Festuca caprina var. macra Stapf, Fl. Cap. 7: 720. 1900. Festuca macra (Stapf) E.B. Alexeev, Bot. Zhurn. (Moscow & Leningrad) 71(8): 1116. 1986.

Sylvester, Steven P., Soreng, Robert J., Sylvester, Mitsy D. P. V. & Clark, Vincent Ralph, 2020, Festuca drakensbergensis (Poaceae): A common new species in the F. caprina complex from the Drakensberg Mountain Centre of Floristic Endemism, southern Africa, with key and notes on taxa in the complex including the overlooked F. exaristata, PhytoKeys 162, pp. 45-69 : 45

Festuca caprina var. macra Stapf, Fl. Cap. 7: 720. 1900. Festuca macra (Stapf) E.B. Alexeev, Bot. Zhurn. (Moscow & Leningrad) 71(8): 1116. 1986. Fig. 5 , Table 1

Type.

South Africa. [Kalahari Region: Orange Free State:] Wittebergen, near Harrismith, Comm. O. MacOwan, Feb 1877, Buchanan 262 (holotype: K (K000345247 [image!]); isotype: PRE! fragm. ex K).

Notes.

Alexeev (1986) raised var, macra to species level and differentiated it from F. caprina based on: a) sheaths of old leaves not falling apart into parallel thin threads (vs. falling apart (shredded) into parallel thin threads in F. caprina , although this is now considered erroneous; see comments under F. caprina above); b) leaf blades more or less glaucous (vs. green in F. caprina ); c) abaxial leaf-blade surfaces scabrous (vs. smooth or scaberulous in F. caprina ); d) adaxial leaf-blade surfaces shortly hairy (vs. scabrous or shortly hairy in F. caprina ); e) lemmas 4.5-5 mm long (vs. 5-7[9] mm long in F. caprina ); f) awns 1.5-3.5 mm long (vs. [0.5]1-4 m long in F. caprina ); g) anthers 1.6-2.2 mm long (vs. [2-]2.5-4 mm long in F. caprina ); h) spikelets straw-coloured-violet (vs. violet-green, rarely green in F. caprina ). However, only the holotype of F. caprina var. macra was seen by Alexeev, as well as original material (from which a lectotype was selected) and a limited number of other specimens of F. caprina var. caprina at the K herbarium.

Upon study of numerous specimens that belong to F. caprina var. caprina and var. macra during extensive fieldwork in the DMC and herbarium study at PRE, it became apparent that the above-mentioned differentiating characters overlap. Both F. caprina var. caprina and F. caprina var. macra share most characteristics, such as intravaginal tillers forming dense, often large, tussocks, with entire, often lustrous, basal sheaths, narrow involute blades and similar inflorescence and spikelet morphology, with anthers usually> 2 mm long. The F. caprina var. macra holotype is on the shorter side with regards most inflorescence characters when compared with F. caprina var. caprina , with shorter spikelets, lemmas, awns and anthers according to the protologue. Nevertheless, most of these characters have also been found in specimens of F. caprina var. caprina , with variability in lengths of the spikelet parts possibly being related to ecological conditions, including seasonal variations in rainfall (C. Mashau, pers. comm.). The anther length of 1.6 mm, mentioned in the protologue for F. macra ( Alexeev 1986: table 2), is shorter than any specimen of F. caprina var. macra studied by us, with it being plausible that the var. macra holotype could be somewhat intermediate between F. drakensbergensis and F. caprina var. macra in its broader sense, with similar plausible hybrids with a mixture of characters sometimes found in the DMC (see below). Indumentum of the adaxial leaf-blade surface was also found to vary between scabrous, long-scabrous with prickles becoming elongated and hair-like and shortly hispid in all the taxa of the F. caprina complex from southern Africa, with this character seen to have no diagnostic value.

Festuca caprina var. macra was not included in the treatment of southern African grasses by Fish and Moeaha (2015), who chose not to uphold any of the varieties of F. caprina stating that the species was too variable. Nevertheless, we consider F. caprina var. macra to be distinct from var. caprina based on the character of notably antrorsely scabrous abaxial leaf-blade surfaces that is not known outside of the DMC, with all other F. caprina specimens across their range being smooth or exceptionally scaberulous towards their apices. Specimens with notably scabrous leaf blades were also found to be geographically and ecologically distinct during fieldwork in the DMC, these being predominantly found in drier alpine areas of the DMC, while var. caprina was found in more mesic environments often at lower elevations in the montane belt.

Plants of the World Online (2020), Plantlist (2020), the World Checklist of Selected Plant Families (2020) and GrassBase ( Clayton et al. 2006 onwards) currently accept F. macra as a distinct species. While we currently disagree with this assessment, more exhaustive research may result in var. macra being raised to subspecies level, with certain characters still needing to be assessed such as lemma micromorphology, which has been proven to be taxonomically informative in Festuca ( Ortúñez and Cano-Ruiz 2013).

Festuca caprina var. macra is often dominant in less-disturbed Afro-alpine grasslands of the DMC ( Carbutt 2019), being found in Lesotho and the Eastern Cape, Free State, KwaZulu-Natal Provinces of South Africa. Of the 222 2 m × 2 m plots studied throughout the DMC, 99 were occupied and often dominated ([0.5-]20-92% of overall plot cover) by F. caprina var. macra (Sylvester et al. unpubl. data), with a total of 42 collections of the species being made. It is more palatable than Merxmuellera Conert species and so is less common in grazed areas (Sylvester and Soreng, pers. obs.).

Festuca obturbans St.-Yves and its allies F. gilbertiana Alexeev ex S.M. Phillipps and F. macrophylla A. Rich., described from Afro-alpine vegetation of Kenya or Ethiopia, also bear superficial similarity to F. caprina var. macra in their intravaginally branched large tussocks with entire basal sheaths and fine, involute and usually scabrid leaf blades ( Alexeev 1986; Phillips 1995a, b). These also share similar inflorescence characteristics with F. caprina var. macra , such as relatively-narrow panicles with spikelets loosely arranged on short ascending branches, and spikelets with similar glume, lemma and anther sizes ( Alexeev 1986; Phillips 1995a, b). These can be differentiated by their leaf blade cross sections showing sclerenchyma girders bridging both sides of the vascular bundles or, at least, the larger ones (vs. sclerenchyma only present on the abaxial blade ribs in F. caprina var. macra ). Festuca gilbertiana can be further differentiated by its smooth leaf blades, culms 30-35 cm tall, and sparse racemose inflorescence (vs. leaf blades scabrous, culms (28-)60-110(-120+) cm tall, inflorescence usually a large loosely-contracted panicle in F. caprina var. macra ). Festuca obturbans can be further differentiated by having sheaths open to almost their base and ovary apices glabrous (vs. sheaths closed for ca. ½ their length, ovary apices sparsely to densely pubescent in F. caprina var. macra ).

Two specimens found near the Tiffindell Ski Resort of the Eastern Cape, South Africa (Sylvester et al. 3428B) and Bokong Nature Reserve, Lesotho (Sylvester et al. 3687B), bore characteristics of F. caprina var. macra , which was collected alongside them (Sylvester et al. 3428A, 3687C), such as tussock-forming habit with intravaginal branching and entire basal sheaths not splitting into fibres. However, they differed by their smooth abaxial leaf blade surfaces, placing them closer to F. caprina var. caprina , unawned lemmas, which is unusual for both var. caprina and var. macra , and short spikelets with lowermost lemmas 4.5-5.8 mm long anthers measuring ca. 1.6-1.8 mm long, placing them closer to F. drakensbergensis . As F. drakensbergensis was also collected at the same localities (e.g. Sylvester et al. 3459, 3687B), it is plausible that these could be hybrids between F. caprina var. macra and F. drakensbergensis . More study, including further collections, is required to ascertain the identity of these specimens.

Selected specimens examined.

Lesotho. AfriSki area, in valley adjoining and northwest of the valley of the AfriSki resort, on the north side of the A1 highway, 28.808394S, 28.708658E, 3104 m alt., dry upper slopes above valley, 27 Feb 2020, S.P. Sylvester et al. 3652 (NU, PRE, US); AfriSki resort, in valley just west of the resort centre, 28.822906S, 28.724602E, 3046 m alt., relatively undisturbed damp Afro-alpine grassland, 28 Feb 2020, S.P. Sylvester et al. 3663 (PRE, US); Bokong Nature Reserve, ca. 350 m north from the information centre, 29.067203S, 28.421496E, 2972 m alt., Afro-alpine grassland dominated by Lachnagrostis barbuligera var. barbuligera with moderately-controlled grazing and burning, 2 Mar 2020, S.P. Sylvester et al. 3687b (US); S.P. Sylvester et al. 3687c (US); Matebeng Pass, below highest summit close to the pass, 29.870708S, 28.976534E, 3094 m alt., "Lesotho Highland Basalt Grassland" with clear elements of "Drakensberg Afro-alpine Heathland" with Erica and Helichrysum shrubs dominating the landscape, 22 Feb 2020, S.P. Sylvester et al. 3576 (US); Matebeng Pass, below highest summit close to the pass, 29.868524S, 28.976439E, 3125 m alt., Afro-alpine vegetation with Ericaceous shrubs dominating the landscape, heavy grazing, 22 Feb 2020, S.P. Sylvester et al. 3580 (US); Matebeng Pass, below highest summit close to the pass, 29.873765S, 28.976929E, 2947 m alt., Afro-alpine vegetation with Ericaceous shrubs dominating the landscape, heavy grazing, 22 Feb 2020, S.P. Sylvester et al. 3588 (PRE, US); Menoaneng Pass, on road between Rafolatsane and Thaba-Tseka, 29.427317S, 28.950617E, 3039 m alt., Afro-alpine grassland, windy ridge, grazed, 24 Feb 2020, S.P. Sylvester et al. 3601 (US); Sani Pass area, ca. 800 m east of Sani Mountain Lodge, 29.585198S, 29.292011E, 2896 m alt., short Afro-alpine grassland, frequently to heavily grazed, 25 Feb 2020, S.P. Sylvester et al. 3619 (PRE, US); S.P. Sylvester et al. 3620 (US); Sehlabathebe National Park, lower end of the Park on the border, 29.859882S, 29.095598E, 2779 m alt., wet Afro-alpine tussock grassland, soil damp, under dripping crag, heavily grazed, close to livestock paths, 19 Feb 2020, S.P. Sylvester et al. 3523 (NU, PRE, US); Sehlabathebe National Park, lower end of the Park on the border, 29.860180S, 29.095586E, 2733 m alt., wet Afro-alpine tussock grassland, soil damp, under dripping crag, heavily grazed, close to livestock paths, 19 Feb 2020, S.P. Sylvester et al. 3538 (PRE, US). South Africa. Eastern Cape: between Carlisleshoekspruit Pass and Tiffindell Ski Area, 30.6852485S, 27.963802E, 2565 m alt., Afro-alpine grassland, 10 Feb 2020, S.P. Sylvester et al. 3428a (PRE, US); Eastern Cape: between Carlisleshoekspruit Pass and Tiffindell Ski Area, 30.6852485S, 27.963802E, 2565 m alt., Afro-alpine grassland, 10 Feb 2020, S.P. Sylvester et al. 3428b (NU, PRE, US); Eastern Cape: Tiffindell Ski Area, 30.649239S, 27.928720E, 2845 m alt., Afro-alpine grassland, 10 Feb 2020, S.P. Sylvester et al. 3446 (NU, PRE, US); Eastern Cape: Tiffindell Ski Area, 30.676006S, 27.958567E, 2527 m alt., Afro-alpine tussock grassland, 12 Feb 2020, S.P. Sylvester et al. 3480 (NU, PRE, US); Eastern Cape: Tiffindell Ski Area, Ben Macdhui summit, 30.648172S, 27.935507E, 2998 m alt., Afro-alpine grassland, 11 Feb 2020, S.P. Sylvester et al. 3462b (NU, PRE, US); Eastern Cape: Tiffindell Ski Area, next to ski lift, 30.651034S, 27.925149E, 2778 m alt., Afro-alpine grassland, annually burnt, appears to be seeded with exotic species, 11 Feb 2020, S.P. Sylvester et al. 3463 (NU, PRE, US); KwaZulu-Natal: Amphitheatre, slopes near the Tugela waterfall, 28.754008S, 28.893853E, 2983 m alt., Afro-alpine grassland, 5 Feb 2020, S.P. Sylvester et al. 3403 (NU, PRE, US); KwaZulu-Natal: Amphitheatre, slopes near the Tugela waterfall, 28.753989S, 28.893563E, 2979 m alt., Afro-alpine grassland, 5 Feb 2020, S.P. Sylvester et al. 3406 (US); KwaZulu-Natal: Amphitheatre, slopes near the Tugela waterfall, 28.750810S, 28.888942E, 2981 m alt., Afro-alpine grassland, 5 Feb 2020, S.P. Sylvester et al. 3409b (US).

Figures

Figure 5. Festuca caprina var. macra. A Whole plant B abaxial leaf blade surface of tiller C spikelet, lateral view. Images of S. P. Sylvester et al. 3480 (US).