Introduction

Anthoxanthum L. is a genus of temperate C3 grasses with ± 20 species throughout the world (Gibbs Russell et al. 1990; Fish 2000). The genus is most diverse in the temperate regions of the northern hemisphere, especially Asia, from where it extends southwards through the African mountains (Afromontane Region) with a secondary centre of diversity in southern Africa (±4 species in southern Africa and 1 naturalised). The main objective of this paper is to describe a new subspecies of Anthoxanthum from southern Africa, to present a synopsis of the genus and determine additional characters to define species in the region. Specimens from the National Herbarium (PRE) were examined.

Stapf (1899) described three species for southern Africa namely Anthoxanthum dregeanum (Nees) Stapf, A. ecklonii (Nees ex Trin.) Stapf and A. tongo (Trin.) Stapf. All are endemic to southern Africa, except A. ecklonii which is widely distributed in southern Africa. During a taxonomic treatment of the genus a new subspecies was identified, which in the present contribution is described, illustrated and compared with similar members of the genus.

Taxonomic Treatment

Anthoxanthum L., Species Plantarum: 28 (Linnaeus 1753). Type species: Anthoxanthum odoratum L.

An annual or perennial, tufted to decumbent; stoloniferous or rhizomatous; sometimes aromatic. Leaf blade linear, expanded and often folded; ligule an unfringed membrane. Inflorescence a narrow, spike-like panicle; spikelets solitary, sessile or pedicelled. Spikelet moderately laterally compressed, disarticulating above the glumes; glumes unequal, similar, membranous with hyaline margins, glabrous to hairy, awnless; lower glume 1 – 5-nerved; upper glume 3-nerved. Florets 3, lower 2 florets male or sterile with lower lemma(s) longer than the uppermost lemma, membranous, hairy, 5 – 7-nerved, apex 2-lobed, lowest lemma with a short straight awn from above middle of the back, second lemma awned from near the base, awn geniculate; uppermost floret bisexual, lemma glabrous, awnless; palea without keels, usually 1-nerved. Lodicules 0. Stamens 2 or 3 (rarely). Ovary glabrous; styles long, plumose. Caryopsis hilum short; embryo small.

photosynthetic pathway. C3; XyMS+.

cytology. x = 5 (polyploidy).

species. ± 20. North temperate regions of the world and the mountains of tropical Africa. Apart from the African species, the genus is found in Europe, Asia and North America; ± 4 in southern Africa (1 naturalised), Lesotho, South Africa: Mpumalanga, Free State, KwaZulu-Natal, Eastern and Western Cape.

Key to species

  • 1. Lower glume 1-nerved…………………………………………………………………… 2

  • Lower glume 3 – 5-nerved …………………………………………………………….… 5

  • 2. Glumes subacuminate; lower lemma not densely hairy, pilose or hairs somewhat shaggy …………………………………………………………………………..1. A. brevifolium

  • Glumes acute to acuminate; lower lemma densely or sparsely hairy …………………… 3

  • 3. Lower lemma 3.0 – 3.5 mm long, always dark brown, densely hairy; anther 4.0 – 4.5 mm long ………………………………………………………………………..4. A. odoratum Footnote 1

  • Lower lemma 3.5 – 5.0 mm long, pale to light brown, usually sparsely hairy; anther 2.0 – 2.3 mm long……………………………………………………………………………… 4

  • 4. Lower glume 5.0 – 6.0 mm long; lower lemma 5.0 mm long; spikelet length 6.0 – 8.5 mm long .……………………….….. 3a. A. ecklonii subsp. ecklonii

  • Lower glume 3.5 – 4.0 mm long; lower lemma 3.5 – 4.5 mm long; spikelet length 5.2 – 6.5 mm long ………………………………………………3b. A. ecklonii subsp. natalense

  • 5 (1). Inflorescence small, oblong, contracted or reduced to a scanty raceme; plant delicate and weak, straggling to loosely tufted; leaves soft …………………………………5. A. tongo

  • Inflorescence spike-like, fairly dense, occasionally interrupted near the base; plant usually distinctly and densely tufted and erect; leaves usually rigid and pungent ……… …………………………………………………………………………..2. A. dregeanum

1. Anthoxanthum brevifolium Stapf (1910: 59). Type: South Africa, Eastern Cape: Barkly East Division; on Ben McDhui (Wittebergen), 2955 m, Galpin 6884 (holotype PRE!; isotypes: BOL, photo!; K, photo!).

Tufted rhizomatous perennial 150 – 220 mm high; leaves crowded at the base. Leaf blade up to 37.5 × 5.6 mm, short, broad, apex blunt. Inflorescence contracted, spike-like, 30 – 40 mm long. Spikelet 7 mm long; glumes subacuminate, glabrous or scabrid on the back, keels smooth or scaberulous; lower glume 5 mm long, 1-nerved, sub-hyaline; upper glume 7 mm long, 3-nerved, longer than and enfolding the spikelet; lower lemma 5.5 mm long, 5-nerved, light brown, hairs not dense but somewhat shaggy or pilose; upper floret lemma 2.0 mm long, glabrous, awnless; anther 2.4 mm long.

recognition. This species is known only from the type collection. Except for the very short, broad leaf blades and subacuminate glume, this specimen is difficult to distinguish from Anthoxanthum ecklonii which has acute to acuminate glumes.

distribution. Endemic. South Africa: Eastern Cape.

frequency in southern africa. Rare.

specimen examined. south africa: Eastern Cape: Barkly East Division; on Ben McDhui (Wittebergen), 2955 m, Galpin 6884 (holotype PRE!; isotypes: BOL, photo!; K, photo!).

conservation status. Data deficient — Taxonomically Problematic (DDT) (Victor et al. 2007).

phenology. Flowering March.

2. Anthoxanthum dregeanum (Nees) Stapf (1899: 466). Type: South Africa, Western Cape, "Cape Good Hope".

Hierochloe dregeana Nees ex Trin. (Trinius 1839: 83). Type as above.

Tufted, rhizomatous perennial 200 – 600 mm high. Leaf blade to 250 × 9 mm, linear, usually rigid, often folded, gradually tapering to a pungent point. Inflorescence spike-like, up to 80 mm long, occasionally interrupted near the base. Spikelet 6 to 7 mm long; glumes shortly acuminate, glabrous or minutely hairy on the backs, keels smooth or scaberulous; lower glume 4 – 5 mm long, 3-nerved; upper glume 6 to 7 mm long, 3-nerved, longer than and enfolding the spikelet; lower lemma 4 – 6 mm long, dark brown, hairy; upper floret lemma 2.0 – 3.0 mm long, glabrous, awnless; anther 2.6 – 3.9 mm long.

distribution. Endemic. South Africa: Western Cape.

frequency in southern africa. Infrequent to locally common.

specimens examined. south africa. Acocks 19885; Bolus 14668A, 14668B; Esterhuysen 26575; Liebenberg 4010; Rehm 806; Vlok 1283.

conservation status. Least Concern (LC) (Fish & Victor 2005).

phenology. Flowering Oct. to Jan.

ecology. On moist mountain slopes.

3a. Anthoxanthum ecklonii (Nees ex Trin.) Stapf subsp. ecklonii (Stapf 1899: 466). Type: South Africa, Western Cape, "Cape Good Hope".

Ataxia ecklonis Ness ex Trin. (Trinius 1839: 77). Type as above.

Hierochloa ecklonii Nees (1841: 7). Type as above.

Loosely or densely tufted perennial 350 – 800 mm high; rhizomatous; base of culm usually bulbous. Leaf blade 70 – 250 × 4 – 9 mm, expanded or folded, tapering to a very fine acute point. Inflorescence spike-like, 40 – 130 mm long. Spikelet 6 – 8 mm long; glumes acute to acuminate, glabrous or scabrid on the backs, keels scaberulous; lower glume 5 – 6 mm long, 1-nerved, hyaline; upper glume 6 – 8 mm long, 3-nerved (rarely 1-nerved), sub-hyaline, longer than and enfolding the spikelet; lower lemma 5 mm long, pale to light brown, usually sparsely hairy; upper floret lemma 2.0 – 2.4 mm long, glabrous, awnless; anther 2.0 – 2.3 mm long.

recognition. Resembles Anthoxanthum odoratum, which has the lower lemma shorter (3.0 – 3.5 mm long), dark brown and densely hairy.

distribution. Possibly Malawi. Lesotho, South Africa: Mpumalanga, Free State, KwaZulu-Natal, Eastern Cape and Western Cape.

frequency in southern africa. Infrequent but fairly widespread.

specimens examined. south africa. Acocks 20194; Killick 1296; Moss 1738; Roberts 3297; Smook 1192, 4804.

conservation status. Least Concern (LC) (Fish & Victor 2005).

phenology. Flowering Dec. to April.

ecology. Usually in moist places such as stream sides and on grassy mountain slopes, extending to forest margins.

3b. Anthoxanthum ecklonii (Nees ex Trin.) Stapf subsp. natalense Mashau, subsp. nov. Type: South Africa, Kwazulu-Natal, 2829 (Bergville): Cathedral Peak Forest Research Station (–CD), 17 Nov. 1950, D. J. B. Killick 1132 (holotype PRE!).

http://www.ipni.org/urn:lsid:ipni.org:names:77153655-1

Loosely tufted perennial 300 – 430 mm high; rhizomatous. Leaf blade 60 – 150 × 1.5 – 4.5 mm, expanded or folded. Inflorescence contracted, spike-like, 35 – 90 mm long. Spikelet 5.2 – 6.5 mm long; glumes unequal, acute to acuminate, glabrous, keels scaberulous; lower glume 3.5 – 4.0 mm long, 1-nerved; upper glume 5.2 – 6.5 mm long, 3-nerved; lower lemma sparsely hairy; lowest lemma 3.5 – 4.5 mm long, pale to light brown, awned from ± ½ – 2/3 as long as lemma body; second lemma 3.5 – 4.5 mm long, awned from ± 1/3 as long as lemma body; upper floret lemma 1.5 – 2.0 mm long, glabrous, awnless; anther 1.5 mm long (Fig. 1).

Fig. 1
figure 1

Anthoxanthum ecklonii subsp. natalense. A habit; B spikelet; C lower lemma. D. J. B. Killick 1132 (PRE). photos: A. C. Mashau, specimen scanned by William Sepheka.

Full size image

recognition. Anthoxanthum ecklonii subsp. natalense is similar to A. ecklonii subsp. ecklonii. Both subspecies have glumes with keels scaberulous and lower lemma sparsely hairy, but they differ in a number of characters as summarised in Table 1.

Table 1. Differences between Anthoxanthum ecklonii subsp. natalense and A. ecklonii subsp. ecklonii.
Full size table

distribution. Known only from the broad arc of Drakensberg covering the surroundings of Bergville in the northern side, then south to Impendle and Underberg (KZN) (Map 1).

Map 1
figure 2

Known distribution of Anthoxanthum ecklonii subsp. natalense ●.

Full size image

specimens examined. south africa. kwazulu-natal. 2829 (Bergville): Cathedral Peak Forest Research Station, (–CD), 20 Nov. 1951, Killick 1606 (PRE). 2929 (Escourt): Highmost Forest Station (–BC), 15 Jan. 1966, Killick & Vahrmeÿer 3625 (PRE); (Mpendhle): Mulangane ridge, above Carter’s Nek, (–BC), 5 Feb. 1984, Hilliard & Burtt 17587 (PRE). 2929 (Underberg): Sani Pass, next to the Umkomazana R. (–CB), 18 Jan. 1977, du Toit 2295 (PRE); 5 – 7 miles NNW of Castle View farm, headwaters Mlahlangubo R. (–CB), 23 Jan. 1982, Hilliard & Burtt 15360 (PRE); Cobham Forest Reserve, Lakes cave area (–CB), 12 Dec. 1982, Hilliard & Burtt 15914 (PRE).

conservation status : Not Evaluated.

phenology. Flowering time: Nov. to Feb.

ecology. Anthoxanthum ecklonii subsp. natalense is associated with the Drankensberg Foothill Moist Grassland (Mucina & Rutherford 2006). Plants grow abundantly on mud islands in streams below waterfalls. The area is characterised by mudstones and sandstones of the Tarkastad] Subgroup and the Molteno Formation (Karoo Supergroup) as well as intrusive dolerites of the Jurassic age.

etymology. Anthoxanthum derived from the Greek word ‘anthos’ meaning flower; ‘xanthos’ means yellow, referring to the yellow-green mature spikelets. The species epithet ‘ecklonii’ is in honour of Christian Frederick Ecklon (1795 – 1868) German-born South African apothecary and plant collector. The word ‘natalense‘ denotes the origin of the subspecies, collected from Kwazulu-Natal, South Africa.

4. Anthoxanthum odoratum Footnote 2 L. (Linnaeus 1753: 28). Type: Europe. Sweet vernal grass.

Loosely or densely tufted perennial 300 – 600 (– 1000) mm high. Leaf blade 150 – 300 × 2 – 8 mm, expanded, apex acute to acuminate. Inflorescence spike-like, 10 – 90 mm long. Spikelet 7 – 10 mm long; glumes acute, hyaline, glabrous or minutely hairy on the back, keel scaberulous; lower glume up to 5 mm long, 1-nerved; upper glume 7 – 10 mm long, longer than and enfolding the spikelet; lower lemma 3.0 – 3.5 mm long, always dark brown, densely hairy; upper floret lemma 1.5 – 2.0 mm long, glabrous, awnless; anther 4.0 – 4.5 mm long.

recognition. Anthoxanthum odoratum resembles A. ecklonii, which has the lower lemma longer (5 mm long), lighter coloured and sparsely hairy.

distribution. Naturalised from Europe. Introduced in North and South America, Australia, Tasmania and New Zealand. South Africa: KwaZulu-Natal and Eastern Cape.

specimens examined. south africa. Acocks 22118; Moll 1386; Phillipson 906.

frequency in southern africa. Locally common.

conservation status. Not Evaluated.

phenology. Flowering Oct. to Feb.

ecology. Humic soils in moist, swampy areas.

uses. Introduced as a fodder grass to some countries. Fresh plant smells of coumarin.

5. Anthoxanthum tongo (Trin.) Stapf (1899: 467). Type: South Africa, Western Cape, "Cape Good Hope".

Ataxia tongo Nees ex Trin. (Trinius 1839: 78). Type as above.

Hierochloe tongo (Nees ex Trin.) Nees (1841: 71). Type as above.

Straggling or loosely tufted perennial 100 – 400 mm high; culm very fine; occasionally mat-forming. Leaf blade 20 – 100 (– 170) × 2 mm, flat or folded, filiform to setaceous. Inflorescence small, up to 35 mm long, oblong, contracted or reduced to a scanty raceme, with very few spikelets. Spikelet 5 – 7 mm long; glumes acute, glabrous or pilose on the back; lower glume up to 5 mm long, 3 – 5-nerved; upper glume 5 – 7 mm long, 3-nerved, longer than and enfolding the spikelet; lower lemma ± 4 mm long, creamy white to light brown, densely hairy; upper floret lemma 1.8 – 2.3 mm long, glabrous, awnless; anther 2.5 – 3.2 mm long.

distribution. Endemic. South Africa: Western Cape.

frequency in southern africa. Locally common.

specimens examined. south africa. Acocks 23021; Ellis 5146; Esterhuysen 28443, 33603; Kruger 815; Rycroft 712.

conservation status. Least Concern (LC) (Fish & Victor 2005).

phenology. Flowering Sept. to Feb.

ecology. In moist shady places in the shelter of rocks and in shallow crevices.