Tetradenia discolor Phillipson, 2008

Phillipson, Peter B. & Steyn, Catherine F., 2008, Tetradenia (Lamiaceae) in Africa: new species and new combinations, Adansonia (3) 30 (1), pp. 177-196 : 182-184

3. Tetradenia brevispicata (N.E.Br.) Codd

Bothalia 14 (2): 179 (1983) ; Codd , Flora of Southern Africa 28: 114 (1985). — Iboza brevispicata N.E.Br. , in Thiselton-Dyer (ed.), Flora Capensis v. I.: 302 (1910). — Type: South Africa, Wonderboom Farm near Pretoria, 6.VIII.1904, Burtt Davy 1844 (holo-, K!).

SELECTED REPRESENTATIVE MATERIAL. — Botswana. South-east district, Ofse, hill E of main road, 18.VIII.1978, Hansen 3435 ( K, PRE, SRGH). — 5 miles SE of Gaborone, 10.VIII.1974, Mott 320 ( K) .

Namibia. Brakwater 10 miles N of Windhoek on rd. to Okahandja , 25.IV.1955, de Winter 3242 ( K, P) . — Stadtgebiet von Klein-Winhoek, Uhlandstrasse, in Glimmerschieferspalten , 7.I.1964, Giess s.n. ( K) . — Otjimbingwe, Farm Kaan dam, Geiss 13523 ( NBG) . — Farm Khomas, 64 km NW of Windhoek, Hardy 6554 ( MO) . — Windhoek district , Avis Dam, Liebenburg 4497 ( K PRE) . — Windhoek region , Schlieben 10416 ( PRE) . — Hindhuker Bergland , 27.IV.1958, Seydel 1525 ( K, MO, SRGH) . — Avis, Windhoek , 4.VI.1961, Seydel 2270 ( K, MO) . — Hindhuker Bergland , 25.III.1963, Seydel 3465 ( K, MO) . — District Windhoek , 14.III.1965, Tolken & Hardy 710 ( K) . — Rietfontein, Windhoek district , Strey 1557 ( PRE) . — 8 miles S of Kapps arm, Wilman 434 ( PRE) .

South Africa. Soutpansberg district , SE of Louis Trichardt , Ben Lavin Nature Reserve , Tabanjwane Hill , Balkwill , Balkwill and Wits Biosoc 4091 ( MO) . — Lydenburg region , Sukuniland, Barnard 223 ( K, PRE) . — Magaliesberg , c. 3 miles W of Wonderboompoort, Bremerkamp 1280 ( PRU) . — Soutpansberg , near Punch Bowl Hotel, Codd 8339 ( PRE) . — Soutpansberg , near Entebent Forest Station, Codd 8398 ( PRE) . — Rustenburg , below Dunningkamp Dam, Coetzee 869 ( PRE) . — Rustenburg , Collins 10522 ( PRE, J) . — Lebowa , Arabie, about 1 km SE of office complex, Ellery 250 ( PRE) . — Matoks , 24.VIII.1930, Hutchinson & Gillett 4468 ( K) . — Middelburg district , kloofs near Botsebelo Mission station, Little Olifants River, Marloth 11754 ( PRE) . — Thabazimbi , Farm Zwarthoek, N slopes of Aasvoelkop, McMurty 7214 ( PRE) . — Groblersdal district , about 4 miles N of the Lobethal service station, Monnig 46 ( PRE) . — Rustenburg district , Pegler 3008 ( SAM) . — Pietersburg , Pole-Evans 3730(a) ( PRE) . — Burgersfort , 6.VII.1963, Repton 5942 ( K) . — Bankfontein district , Middelburg, Rudatis 226 ( PRE) . — Bandolierkop , 12.XI.1955, Schlieben 7585 ( K) . — Lekgalameetse Nature Reserve , Paris, Stalmans 65 ( PRE) . — Rainhill , c. 5 miles SW of Rustenburg, 19.III.1946, Story 990 ( K, PRE) . — Transvaal , Kruger Nat. Park, Punda Maria, 11.VIII.1953, v.d. Schyff 3151 ( K) . — Brits , Jacksonstuin, Magaliesburg, van Vuuren 312 ( PRE) . — 18 miles E of Pietersburg, road to Tsaneen , 1.IX.1961, v.Vuuren 1266 ( K, PRE) . — Transvaal , Kruger National Park, 19.VIII.1952, Van der Schiff 658 ( K) . — Northern Province , Abel-Erasmus pass, 10 km S of Strydom tunnel, 10.XI.2000, van Wyk 125 ( K) . — C. 50 km N of Pietersburg on the road to Louis Trichardt, van Wyk 5193 ( PRU, PRE) ; van Wyk 5216 ( PRU) . — Mmatlaka , Farm St Etienne, 3.VIII.1985, Venter 10788 ( K) .

Zimbabwe. Matopos National Park , 12.VIII.1980, Best 1416 ( K, MO) . — Near Bulawayo, Eyles 1234 ( SRGH) . — Matopo Hills, Gibbs 3 ( K) . — Fort Victoria, Hall 18 ( NBG) . — Zimbabwe, suburb of Bulawayo, Howe s.n. ( GRA) . — 12 miles N of Lundi Bridge on Fort Victoria-Beit Bridge road, 4.VI.1961, Leach 11103 ( K, MO) . — Matoppos, VIII.1911, Mason s.n. ( K) . — Matobo, Besner Kobila Farm , VII.1953, Miller 1837 ( K, MO, SRGH) . — Matopos , VIII.1951, Plowes 34036 ( K, SRGH) . — Bulawayo district, Khami ruins, Sim 19221 ( PRE) .

REMARKS

Tetradenia brevispicata is confined to scattered localities in the northern provinces of South Africa, eastern Botswana, central Namibia and the Matopo hills in southwestern Zimbabwe. It is known from rocky hills and ridges (granite and quartzite) from about 500-1600 m asl, and has been recorded in flower from June to September.

As its name suggests, T. brevispicata has inflorescences with short rather dense spikes (both male and female). The male flowers are considerably larger (tube ± 1.5 mm long, lower lobe ± 1.4 mm long) than those of T. bainesii with which it is partly sympatric. It is also distinguished by a short fine indument on the vegetative parts, unlike the long woolly indument of T. bainesii . A full description of this species is provided by Codd (1983).

We provisionally include material in this species from the highlands of Central Namibia that was referred by Codd (1983) to T. riparia . While these plants differ slightly from typical T. brevispicata , they cannot be accommodated satisfactorily in any other species. In our view, delimited in this way, the species remains a morphologically and eco-geographically coherent taxon. However, it is possible that the Namibian specimens represent a distinct taxon, and this merits further study.

4. Tetradenia discolor Phillipson , sp. nov. ( Fig. 1 )

Frutex foliis discoloribus, differt a Tetradenia bainesii floribus majoribus et caulibus hispidis.

Moschosma myriostachyum Benth. & Hook. f. Genera Plantarum 2: 1173 (1876), pro parte excl. lectotype. The lectotype is included in T. riparia .

TYPUS. — Malawi. Chambe Plateau, Mlanje Mt., 1900 m, Brass, L.J. 16766 (holo-, K!; iso-, MO!, NY).

PARATYPES. — Democratic Republic of the Congo. N de Kolwezi, 10.IV.1971, Lisowski 15 ( ETH, K) .

Malawi. Michesi hill above Nalingura School, Balaka & Kaunda 1567 ( MAL, P) . — Beside Ngala Mountain on SW side, 23 km SE of Lilongwe, 28.IV.1970, Brummitt 10247 ( K) . — Msese Hill , 8 km N of Mlangeni on Ncheu-Dedza road, 30.IV.1970, Brummitt 10296 ( K) . — Mlanje district, Mlanje Mountain above Fort Lister Forestry Depot on path to Sombani , 8.VI.1970, Brummitt 11367 ( K) . — Side of Mlanje Mountain above Fort Lister Forestry Depot on path to Sombani , 8.VI.1970, Brummitt 11367 ( K) . — Mamule ( Yao ) at Zomba, 19.IX.1929, Burtt Davy 21858 ( K) . — Nyankhava Mountain , Zomba Humbert 17013 ( P) . — 1 mile W of Chiradzulu Mtn , 21.VII.1958 Leach 8124 ( K) . — Zomba Plateau , 13.VIII.1960, Leach 10447 ( K, P) . — Mt Chiradzura, Manganja range, 1.IX.1861, Mellor s.n. ( K) . — 49 miles N of Lilongwe, 7.VI.1938, Pole Evans & Erens 605 ( K, P, PRE) . — Mt. Chiradzulu, 9.III.1905, Whyte s.n. ( K) .

Tanzania. Usafwa, Goetze 1058 ( P) . — Msanzi , on Mbala road SW of Sumbawanga, 2.VI.1980, Hooper & Townsend 1790 ( K) . — Sumbawanga road, roadside growing on big rocks, 16.V.1970, Sanane 1206 ( K) .

Zambia. Northern Province, Kasama district, among rocks, on edge of escarpment with Dissotis sp. (shrub) Diplorhyncus, Vitex sp. , Maprounea near the Forest of Kasama, 11.XI.1952, Angus ( K, MO). — Abercorn, rocks near outflow from Lake Chila, 1949-1951, Bullock 1092 ( K, P). — Lake Ishiku Ndola, 16.IV.1957, Fanshawe 3182 ( K). — Nobola, 7.VII.1954, Fanshawe 1360 ( K). — Shiwa Ngandu, 22.VII.1938, Greenway 5465 ( K). — Solwezi, N. Monument, 24.V.1969, Mutimushi 3501 ( K). — Solwezi district, gorge two miles below Boma on river, 14.VI.1930, Milne-Redhead & Taylor 499 ( K). — Shiwa Ngandu, 1800 m, 4.VI.1956, Robinson 1586 ( K). — Abercorn district, Gorge, Kalambo River, Kalambo Farm, Saisi Valley, 21.V.1952, Richards 1794 ( K). — Rocky hill above Kawimbe, 2.VI.1957, Richards 9982 ( K). — Juuna village edge of dambo, 9.VII.1970, Sanane 1244 ( K, MO). — Serenje district, 57.0 km NW of Chisomo on the Chisomo-Serenje road, c. 30.0 km SE of junction with the Serenje-Mpika road, open miombo woodlands, grasslands, and adjacent cultivated fields with large granitic outcropping of boulders, 8.V.1994, Schmidt, Harder, Nkhoma & Louwiika, B. 1345 ( K, MO). — Mutinondo Wilderness Area, 13.VI.1998, Smith 1728 ( K).

Zimbabwe. No locality, 28.IX.1920, Hislop 103 ( K). — No locality, 28.IX.1920, Hislop Z. 97 ( K, P) .

DESCRIPTION

Aromatic dioecious shrub 1.5-3 m tall, with an indument of stout short (± 0.1 mm), medium-length (± 0.5 mm) and long, fine curly eglandular trichomes and fine short (± 0.1 mm) and medium-length (± 0.5 mm) glandular trichomes. Stems dark brown, with prominent raised scars of fallen leaves, finely hispid with mainly short and some medium-length glandular trichomes, somewhat glabrescent.Leaves elliptic to ovate; blades <80 (130) × 55 (130) mm, margins crenate, teeth rounded <5 × 5 mm, the edges of the teeth revolute,apex usually rounded, base usually rounded, pubescent with erect glandular and eglandular medium-length trichomes above; woolly with densely matted, long white eglandular trichomes and shorter glandular trichomes, and with yellow sessile glands beneath; petioles <1/4 the length of leaf blade, indument like the stems. Inflorescence usually rather compact, branches moderately to densely villose with mainly medium-length eglandular and short glandular trichomes; bracts caducous, c. 1.5 × 2 mm, moderately pubescent on outer surface and with pale yellow sessile glands, spikes dense, usually <2 cm long (male and female), internodes ± 2 (male) or 1 mm (female) long, the axes somewhat or completely hidden by the flowers at anthesis. Flowers shortly (<0.4 mm) pedicellate (male) or subsessile (female). Calyx ± 0.7 × 0.6 mm, moderately to densely hispid to woolly with short white eglandular trichomes and with scattered to many pale yellow sessile glands; fruiting calyx ellipsoidal, ± 1.4 mm long, lobes ± 0.4 mm long. Corolla funnel-shaped, bluish-mauve or white tinged lilac; tube pubescent in throat, glabrous outside, ± 1.5-2.0 mm (male) or 1.0 mm (female) long; lobes spreading widely, glabrous inside, eglandular pubescent outside (except along margins), lower lobe ± 1.1 mm (male) or 0.8 mm (female) long, lateral and upper lobes shorter. Stamens protruding ± 1.8 mm, anthers pale mauve or purple. Style protruding ± 0.5 mm (male) or 2 mm (female), drying purple, lobes ± 0.1 mm (male) or 0.5 mm (female) long. Nutlets brown, ellipsoidal, ± 0.7 × 0.3 mm.

REMARKS

This new species is known from Malawi, Zambia, southwestern Tanzania, and Shaba Province in southeastern Democratic Republic of the Congo, and two collections from unspecified localities in Zimbabwe. It has been found in open miombo woodland on rocky slopes, and at the edge of Dambos, usually among boulders between 1200 and 1800 m asl. It flowers mainly from April to July.

Tetradenia discolor can be recognized by its dense compact male and female inflorescences and its distinctive leaves which are strongly discolorous (the lower surfaces of which are covered in a dense white indument), and which have a rather even, deeply crenate margins, which are usually distinctly revolute. These characteristics are not seen in other specimens within its range. The flowers have a calyx that is moderately to densely hispid to conspicuously woolly with short white eglandular trichomes. One specimen, Burtt Davy 21858, is rather atypical in having leaves with somewhat pointed rather than rounded apices and cordate rather than rounded bases.

Tetradenia discolor could be easily confused with T. bainesii , which has leaves of a similar shape and indument, but the latter has smaller male flowers and a different indument on its vegetative parts (see remarks on T. bainesii ) and occurs further south. At some localities, T. urticifolia can have somewhat discolorous leaves, but the indument is never as dense as in T. discolor , it has other distinctive characteristics, and is not sympatric with T. discolor (see remarks on T. urticifolia ).

One of the two syntypes of Moschosma myriostachya is a plant of T. discolor , while the other syntype is a plant of T. riparia . The selection of the latter as the lectotype is discussed in our remarks on T. riparia .

Figures

FIG. 1. — Tetradenia discolor Phillipson, scanned image of holotype, Brass, L.J. 16766 (K), from Chambe Plateau on Mlanje Mountain at 1900 m in Malawi.