Thesium durum Hillard & B.L.Burtt

Mashego, Kagiso S. & Roux, M. Marianne le, 2018, A taxonomic evaluation of the Thesium confine species complex (Santalaceae), Bothalia - African Biodiversity & Conservation 48 (1), pp. 1-6 : 4-5

2. Thesium durum Hillard & B.L.Burtt

in Notes Roy. Bot. Gard. Edinburgh 41(2): 311 (1983).

Type: SOUTH AFRICA, Eastern Cape: Fetcani Pass, 15 Oct. 1980, Hilliard & Burtt 13136 ( E – digital image!, holo.; K – digital image!, NBG!, NU!, PRE! , S – digital image!, iso.) .

Description: Erect shrub branching above, root structure unknown, 50 mm – 360 mm high; stems relatively thick, 3 mm – 6 mm diam. Leaves scale-like, closely adpressed to stem, imbricate on young twigs, lanceolate, acuminate, 1.5 mm – 2.3 mm × 0.2 mm – 0.6 mm, ciliate margins. Inflorescences axillary, monotelic, of 1- to 4-flowered spikelike cymes (with single flowers sometimes replaced by 3-flowered monochasia), peduncles 6 mm – 85 mm long; involucral bracts present; bracts ovate, acuminate, 1.4 mm – 1.5 mm × 1.2 mm – 1.6 mm, adpressed to flower; bracteoles 2, lanceolate, slightly narrower than bract, acute, 1.4 mm – 1.5 mm × 0.9 mm – 1.2 mm. Flowers white, tubular, subsessile, perianth tube 2.0 mm – 2.5 mm long, lobes ± 1 mm long, densely bearded with white hairs. Stamens inserted at base of perianth tube; filaments 0.1 mm – 0.2 mm, obscured by anthers; anthers 0.3 mm – 0.6 mm long. Style and stigma 0.3 mm – 0.5 mm long, stigma almost reaching to top of anthers. Placental column twisted. Fruit ellipsoid, brown, with 10 longitudinal ribbed veins, reticulate between main veins, 2.0 mm – 3.3 mm × 2.4 mm – 3.0 mm, stipe 0.3 mm – 0.5 mm. Flowering time: August to October.

Distribution and ecology: Thesium durum occurs in eastern South Africa and Lesotho, from Bethlehem in Free State province along the KwaZulu-Natal Drakensberg to Cradock in Eastern Cape province and Hanover in Northern Cape province ( Figure 2 ). It grows on mountainous slopes and rocky outcrops in grasslands, in loam.

Diagnostic characters and relationships: Thesium durum differs from T. confine in its erect habit with thicker, woody branches and stems 3 mm – 6 mm diam., and axillary inflorescences with involucral bracts.

Conservation status: Thesium durum is a Least Concern species because it is widespread and abundant ( Foden & Potter 2005a).

Additional specimens seen: SOUTH AFRICA. FREE STATE. – 2828 (Bethlehem): Bethlehem, Golden Gate National Park, Generaalskop, (– BC), 21 Jan. 1965, B.R. Roberts 3432 ( PRE) .

KWAZULU-NATAL. – 2830 (Dundee): Drakensberg, Cathkin Peak, (– AB), 1 Jul. 1950, E. E. Esterhuysen 17354 ( PRE). 2929 (Underburg): Mpendhle, path from Loteni Nature Reserve to Redi on ridge, (– AD), 26 Dec. 1982, O. M. Hilliard 16104 ( PRE, K) ; locality unknown, (– AD), 1 Oct. 1967, F. B. Wright 220 ( NU) ; Mpendhle, Mulangane Ridge, above Carter’s Nek, (– BC), 13 Mar. 1983, O. M. Hilliard 18372 ( PRE) ; Underberg, upper tributaries south of Mkimazi River, (– CB), 30 Nov. 1982, O. M. Hilliard & B. L. Burtt 15715 ( K) .

EARTERN CAPE. – 3027 (Lady Grey): Verge of road up Joubert’s Pass, ± 8 km from Lady Grey, (– CB), 25 Feb. 2007, C. L. Bredenkamp 26 ( PRE) ; about 15 km east of Rhodes: Mavis Bank Farm, on Kloppershoek turn-off, (– DB), 9 Dec. 1999, M. Koekemoer 1559 ( PRE) ; north-east of Rhodes, Kloppershoekspruit Valley, Mavis Bank Farm, mountain on western side of valley from house, (– DB), 9 Dec. 1999, L. Smook 10311 ( PRE) ; Barkly East, 6 mi [9.7 km] north-westof Moshesh Ford, (– DC), 14 Nov. 1959, J. P. H. Acocks 20165 ( PRE) ; locality unknown, (– DC), 2 Nov. 1983, O. M. Hilliard 16360 ( NU) ; west of Rhodes, Maartinshoekspruit Valley, Maartindale Farm, (– DD), 12 Dec. 1999, L. Smook 10399 ( PRE). 3028 (Matatiele): About 15 km east of Rhodes: Mavis Bank Farm ; on Kloppershoek turn-off, (– CA), 8 Dec. 1999, M. Koekemoer 1524 ( PRE) ; Glen Lynden Farm, top of Naude’s Nek Pass, (– CA), 20 Oct. 1994, S. P. Bester 3013 ( PRE) ; northeast of Rhodes, Kloppershoekspruit Valley, Mavis Bank Farm, at house, (– CA), 7 Dec. 1999, L. Smook 10232 ( PRE). 3225 (Somerset East): Cradock, 1.5 mi [2.4 km], south-east of Lexton Springs, (– CB), 3 Jan. 1959, J. P. H. Acocks 20123 ( PRE) .

NORTHERN CAPE. – 3124 (Hanover): Colesberg, 9 mi [14.5 km] east by south of Naauwpoort, (– BB), 30 Oct. 1953, J. P. H. Acocks 17521 ( PRE) .

LESOTHO. – 2927 (Maseru): Mafeteng, Ribaning stream, hillside above stream, (– AD), 22 Oct. 1946, E. E. Esterhuysen 13207 ( PRE) ; mountain road, Leucosidea forest, (– BD), 1 Oct. 1963, M. O. Schmitz 2713 ( PRE) ; moutain road, 5 km before Bushman Pass, (– BD), 2 Nov. 1977, M. O. Schmitz 8030 ( PRE). 2928 (Marakabei): Near Aurey, 45 km east of Blue Mountain Pass on road to Mantsonyane, (– CA), 17 Nov. 1983, A. P. M. de Kruif 1172 ( PRE) ; Orange valley, between Sehlabathebe and Thaba Tseka, (– DB), 29 Oct. 1979, M. O. Schmitz 8859 ( PRE). 2929 (Underburg): Locality unknown, (– CC), 20 Nov. 1983, O. M. Hilliard & B. L. Burtt 16817 ( NU) ; Sehlabathebe National Park, Matsa a Mafikeng, (– CC), 5 Nov. 1976, A. C. Beverly & F. K. Hoener 375 ( PRE). 3028 (Ramatsaliso): Ramatseliso gate (4 km), (– BB), 1 Nov. 1979, M. O. Schmitz 8830 ( PRE) ; locality unknown, (– CC), 13 Nov. 1983, O. M. Hilliard 16621 ( NU) .

Figures

FIGURE 2: Distribution map Thesium confine (circles) and Thesium durum (triangles).