Barleria brownii S.Moore

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/154071578/154074739

Conservation

LC - least concern

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

Uganda, Entebbe, fl. Aug. 1905, Brown 313 (lectotype BM! [BM000931100], selected here; isolectotypes K! [K000394444, K000394445]).

Morphology General Habit

Straggling or scandent perennial herb or shrub, 40 – 600 cm tall; young stems with short retrorse hairs in two opposite lines, nodes and uppermost internodes sparsely yellow-strigose, soon glabrescent

Morphology Leaves

Leaves on petiole 10 – 37 mm long; blade ovate to oblong-elliptic, 6 – 13 × 3 – 6.5 cm (l:w ratio 1.7 – 2.8:1), base cuneate, shortly attenuate or rounded, margin entire, apex acuminate or attenuate, glabrous except for occasional appressed hairs on main veins; lateral veins 4 – 6 pairs

Morphology Reproductive morphology Inflorescences

Inflorescences of 2 – 9-flowered, unilateral or partially dichasial cymes arranged in a paniculate or spiciform terminal thyrse 2 – 12 cm long; bracts broadly ovate to somewhat obovate, 6 – 25 × 3.5 – 23 mm; bracteoles variable, linear, oblanceolate, obovate or elliptic, 2 – 18 × 0.3 – 7 mm, margin entire, surface appressed-pubescent or sparsely so

Morphology Reproductive morphology Flowers Calyx

Calyx variable [see note], in our region anterior lobe elliptic to ovate-orbicular, 10.5 – 19.5 × 8 – 17 mm, base obtuse to rounded, margin entire, apex obtuse to rounded or shallowly emarginate, surface appressed-pubescent or sparsely so, with or without few long glandular hairs particularly towards apex; posterior lobe 11 – 24 × 8 – 19 mm, margin often involute, apex obtuse or slightly attenuate; lateral lobes 5 – 7.5 mm long

Morphology Reproductive morphology Flowers Corolla

Corolla 30 – 50 mm long, white, pinkish-white or blue, throat often tinged pink or purple; glandular-pilose and with fewer eglandular hairs externally; tube 13.5 – 21 mm long, campanulate above attachment point of stamens; limb in “4+1” configuration, abaxial lobe offset by 2.5 – 6.5 mm, obovate or elliptic, 16 – 27 × 11.5 – 15 mm, apex rounded; lateral lobes obovate-elliptic to oblong-elliptic, 14.5 – 26 × 7.5 – 12.5 mm, apices rounded or obtuse; adaxial lobes as lateral pair but 4.5 – 8 mm wide

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens inserted 5.5 – 9 mm from base of corolla tube, long exserted; filaments 35 – 65 mm long; anthers 2.5 – 4 mm long; lateral staminodes 1.5 – 9.5 mm long, with minute stalked glands and occasional hairs towards base or throughout, antherodes well developed, 1.2 – 2 mm long

Morphology Reproductive morphology Flowers Gynoecium Pistil

Pistil glabrous; stigma long exserted, clavate, 0.4 – 0.9 mm long

Morphology Reproductive morphology Fruits

Capsule 2-seeded, 12.5 – 14.5 mm long, glabrous; seeds ± 6 × 5 mm.

Distribution

Angola (Cabinda and Lunda Norte Provinces.); widespread in the Guineo-Congolian forests of Ghana, Nigeria, Cameroon, Central African Republic, Equatorial Guinea, Gabon, Congo (Brazzaville), D. R. Congo, South Sudan, Ethiopia, Uganda and Tanzania.

Ecology

In Angola, Barleria brownii has been recorded in riverine and lowland forest, often in clearings, margins or areas of secondary regrowth; 50 – 700 m elevation. It is a species of the Guineo-Congolian Regional Centre of Endemism (White 1983).

Conservation

This species is widespread in the Guineo-Congolian forests with an EOO of over 3.9 million km2 and can be locally common including in disturbed habitat; it was assessed as of Least Concern (LC) by Darbyshire (2010b). In Angola, it is at the southwestern edge of its range and is restricted to the Maiombe forests of Cabinda and the forests of the north-flowing rivers (Congo tributaries) of Lunda Norte. It was recorded as very frequent by Monteiro & Murta at Buco Zau in Cabinda in 1960. However, forest extent has declined in this region over recent decades, with extensive mining activity being clearly visible on Google Earth imagery. Much of the riverine forest around Dundo in Lunda Norte has also been lost due to extensive alluvial diamond mining along the Luachimo River and its tributaries and expansion of Dundo town (Huntley 2011; Cheek et al. 2015). Therefore, this species is likely to be nationally threatened in Angola under IUCN criterion B.

Note

The Angolan specimens seen have broadly elliptic to ovate-orbicular outer calyx lobes which match the form described from Nigeria as Barleria talbotii S. Moore (Rendle et al. 1913). However, as noted in Darbyshire (2010b), intermediates between this form and the narrower oblong-elliptic outer calyx lobes of typical B. brownii are recorded in West and Central Africa. As there is no clear geographic trend, talbotii would at most warrant varietal status.

Acanthaceae, H. Heine. Flora of West Tropical Africa 2. 1963

Morphology General Habit

A straggling shrub with smooth branches

Morphology Reproductive morphology Flowers

Blue flowers about 2 in. long.