Kosteletzkya rotundalata O. J. Blanch., 2013

Blanchard, Orland J., 2013, A new species of Kosteletzkya (Hibisceae, Malvoideae, Malvaceae) and notes on a second species, both from eastern Democratic Republic of the Congo, Phytotaxa 88 (2), pp. 31-37 : 31-33

Kosteletzkya rotundalata O. J. Blanch. , sp. nov. ( Figs. 1 , 2A )

A K. begoniifolia pedicellis brevioribus, foliis latioribus, fructibus parvioribus, petalis angustioribus et praesertim marginibus valvarum capsularum aspectu laterale rotundatis vice angulosis differt.

Type: — DEMOCRATIC REPUBLIC OF THE CONGO. Prov. Orientale: Saga-Saga (grotte), rég. Mt. Hoyo, elev. 1200 m, 22 July 1955, van Schuytbroeck in de Witte 12579 (holotype, BR!) .

Erect, ascending or scrambling perennial herbs or subshrubs to 2.5 m. Roots fibrous-thickened. Stems +/- retrorsely hispid with yellowish, simple or few-armed stellate hairs mostly 1–2 mm long, underlain by minute multi-armed stellate hairs, and also with a line of short curved hairs extending from node to node, this sometimes obscured. Leaves alternate, petiolate; stipules linear-subulate, 5–6 mm long, setose; petioles 3–8 cm, reduced above, pubescence as in the stems but minute stellate hairs mostly lacking; blades simple, transversely ovate, 6.5–8.5 × 7.5–9.5 cm, base truncate to broadly cordate, margin coarsely and irregularly serrate, apex short-acuminate, the whole shallowly 3-lobed, the lobes arising in the distal 1/3–1/4 of blade, the distal blades smaller, broadly ovate and unlobed, pubescence adaxially of simple or few-armed stellate hairs less dense than on stems, abaxially as in stems but less dense except on nerves. Flowers single in axils of upper leaves, often together with a branch that itself bears flowers in axils of reduced leaves; pedicels 3–8 mm, to 12(–18) mm in fruit, articulated below epicalyx, becoming deflexed distally in fruit, pubescence as in the stems; epicalyx rotate or the segments slightly reflexed, 8–9, linear-filiform, 5–7 mm long, setose, setae ca. 1 mm, simple; calyx broadly campanulate, 9–11 mm long, abaxially with simple or few-armed stellate hairs and minute multi-armed stellate hairs, adaxially sparingly stellate- and glandular-pubescent, less so basally, lobed for about 3/4 its length, lobes triangular, slightly narrowed at base, acute, ciliate; corolla pale pink with a dark red center radiating outward in lines, the petals asymmetrically obovate, 22–30 × 14–20 mm, +/- rounded apically, adaxially glabrous, abaxially stellate- and glandular-pubescent where exposed in bud; staminal column dark red, 15–18 mm, minutely papillose especially toward base, anthers ca. 18–30, confined to the distal 1/2–3/4 of the column, filaments 1.0– 1.4 mm; carpels 5, style-branches deep pink, exserted ca. 3–4 mm, sparingly glandular-pubescent, stigmas capitate, pink. Fruits capsular, depressed-pentagonal, pale brown, 4.0–5.5 × 5–6 mm, capsule-valves ultimately separating from the floral axis and from one another, dorsally transversely rugose, stellate- and glandular-pubescent, marginally ciliate with simple hairs ca. 1 mm long, valve margins in lateral aspect rounded in outline; seeds one per locule, dark brown with fine, pale concentric lines, reniform-obovate, 3.4–3.6 mm long. Chromosome number n = 38.

Paratypes: — DEMOCRATIC REPUBLIC OF THE CONGO. Prov. Orientale : Nizi, 1500 m, 2 February 1953, Liben 444 ( BR!) ; cultivated as 81-81, seed source: DEMOCRATIC REPUBLIC OF THE CONGO. Nizi , 1500 m, 2 February 1953, Liben 444, specimen harvested 27 December 1981, Blanchard 3203 ( FLAS!) ; cultivated as 10-53, seed source: ibid., specimen harvested 19 January 2011, Blanchard 3398 ( FLAS!) .

Distribution and habitat: — Kosteletzkya rotundalata is restricted in its range to northeastern DRC, Province Orientale, Ituri District, where it occurs at elevations from 1200 to 1500 m in rainforest habitats. The two known collection localities are separated by about 70 km ( Fig. 3 ). Both of these records are over half a century old, so it is difficult to know what may be the current status of the species in the wild. The type locality is within the Mt. Hoyo Natural Reserve, an area noted for its numerous caves, of which the "Saga-Saga" of the label data is one. However, in the recent past protection of the reserve from poaching and deforestation is said to have been hindered due to sporadic actions by armed rebels in the area ( Shamavu et al. 2010).

Etymology: —The species epithet refers to the rounded "wings" of the fruit.

Discussion: — Kosteletzkya rotundalata is closely similar and apparently related to the more widely distributed K. begoniifolia ( Ulbrich 1917: 182) Ulbrich (1924: 684) with which it was confused in the herbarium and by Hauman in his treatment of the Malvaceae in Flore du Congo, du Rwanda et du Burundi (1963). It differs from the latter in having smaller capsules that have rounded ( Fig. 2A ) rather than acutely angulate ( Fig. 2B – F ) capsule-valve margins, narrower petals, shorter pedicels and broader leaves.

A recently published chromosome count of n = 38 for this species (as sp. nov. O. J. Blanch. ined.) identifies it as one of the four known tetraploids in the genus ( Blanchard 2012).

Figures

FIGURE 1. Herbarium specimen (a paratype) of a cultivated plant of Kosteletzkya rotundalata O. J. Blanch., sp. nov. Blanchard 3203 (FLAS). Photographed by Kent Perkins.

FIGURE 2. Capsule valves from Kosteletzkya rotundalata (A) and from five different collections of K. begoniifolia (B–F). A. Kosteletzkya rotundalata, DEMOCRATIC REPUBLIC OF THE CONGO. Nizi, Liben 444. B. K. begoniifolia, ETHIOPIA. Sirré, S. Bale, Mooney 8408. C. KENYA. Shores of Lake Naivasha, Blanchard & Blanchard 1352. D. ETHIOPIA. 40 km W of Ambo, de Wilde & de Wilde-Duyfjes 10421. E. TANZANIA. Ngorongoro Crater, Bonnefille & Riollet 73/26. F. KENYA. Seboti, S.E. Elgon, Tweedie 3242. All specimens at FLAS. Scale bar = 5 mm. Photographed by Jane Blanchard.

FIGURE 3. Map of a part of eastern and northern Africa showing the known distributions of Kosteletzkya rotundalata (green dots, light gray in print version) and K. borkouana (red dots, dark gray in print version). Prepared by Kurt Neubig.