Barleria ameliae A.Meeuse

Darbyshire, I., Tripp, E.A. & Chase, F.M. (2019). A taxonomic revision of Acanthaceae tribe Barlerieae in Angola and Namibia. Part 1. Kew Bulletin 74: 5. https://doi.org/10.1007/s12225-018-9791-0

Type

Namibia, Caprivi Strip, Mpilila Island, fl. 15 Jan. 1959, Killick & Leistner 3391 (holotype PRE; isotypes K! [K000394535, K000394536], L, M! [M0109645], SRGH, WIND).

Morphology General Habit

Perennial herb or subshrub, erect or decumbent, 15 – 120 cm tall, often rooting at lower nodes; stems 4-angular, glabrous or minutely puberulous, woody portion of stems with pale grey or sandy-coloured bark

Morphology General Spines

Axillary spines present but inconspicuous, pale brown or whitish, 4-rayed, stalk to 1 mm long, longest ray 2 – 7 mm long

Morphology Leaves

Leaves on petiole to 13 mm long, blade elliptic or elliptic-obovate, 4.8 – 10.5 × 1.6 – 4.7 cm (l:w ratio 2 – 3.5: 1), base cuneate-attenuate, long-decurrent, margin entire, apex acute or attenuate, tip mucronulate, margin, midrib and veins beneath strigose, later glabrescent

Morphology Reproductive morphology Inflorescences

Inflorescences axillary or a ± weakly defined terminal spike, 2.5 – 22 cm long, lax or rarely contracted, each cymule 1- or 3-flowered, sessile; bracts ± spreading, lower pairs foliaceous, gradually reducing distally where oblanceolate, 11 – 38 (– 48) × 2.5 – 15 mm, apex acute or shortly attenuate, mucronate, hairs as leaves beneath or more widespread; bracteoles white-green, lanceolate-spinose, 2.5 – 10.5 × 0.8 – 1.2 mm, margin entire

Morphology Reproductive morphology Flowers Calyx

Calyx green, often paler towards base or pale green throughout; anterior and posterior lobes subequal, ovate or lanceolate, anterior lobe 10.5 – 14 (– 16.5) × 3 – 5.5 mm, posterior lobe 11 – 17 (– 20) mm long, margin entire, apex acute or attenuate, spinose, anterior lobe sometimes notched, external surface strigose, rarely also with few short glandular hairs towards apex, venation parallel, prominent in fruit; lateral lobes linear-lanceolate, 10 – 14 mm long

Morphology Reproductive morphology Flowers Corolla

Corolla yellow, orange or apricot, 27 – 40 mm long, pubescent externally with mixed glandular and eglandular hairs; tube cylindrical, 10 – 18 mm long; limb in “4+1” configuration; abaxial lobe offset from remaining lobes by 4.5 – 8 mm, (elliptic-) obovate, 9 – 14 × 5 – 7.5 mm, apex rounded or obtuse; lateral and adaxial lobes subequal, elliptic, 11 – 16 × 6.5 – 8.5 mm or adaxial lobes narrower, minimum 4.5 mm wide, apices obtuse or acute

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens inserted 8 – 11 mm from base of corolla tube; filaments 11.5 – 21 mm long, pubescent in proximal two thirds; anthers 2.5 – 4 mm long; lateral staminodes 1.3 – 2 mm long, pubescent, antherodes ± 1 mm long

Morphology Reproductive morphology Flowers Gynoecium Pistil

Pistil glabrous or ovary minutely hairy; stigma linear, 0.7 – 1.1 mm long

Morphology Reproductive morphology Fruits

Capsule 13 – 16 mm long, glabrous or sparsely and minutely hairy; seeds 7 – 8 × 4.5 – 6 mm.

Distribution

Namibia (Zambezi Region); Mozambique, Malawi, Zambia, Zimbabwe, South Africa (Mpumalanga Province), eSwatini.

Ecology

In Namibia, Barleria ameliae has been recorded from poorly drained scrub on gravelly clay soils; c. 900 – 950 m elevation. Elsewhere within its range it is widespread in drier woodland types within the Zambesian Regional Centre of Endemism (White 1983), most notably in Colophospermum mopane and Acacia woodland on sandy soils, but also recorded from dry open riverine forest and thicket, and from seasonally inundated Acacia wooded-grassland.

Conservation

This species is highly restricted in Namibia, being known only from Mpalila Island in Zambezi Region (formerly the Caprivi Strip) where it was recorded as rare by P. du Preez. Much of the woodland habitat in the Zambezi Region has been degraded and so this species is likely to be nationally threatened under IUCN criterion B. However, on a global scale this species is widespread and fairly common in drier Zambesian woodlands and, although the complete EOO has not been calculated, it is known to be in excess of 800,000 km2. Therefore, it is not considered to be globally threatened and has been assessed as of Least Concern — LC (Darbyshire 2015).

Note

Darbyshire (2015) recorded this species as being restricted to the Flora Zambesiaca region, but a recent loan of southern African specimens of Barleria sect. Prionitis from PRE to K has revealed that it also occurs in eSwatini and eastern Mpumalanga.

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: confident

Flora Zambesiaca Acanthaceae (part 2) by Iain Darbyshire, Kaj Vollesen and Ensermu Kelbessa

Morphology General Habit

Perennial herb or subshrub 15–120 cm tall, erect or decumbent, often rooting at lower nodes; stems glabrous or minutely puberulous; woody stems with pale grey or sandy bark.

Morphology General Spines

Axillary spines small, 4-rayed, stalk to 1 mm long, longest ray 2–7 mm long.

Morphology Leaves

Leaves elliptic(-obovate), 4.8–10.5 × 1.6–4.7 cm, base cuneate-attenuate, long-decurrent, apex acute or attenuate, mucronulate, margin, midrib and veins strigose beneath, glabrescent; petiole to 13 mm.

Morphology Reproductive morphology Inflorescences

Inflorescence axillary or a ± weakly defined terminal spike, 2.5–22 cm long, lax or rarely congested, each cymule 1- or 3-flowered, sessile; bracts ± spreading, lower pairs foliaceous, reducing upwards where oblanceolate, 11–38(48) × 2.5–15 mm, apex acute or shortly attenuate, mucronate, hairs as leaves beneath or more widespread; bracteoles white-green, lanceolate-spinose, 2.5–10.5 × 0.8–1.2 mm.

Morphology Reproductive morphology Flowers Calyx

Outer calyx lobes subequal, ovate or lanceolate, anterior lobe 10.5–14(16.5) × 3–5.5 mm, posterior lobe 11–17(20) mm long, apex acute or attenuate, spinose, anterior lobe sometimes notched, surface strigose, rarely with a few minute glandular hairs towards apex, venation parallel, prominent in fruit; lateral lobes 10–14 mm long.

Morphology Reproductive morphology Flowers Corolla

Corolla 27–40 mm long, yellow, orange or apricot, pubescent externally; tube 10–18 mm long; limb in 4+1 arrangement; abaxial lobe 9–14 × 5–7.5 mm, offset by 4.5–8 mm; lateral and adaxial lobes subequal, 11–16 × 6.5–8.5 mm or adaxial lobes narrower, minimum 4.5 mm wide.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens with filaments 11.5–21 mm long, pubescent in proximal two-thirds; anthers 2.5–4 mm; lateral staminodes 1.3–2 mm, pubescent, antherodes c.1 mm.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary glabrous or minutely hairy; style glabrous; stigma linear, 0.7–1.1 mm long.

Morphology Reproductive morphology Fruits

Capsule 13–16 mm long, glabrous or sparsely and minutely hairy.

Morphology Reproductive morphology Seeds

Seeds 7–8 × 4.5–6 mm.

Distribution

Not known elsewhere.

Ecology

Mainly in mopane and Acacia woodland on sandy soils, and dry open riverine forest and thicket; 100–1100 m.

Conservation

Conservation notes: Widespread but patchily distributed, can be locally common or abundant in dry woodland; Least Concern.