 DA), March 1934, Wilman KMG 3046 ( KMG!) ; Prieska District, 15 km from Prieska on road from Niekerkshoop , 1073 m, (2922 DB), 3 April 2000, Balkwill, McDade 11763 ( J!) ; 5 km from Prieska on Niekerkshoop road, (2922 DB), 7 June 1977, Smook & Harding 689 ( PRE!) ; Prieska District ; 4.9 km N of bridge on road from Prieska to Niekerkshoop , 919 m, (2922 DB), 3 September 2013, Steyn 1915 ( PRE!) ; Asbestos Mountains , (2923 A), July 1894, Marloth 2032 ( PRE!) ; Asbestos Mountains, Kloof , (2923 AA), September 1811, Burchell 1654 ( K!) ; Herbert Division, Katlani & Reads Drift , (2923 AB), April 1923, Anderson SAM26923 ( SAM in NBG!) ; Hay Div.; Lanyon Vale, (2923 AC), 11 March 1937, Acocks 1971 ( KMG!, M!, PRE!) ; Garies ; on track between Buffelsfontein and Doornkraal , 491 m, (3018 CA), 22 August 2009, Steyn 1681 ( PRE!) ; Fraserburg Div.; Layton , 4500 ft, (3221 BB), 8 August 1965, Shearing 58 ( PRE!) ; Merweville: Fraserburg, Layton , Middlewater / Perdeberg grid, 3000 ft, (3221 BB), 20 July 1992, Shearing A71 ( NBG!, PRE!) ; Western Cape: Prince Albert Dist .; 10 km beyond Prince Albert Road on road to Merweville , (3221 DC), 7 December 1976, Venter 1434 ( PRE!) ; Beaufort West Div .; Fraserburg Road , (3221 DD), July 1935, Broom TRV 33561 ( PRE!) ; Laingsburg , 3000 ft, (3320 BB), February 1918, Thode STEU2700 ( NBG!) ; Farm Rondekop, W of Buffels River. SW of Laingsburg. 33°14’46.7”S 20°52’13.4”E, (3320 BB), 21 May 2009, Snijman 2334 ( NBG!) ; Laingsburg Div.; near Ketting Station ; to S., 2200 ft, (3321 AB), 19 September 1953, Acocks 17139 ( PRE!) ; Koup. Laingsburg , (3321 AB), 24 January 1941, Bond 841 ( NBG!) ; Prince Albert District ; ± 15 km W of Prince Albert on dirt road to Gamkapoort Dam , (3321 BB), 3 September 2013, Steyn 1900 ( PRE!) ; Gamka-Poort Nature Reserve, Southern Karoo: Witpoort , northeast section, along track leading south from entrance gate, 1600 ft, (3321 BC), 2 November 1982, Cattell & Cattell 215 ( NBG!) ; Prince Albert District ; ± 25 km N of Prince Albert on dirt road to Leeu Gamka , 500 m, (3322 AA), 3 September 2012, Steyn 1895 ( PRE!) ; Prince Albert, (3322 AB), May 1907, Marloth 4479 ( NBG!, PRE!) ; Prince Albert, Farm Tierberg , Tierberg, N slope, 33°08’2.3”S 22°16’52.9”E, (3322 AB), 31 August 2006, Roux 4171 ( NBG!). Without specific locality: Lichtenstein s.n. ( GZU000259883 , fragment scan!) ; Thorne SAM59171 ( SAM in NBG!) .

6. Acanthopsis disperma Nees in Candolle (1847: 278); Anderson (1864: 36); Clarke (1901: 34); Meyer (1961: 21); Le Roux (2005: 255); Mannheimer et al. (2008: 218), pro parte; Balkwill (2012: 257); Snijman (2013: 163) ( Figs. 1 , 3F , 9 )

Type: —[ SOUTH AFRICA. Northern Cape:] Afr. Austr.: Zwischen Natvoet und Garip. [ Annotation in Clarke’s handwriting: Between Holgat R. & Gariep R. alt 1000–1500 feet, Little Namaqualand], (2816D), September 1830, Drège s.n. (lectotype K000394340 ! designated here; iso-lectotypes BM000810291 scan!, K000394341!, P04426149!, P04426150!, P04426151!, S-G-40 scan!) .

Acanthodium dispermum E.Mey. in Drège (1837: 2), nom. nud.

Acanthodium dipsaceum E.Mey. in Drège (1843: 92), nom. nud.

Spiny, acaulescent herb up to 100 mm tall. Leaves tufted, arranged in a rosette, obovate to broadly lanceolate (30–)40– 60(–150) × 10–20 mm; cotyledons in seedlings reniform (strikingly different from ordinary leaves); leaf margin flat or undulate, spinose, spines fine, up to 2(3) mm long; with appressed, strigose or spreading hairs; apex rounded to acute; base attenuate; petiole 3–10 mm long, usually without prominent tufts of long, silky hairs at the base. Inflorescences 1–5 per plant, 20–60(–100) mm long, (12–)13–15(–20) mm in diameter, persisting after plant has died. Bracts fan-shaped, 15–20 mm long, base 4–5 mm long; middle and upper bracts ending in 5 primary spines, central primary spine always compound (with 2 or 3 pairs of marginal secondary spines), lateral primary spines with 1 or 2 basal and 3–5 marginal secondary spines; spine tips often tinged purple-brown; primary spines usually recurved and secondary spines spreading in fruit; bract base hirsute to pubescent with deflexed to spreading short hairs and some scattered long hairs, with ring of long, silky hairs adaxially at base of spines; spines almost glabrous with margin of rigid, long hairs and sessile/sub-sessile glands, or pubescent to villose (long, silky hairs interspersed with deflexed short hairs and sessile/sub-sessile glands). Bracteoles sickle-shaped, 7–9 mm long, silky hairy. Calyx tips often almost glabrous, with long silky hairs towards base; dorsal sepal ovate, cuspidate, (10–)11(–14) mm long, densely silky hairy, especially adaxially, 7–9-veined from base; ventral sepal ovate, 9–11 mm long, densely silky hairy, especially adaxially, 5–7- veined from base; lateral sepals 7–8 mm long, densely silky hairy on both sides. Flowers blue-purple with white throat; corolla 19–22(–28) × 7–9(–12) mm, tube (5–)6–9(–11) mm long; central lobe longer than wide or equal, slightly constricted at base, truncate to emarginate. Stamens with purple-black anthers, 2 mm long, filaments 4–5 mm long, sparsely glandular, hairy towards base. Style with patch or ring of glandular hairs at base. Capsules ovate in face view, flattened, glabrous, shiny, 5–7 × 3–4 mm, 2-seeded. Seeds (3–)5 × 3 mm, covered with long white hygroscopic hairs.

Etymology: —The epithet disperma refers to the two-seeded capsule (1 seed per locule).

Distribution, ecology and phenology: — Acanthopsis disperma is centred in the Gariep Centre of Endemism ( Van Wyk & Smith 2001) and occurs in southern Namibia and the bordering Richtersveld, Northern Cape, South Africa ( Fig. 1 ). It is found in the transitional zone between winter- and summer-rainfall regions (either falling in early winter or late summer) in the Succulent Karoo and Nama-Karoo Biomes ( Rutherford & Westfall 1994, Low & Rebelo 1996) or partly also in the Desert Biome of Mucina & Rutherford (2006). The plants prefer weathered granite or quartzite and are found in sandy and gravelly soils on plains and hill slopes at elevations of 65–1200 m with a mean annual rainfall of 20–100 mm per year. Metelerkamp 407 (BOL) noted that the plants are grazed and that the Afrikaans vernacular name volstruisvoet (“ostrich foot”) is presumably derived from one tuft (inflorescence) being smaller than the other. Flowering time: mainly April–September.

Conservation status: — Acanthopsis disperma is a widespread and common species, and is therefore classified as Least Concern (L. von Staden, pers. comm. 2014).

Notes: — Acanthopsis disperma is an acaulescent annual herb with thick, dense inflorescences and differs from A. hoffmannseggiana in not having long, viscid glandular hairs on the bracts and with a more westerly distribution, and from A. adamanticola in its non-glaucous appearance with a more easterly distribution. Although the hairiness of leaves and bracts is fairly variable, the plants retain their annual, acaulescent habit. Plants with glabrous or almost glabrous bracts are found in the winter-rainfall areas where rainfall usually coincides with lower temperatures, while the form with velvety to villose bracts (hairy bract form) is predominantly associated with the northern and eastern parts of the species’ range which falls in the late summer-rainfall part of the Nama-Karoo Biome (warm temperatures in the rainy season) (Steyn & Condy in press).

Kerfoot 5915 (NBG!) bears the locality “Pilaarsberg, N of Pakhuis Pass”. If correct, this would be the only record of Acanthopsis disperma for the Western Cape, and a long way outside the currently accepted distribution range of the species. This specimen is most probably mislabelled as the label also states “heads of dull buff to orange flowers”, and it has therefore been excluded. Niven 25 cited by Clarke (1901) from the Groot (Gamtoos) River [probably Gariep River] could not be traced and has also been excluded.

Acanthodium dispermum E.Mey. var. villosa Schinz (1890: 201) and Blepharis acaulis Lindau (1913: 403) (see Vollesen 2000) were omitted as synonyms of A. disperma , as their type specimens could not be traced and verified.

Additional specimens examined: — NAMIBIA . Karas: Aus, Municipal Campsite , rocky outcrop, sandstone, 1611 m, (2616 CB), 7 August 2001, Bartsch SB384 ( PRE!, WIND!) ; Aus , 1400 m, (2616 CB), 11 January 1910, Dinter 1136 ( SAM in NBG!) ; Hang hinter dem Wohnhaus d. Farm Plateau bei Aus , 1500 m, (2616 CB), 21 May 1954, Kraeusel 853 ( M!) ; In front of homestead of Farm Plateau , LU 38, (2616 CB), 8 September 1963, Kraeusel & Wiss 2013 ( WIND!) ; Farm Plateau , (2616 CB), Merxmüller & Giess 3018 ( M!) ; Auf Quarzit vor Aus in Richtung Helminghausen [Helmeringhausen], (2616 CB), 1956, Volk 12818a ( M!) ; Namib north of Aus , (2616 CB), 28 May 1956, Volk 12819 ( WIND!) ; Farm Plateau, locality of succulents on ‘ Block’ plain, (2616 CB), 13 April 1953, Walter 2551 ( M!, WIND!) ; Farm Aar , in river, (2616 DA), May 1979, Wendt 100 ( WIND!) ; Kuibis , 1350 m, (2616 DB), February 1910, Range 828 ( SAM in NBG!) ; 7 km from Keetmanshoop on road to Goageb , on southern slope of koppie, (2617 DD), 10 May 1976, Müller 267 ( WIND!) ; Sandykop ( LUS 94 ) Lehmfläche unterhalb Schwarzkalkrücken mit Aloe pachygaster , (2716 AD), 16 September 1972, Merxmüller & Giess 28479 ( M!) ; Road from Aus to Rosh Pinah , just past Witputz , 1040 m, (2716 DA), 2 August 2002, Maggs GM2012 ( PRE!, WIND!) ; Farm Kolke : LU 84 ; quartzite koppie on mountain slope near homestead, in coarse rocks, (2716 DB), 11 June 1976, Giess & Müller 14335 ( M!, WIND!) ; On the farm Kolke , NE of Rosh Pinah, 1252 m, (2716 DB), 16 August 2012, Koekemoer 4315 ( PRE!) ; Diamond Area no 1 ; Rosh Pinah ; 6 km W at entrance gate to Diamond Area , (2716 DC), 1 September 1989, Van Wyk 8938 ( PRE!, PRU!) ; Richtersveld National Park. Rosh Pinah , W van vliegveld, (2716 DD), 1 September 1989, Zietsman 1828 ( NMB!, WIND!) ; Wegdraai, Hottentots Plateau , 799 m, (2717 CB), 7 May 2002, Helary & Batault 210 ( WIND!) ; Huns Mountains, 8.5 km upstream of Boomriver mouth, (2717 CC), 17 June 1993, Ströhbach 477 ( WIND!) ; Karasburg District: Fish River Canyon , (2717 DA), 3 August 1979, Owen-Smith 1241 ( WIND!) ; Fischfluss-Canyon , (2717 DA), 29 March 1953, Walter 2288 ( M!) ; Farm Holoogberg: KEE 107. Coarse sand plain with Stipagrostis brevifolia stands, (2717 DB), 17 June 1976, Giess & Müller 14443 ( WIND!) ; Warmbad Dist.; lower Fish River ; Kanibis-Aiais , 800 m, (2717 DC), August 1909, Marloth 4801 ( PRE!) ; Klein Karas, (2718 CA), October 1913, Dinter 3225 ( SAM in NBG!) ; Klein Karas, (2718 CA), 3 August 1923, Dinter 4828 ( PRE!, SAM in NBG!) ; Great Namaqualand; Klein Karas, (2718 CA), 9 April 1931, Ortendahl 48 ( PRE!) ; 20 mil. S of Grunau, Kälkgeroll, Fläche , (2718 CC), 14 May 1963, Bleissner 252 ( M!) ; Sperrgebiet 1—border ; 5 km north of Orange River at Sendelingsdrift , on mountain slope, common, (2816 BB), 12 June 1976, Giess & Müller 14372 ( M!, WIND!) ; Loreley Copper Mine , very weathered schist, (2816 BB), 22 February 1963, Giess, Volk & Bleissner 5415 ( M!, WIND!) ; ca. 40 km from Aussenkehr on road to Sendelingsdrif , (2817 AA), 3 July 2013, Steyn 1904 ( PRE!) ; Southern Namibia : Orange River Valley ; 17.5km below Fish / Orange confluence, 65 m, (2817 AA), 14 September 1988, Ward 10330 ( PRE!, WIND!) ; Between Sendelingsdrift and Rosh Pinah. On the floodplain at the foot of the mountain, 258 m, (2817 AB), 15 August 2012, Koekemoer 4314 ( PRE!) ; 6 km north along Ai-Ais 4×4 Trail from road C13 ( Rosh Pinah-Noordoewer ) on Orange River , 180 m, (2817 AD), 17 October 2005, Kolberg & Tholkes HK 1721 ( WIND!) ; Slopes between Modder Drift and Sjambok River, (2817 CB), September 1931, Pillans 6456 ( BOL!) ; Warmbad Dist.; Norachas WAR 14 Farm , (2818 AA), 14 May 1963, Giess, Volk & Bleissner 6901 ( M!, PRE!, WIND!) ; Warmbad Dist.; Haib River , 600 m, (2818 AC), June 1929, Marloth 13243 ( PRE!) ; Warmbad Dist.; Witputs WAR 258 Farm, (2818 CA), 15 May 1963, Giess, Volk & Bleissner 6949 ( M!, PRE!, WIND!). SOUTH AFRICA. Northern Cape: Richtersveld National Park , (2816 BB), 6 July 1993, Bezuidenhout 566 ( NMB!) ; Sendelingsdrif , (2816 BB), 25 August 1982, Metelerkamp 407 ( BOL!) ; Sides of Kodas River , (2816 BB), October 1926, Pillans 5492 ( BOL!) ; Richtersveld National Park. Between Sendelingsdrif and Potjiespram , (2816 BB), 10 July 1993, Van Rooyen 2279 ( PRU!) ; Richtersveld. Koeboes , (2816 BD), 29 September 1930, Herre STEU12499 ( NBG!) ; Richtersveld ; Noemees , (2816 BD), 6 October 1991, Koekemoer 923 ( PRE!) ; Richtersveld National Park ; hill near Numees mine, 394 m, (2816 BD), 13 July 2011, Koekemoer 4187 ( PRE!) ; Richtersveld. At the foot of Cornellskop , 125 m, (2816 BD), 1 September 2012, Koekemoer 4364 ( PRE!) ; Richtersveld National Park. Noemeesberg , (2816 BD), 14 September 1985, Zietsman & Zietsman 750 ( NMB!) ; Richtersveld National Park. Noemeesberg , (2816 DB), 1 October 1991, Zietsman 2064 ( NMB!) ; Namaqualand District. Richtersveld National Park. Between Potjiespram and De Hoop , (2817 AA), 11 September 2010, Steyn 1811 ( PRE!) ; Richtersveld. Maerpoort , (2817 AA), 7 August 1991, Van Jaarsveld 11762 ( PRE!) ; Richtersveld National Park. De Hoop , (2817 AA), 1 October 1991, Zietsman 2130 ( NMB!, PRU!) ; Namaqualand : Richtersveld ; N foot of Claim Peak. 28°19’S, 17°9’E, 500 m, (2817 AC), 29 October 1972, Bremer 417 ( PRE!) ; Richtersveld. Helskloof. Noisabis , (2817 AC), 3 October1930, Herre STEU13095 ( NBG!) ; Richtersveld ; in the Zebra Kloof; just NE of Rosyntjieberg , (2817 AC), 9 October 1991, Germishuizen 5570 ( PRE!) ; Richtersveld National Park. Near Hakiesdoring Camp on quartzite ridge, 327 m, (2817 AC), 11 July 2011, Koekemoer 4183 ( PRE!) ; Namaqualand District. Richtersveld National Park. Between Gannakouriep Camp and Helskloof turn-off, (2817 AC), 13 September 2010, Steyn 1814 ( PRE!) ; West foot of Rosyntjieberg. Stony plateau, 500 m, (2817 AC), 30 August 1977, Thompson & Le Roux 183 ( NBG!, PRE!) ; Port Nolloth Dist .; Namakwaland, Richtersveld 12 myl S van Grasdrif , 1800 ft, (2817 AC), 17 May 1972, Van der Westhuizen 236 ( PRE!) ; Richtersveld National Park.At Kokerboomkloof camping site, (2817 AC), 30 August 2010, Zietsman & Zietsman 4754 ( NMB!) ; Richtersveld. Tatasberge , (2817 AD), 2 October 1930, Herre STEU13096 ( NBG!) ; Namaqualand District. Richtersveld, Sunvalley camp site, 551 m, (2817 CB), 8 August 2011, Steyn 1845 ( PRE!) ; Namaqualand District. Richtersveld, between Sunvalley turn-off and camp site, 520 m, (2817 CB), 8 August 2011, Steyn 1852 ( PRE!) ; Namaqualand District. Richtersveld, track to Rosynebos N of Basterfontein, 445 m, (2817 CB), 9 August 2011, Steyn 1855 ( PRE!) ; Vioolsdrif. Mountain W of the confluence of Stinkfonteinrivier and Orange River , 636 m, (2817 CB), 14April 1986, Van Jaarsveld, Forrester & Jacobs 8437 ( NBG!) ; 13 mi. E of Stinkfontein ( Eksteenfontein ), 1800 ft, (2817 CD), 12 May 1969, Leistner 3380 ( PRE!) ; S of Vioolsdrif at the Swartkop mine, near the farmhouse, 597 m, (2817 DC), 21 August 2012, Koekemoer 4329 ( PRE!) ; Vioolsdrift ; just outside town, (2817 DC), 15 August 1967, Van der Schijff 8177 ( PRE!, PRU!) ; 16 km south of Vioolsdrif , (2817 DC), 2 June 1976, Wisura 3629 ( NBG!) ; Between Henkries and Goodhouse turn-off on road between Concordia and Pella, 490 m, (2818 CC), 23 August 2009, Steyn 1686 ( PRE!) ; Namakwaland District. 69.1 km from P.O. Concordia. On road to Goodhouse , 590 m, (2918 AA), 4 April 2000, Balkwill, McDade & Lundberg 11780 ( J!). Without legible or specific locality: Klaassen , Bartsch & Loots EK1205 ( PRE!, WIND!) ; Range 692 ( SAM in NBG!) ; Wyley s.n. ( TCD!) .

Figures

FIGURE 1. Known distribution of species within the Acanthopsis disperma-hoffmannseggiana complex. A: A. ludoviciana (●) and A. tuba (Δ), B: A. adamanticola (▲), A. disperma (○), A. dispermoides (□), A. hoffmannseggiana (■) and A. villosa (ۗ).

FIGURE 3. Comparison of floral parts in members of the Acanthopsis disperma-hoffmannseggianna species complex (from left to right): bract(s) (abaxial views), bracteoles, calyx (4 sepals) and flower. A. A. tuba. B. A. ludoviciana. C. A. adamanticola. D. A. villosa. E. A. hoffmannseggiana. F. A. disperma. G. A. dispermoides. Note: if two bracts per species are illustrated, the one on the left is from lower down in the same inflorescence. Scale bar = 10 mm. Vouchers:A = Von Staden CNR 9139 (PRE), B = Koekemoer 4370 (PRE), C = Germishuizen 10074 (PRE), D = Koekemoer 4398 (PRE), E = Steyn 1907 (PRE), F = Koekemoer 4187 (PRE), G = Steyn 1912 (PRE).

FIGURE 8. Acanthopsis hoffmannseggiana: morphology. A–C. Habit. D & E. Leaf indumentum. F & G. Bract. H. Calyx. I. Flower (corolla lobes variable colours; throat white or cream). J. Base of style. K. Capsule. L. Seed. Vouchers: D–G = De Winter 3558 (PRE), H = Steyn 1915 (PRE), I, J = Steyn 1895 (PRE), K, L = Smith PRE40539 (PRE). Photograph: M. Koekemoer (B).

FIGURE 9. Acanthopsis disperma: morphology. A–C. Habit. D & E. Leaf indumentum. F & G. Bract. H. Calyx. I. Flower (corolla lobes blue-purple; throat white). J. Glandular hairs at base of style. K. Part of capsule and seed. L. Seed. Vouchers: D = Koekemoer 4183 (PRE), E = Steyn 1686 (PRE), F, G = Drège s.n (K), H, I = Steyn 1845 (PRE), J = Koekemoer 4187 (PRE), K, L = Van der Westhuizen 236 (PRE). Photographs: M. Koekemoer (A–C).