Schizolaena charlotteae Lowry & G. E. Schatz, 2014

Lowry II, Porter P., Nusbaumer, Louis, Randrianasolo, Armand, Schatz, George E. & Hong-Wa, Cynthia, 2014, Endemic Families of Madagascar. XIII. New, restricted range species of Eremolaena Baill. and Schizolaena Thouars (Sarcolaenaceae), Candollea 69 (2), pp. 183-193 : 188-190

Schizolaena charlotteae Lowry & G. E. Schatz , spec. nova ( Fig. 2E , 4 ).

Typus: MADAGASCAR. Prov. Toliara: Région Anosy, Bemangidy , Commune Iabokoho , Fokontany Antsotso , Ivohibe forest , 24°34’10’’S 47°12’37’’E, 41 m, 24.V.2006, fr., Antilahimena 4876 (holo-: MO-6564308 !; iso-: G!, K!, P [P00722627]!, TAN!, WAG!).

Schizolaena charlotteae Lowry & G. E. Schatz differs from its most similar congener, S. milleri Lowry & al., by its sparse grayish stellate indument obscuring the dark outer surface of the sepals beneath (vs. dense whitish stellate indument not obscuring the sepal surface), large petals 10- 14 mm long that are bright pinkish red grading to yellow toward the margins (vs. 7-8 mm long and white), 90 to 100 stamens (vs. ca. 265), and an involucre in fruit with processes that are 10-16 mm long and 1 mm wide below the apex (vs. 3-9 mm long and 0.2-0.5 mm wide).

Shrubs to trees 2-15 m tall. Twigs glabrous or sparsely hispidulose, with small, elongate lenticels. Leaves elliptic to slightly ovate or obovate, chocolate brown above (in dry material), lighter and more orangish below, subcoriaceous, (3-)4- 7.5 × (1.2-) 1.5-3 cm, glabrous on both surfaces, base broadly cuneate to rounded, margin entire, minutely thickened, slightly revolute, apex acute to nearly rounded, sometimes slightly retuse, venation brochidodromous, with 6 to 9 pairs of alternate to subopposite, weakly raised secondary veins joined by rounded arches, midrib plane above, raised below; petiole 6- 9 mm long, glabrous or with scattered stellate indumentum; stipules narrowly ovate to ovate, membranous, with nearly obscure parallel venation, 10-12 × 5-7 mm, base rounded, apex acute, caducous, leaving a small scar. Inflorescence comprising 1 or 2 (rarely 3) unbranched axes, each with a pair of bracts borne near the middle and bearing 1 or 2 terminal flowers, axis ca. 10 mm in bud, expanding to 20-22 mm at anthesis, moderately to densely papillose stellate-strigose, bracts broadly elliptic to nearly circular, 4 × 3-4 mm, apex rounded, minutely stellate on abaxial surface, pubescent on adaxial surface, caducous, ultimate axes below the involucre 6-10 mm long, moderately papillose stellate, involucre in flower broadly cupuliform, with numerous cylindrical to narrowly triangular teeth, moderately to densely papillose stellate on both surfaces, containing 1 or 2 sessile flowers; sepals 3, imbricate, broadly ovate, adaxially concave, 9-10 × 6 mm at anthesis, with short stellate-papillose indumentum on the exposed part of the abaxial surface, the portion hidden by the overlapping adjacent sepal with both papillose stellate and short lanate indumentum, margins entire, the hidden portion tinged deep pinkishred, apex rounded to acute; petals 5, obovate, bright pinkish red, yellow toward the margins, slightly succulent in fresh material, chartaceous when dry, 10-14 × 6-8 mm, with dense, appressed sericeous indument in the central portion of the abaxial surface, glabrous toward the entire margins, glabrous on the adaxial surface, apex rounded to broadly acute; stamens ca. 90-100, filaments slender, ca. 4 mm long, glabrous, anthers elliptic to nearly circular, 0.8 mm long, introrse, dehiscent through longitudinal slits; ovary broadly conical, densely white woolly tomentose, 3-locular; style cylindrical, erect, ca. 9 mm long, stigma terminal, minutely 3-lobed, glabrous. Fruit subglobose, ca. 15 mm in diam., with dense stellate indumentum, most trichomes with the central branch much longer than the others, capsule dehiscent by 3 longitudinal sutures, exocarp cartilaginous, rugose, dry sepals and filaments persistent; involucre expanded, broadly cupulate, fleshy and sticky, green in nearly mature fresh material, ca. 25 × 20 mm, sparsely stellate pubescent to glabrous on both surfaces, with 5 broadly ovate, nearly equal lobes divided ca. 1/2 of the way to the base, each lobe with 7 to 10 narrowly triangular to lanceolate or cylindrical, occasionally bifid processes, each 7-16 mm long, ca. 1 mm wide just below the apex; seeds 1 per locule.

Distribution and ecology. – Schizolaena charlotteae is known only from lowland humid forest at Bemangidy- Ivohibe, situated just a few km to the west of the village of Antsotso in the Tsitongambarika New Protected Area, which encompasses much of the Vohimena range to the north of Tolagnaro ( Fig. 3 ).

Conservation status. – The sole forest (Bemangidy-Ivohibe) from which Schizolaena charlotteae is currently known has temporary protection status as part of the larger Tsitongambarika New Protected Area. However, until permanent protection has been established, the forest is still potentially subject to local disturbance and illicit exploitation, especially along its eastern edge where S. charlotteae has been collected. Therefore, with a very restricted AOO of ca. 20 km 2 and only a single location, coupled with the possibility for rapid decline due to the effects of human activities if protection of the Bemangidy-Ivohibe forest is not maintained, S. charlotteae can be assigned a risk of extinction of “Vulnerable” [VU D2] following IUCN Red List Categories and Criteria ( IUCN, 2012).

Notes. – Schizolaena charlotteae is part of a morphologically coherent group of species that also includes S. laurina Baill. , S. milleri Lowry & al. and S. rosea Thouars , characterized by several features including: glabrous petioles and young branches; dense, straight, appressed indumentum on the abaxial surface of the petals; ovate and usually persistent stipules and inflorescence bracts; and an involucre in fruit that is broadly to narrowly cupuliform or funnelform. Indeed, one of the collections of our new species, Service Forestier 28662, was originally assigned by LOWRY & al. (1999) to S. milleri , known otherwise only from littoral forest on white sand and low elevation humid forest on laterite, from near the village of Ambavala (north of Sambava) extending south to Foulpointe, fully 800 km to the north of the only known locality of S. charlotteae .

Using the key to species of Schizolaena provided by LOWRY & al. (1999), material of this new species would be identified as S. milleri . However, it differs in several features of the flower and fruiting involucre, as indicated below in Table 1 . Specimens of Service Forestier 28662 at P were originally annotated as ‘ S. delphinensis ’ by J.-F. Leroy, but the name was never validly published.

The Bemangidy-Ivohibe forest has been the focus of intensive botanical inventory conducted over the last decade by teams from the Missouri Botanical Garden and the Rio Tinto-QMM mining company in order to assess its suitability as a conservation offset site ( BIRDLIFE INTERNATIONAL, 2011; TEMPLE & al. 2012). Dozens of new taxa have been documented from Bemangidy-Ivohibe, some of which have already been described, including new genera of Sapotaceae , Bemangidia L. Gaut. AUTIER & al., 2013) and Asteraceae , Lowryanthus Pruski RUSKI, 2014) and new species in several families such as Gnidia razakamalalana Z. S. Rogers ( Thymelaeaceae ; ROGERS, 2006), Ivodea anosiensis Rabarim. & al. and I. macrocarpa Rabarim. & al. ( Rutaceae ; RABARIMANARIVO & al., in press), and Micronychia bemangidiensis Randrian. & Lowry ( Anacardiaceae ; RANDRIANASOLO & LOWRY, 2009).

Etymology. – This species is named in honor of our friend and colleague Professor Charlotte Rajeriarson, recently retired from the Université d’Antananarivo, who has played a key role in training an entire generation of Malagasy botanists, and who served as the first President of the IUCN Madagascar Plant Specialist Group, helping to ensure the successful establishment of this important national initiative.

Paratypes. – MADAGASCAR. Prov. Toliara: Région Anosy, Tsitongambarika , Commune Iabokoho , Fokontany Antsotso , forêt dense humide d’Ivohibe , 24°34’S 47°11’E, 5.IV.2008, fl., Ramison & al. 581 ( G, MO-6564309 , P [ P00722628 ], TEF); ibid. loc., 24°34’04’’S 47°12’37’’E, 90 m, 9.II.2006, fl., Randriatafika & al. 653 ( MO, P [ P00722633 ], TEF); Forêt de Bemangidy , entre les fleuves Vatomena et Manambato, au N de Ft. Dauphin, [24°34’S 47°12’E], 14.XII. 1968, fl., Service Forestier 28662 ( MO-5189144 , P [ P00490165 , P00490166 ]).

Figures

Fig. 2. – Photographs of Eremolaena darainensis Nusb. & Lowry (A-D) and Schizolaena charlotteae Lowry & G. E. Schatz (E). A. Flower, from above (petals fallen); B. Detail of midvein on abaxial leaf surface showing long white stellate trichomes near the margin and small stellate-strigose indument on nerves; C. Flower, from side (2 petals remaining); D. Detail of abaxial surface of a sepal, with stellate-strigose indument on the overlapping part less dense on the left side than on the right side; E. Flower and buds with young involucres. [A-D: Nusbaumer & Ranirison LN 1420; E. RandriataFika & al. 653] [Photos: A-D: L. Nusbaumer; E: P. Lowry].

Fig. 4. – Schizolaena charlotteae Lowry & G. E. Schatz. A. Branch with fruiting involucre; B. Flower (from above); C. Involucre surrounding mature fruit; D. Detail of leaf; [A-B, D: Antilahimena 4786; C: RandriataFika & al. 653] [Drawing: R. L. Andriamiarisoa]

Fig. 3. – Geographic distribution of Eremolaena darainensis Nusb. & Lowry (stars), Schizolaena charlotteae Lowry & G. E. Schatz (circles) and Schizolaena parvipetala Randrian. & Hong-Wa (squares), mapped on the bioclimatic zones of Madagascar (after CORNET, 1974; see SCHATZ, 2000).