Astiella latifolia Groeninckx, 2017

Groeninckx, Inge, Janssens, Steven, Smets, Erik & Verstraete, Brecht, 2017, Description of 11 new Astiella (Spermacoceae, Rubiaceae) species endemic to Madagascar, European Journal of Taxonomy 312, pp. 1-40 : 25-27

Astiella latifolia Groeninckx sp. nov.

http://www.ipni.org/urn:lsid:ipni.org:names:77161722-1

Figs 2H , 5 L–M, 11B, 12

Diagnosis

Astiella latifolia sp. nov. resembles A. desseinii sp. nov. in having sessile flowers, elongated placentas, ovoid capsules, identical seed and pollen morphology, but differs in the creeping habit (vs erect), the ovate to broadly ovate leaves with prominent secondary veins (vs linear leaves with secondary veins invisible), and the funnel-shaped corolla tubes with the stamens always included (vs cylindrical corolla tubes with the stamens exserted beyond the corolla throat in brevistylous flowers).

Etymology

The species name is derived from the Latin adjective ‘ latus ’ (= broad, wide) and noun ’ folium ’ (= leaf), referring to the ovate or broadly ovate leaves. It also refers to the illegitimate name Oldenlandia latifolia Baker.

Type

MADAGASCAR: Fianarantsoa, PK 365 on RN 2 from Antananarivo to Fianarantsoa, dense low grassy vegetation alongside road and Eucalyptus forest, 1213 m, 29 Jan. 2007, De Block et al. 2255 (holo-: BR; iso-: BR, MO, P, TAN).

Additional material examined

MADAGASCAR: Antananarivo province, Vakinankaratra region, Antsirabe I district, Antsirabe, vieux murs, 1500 m, Apr. 1919, Perrier de la Bâthie 12577 ( P). Betafo district, Environs de Tritriva, près Antsirabe, cratères basaltiques, endroits humides, 1700 m, May 1912, Perrier de la Bâthie 3936 ( P). Diana region, Ambanja district, Marovato,Ambanja, 13 Mar.1954, Sajy 6309-RN ( P, TAN). Fianarantsoa province, Amoron’i Mania region, Ambatofinandrahana district, Environs d’Ambatofinandrahana, sables quartzeux, 1600–1800 m, 23 Feb. 1938, Decary 19278 ( P). Haute Matsiatra region, Ambalavao district, RN 5, Sendrisoa, Ambalavao, 19 Mar. 1952, [Razafindzakolo] 3984-RN ( P). Ambohimahasoa district, Süd-Betsiléo, Wald von Ankafina, Mar. 1881, Hildebrandt 3941 (K, P). Fianarantsoa district, Fianarantsoa, rocailles, Apr. 1912, Perrier de la Bâthie 3584 ( P). Horombe region, Ivohibe district, Andringitra, in manioc field, 1542 m, 28 Jan. 2006, De Block, Tosh & Rakotonasolo 1920 ( BR, MO, P, TAN). Mahajanga province, Boeny region, Ambato Boeni district, road from Ankarafantsika to Ambato- Boeni, ca 5 km after turn-off to Ambato-Boeni, close to Tsararivotra, hill on left side of the road when coming from Ankarafantsika, 88 m, 21 Mar. 2010, De Block, Groeninckx & Rakotonasolo 2361 ( BR, K, MO, P, TAN); Ankarafantsika, Jardin Botanique B, 144 m, 21 Mar. 2010, De Block, Groeninckx & Rakotonasolo 2364 ( BR, K, TAN); Anjiafitatra, près de Mont Tsitondroina (Boeny), sables ombragées, Mar. 1901, Perrier de la Bâthie 1254 ( P); Ankarafantsika, sables très sec, Jan. 1902, Perrier de la Bâthie 3686 ( P). Mahajanga I district, Ambodiroka, Betsiboka, Jan. 1902, Perrier de la Bâthie 4035 ( P). Marovoay district, Ampijoroa, Jardin Botanique, section A, on sandy path in forest, temporarily humid, 10 Feb. 1999, De Block, Luckow & Rakotonasolo 780 ( BR, MO, TAN). Sofia region, Boriziny district, edge of RN 6, ca 17 km N of Port Bergé, left side of the road coming from Port Bergé, seasonally dry semi-deciduous forest, on white sand, 17 Mar. 2010, Groeninckx, De Block & Rakotonasolo 261 ( BR, K, MO, P, TAN); edge of RN 6, ca 17 km N of Port Bergé, left side of the road coming from Port Bergé, seasonally dry semi-deciduous forest, on white sand, 17 Mar. 2010, Groeninckx, De Block & Rakotonasolo 262, 267 ( BR, K, MO, TAN). Toliara province,Androy region,Ambovombe district, 43 km from Ambovombe on road from A1 to Betroka, grass along road, 187 m, 8 Feb. 2007, De Block et al. 2334 ( BR, TAN). Anosy region, Taolanaro district, Fort-Dauphin, Scott Elliot 3059 (K, P). Locality unknown, s. loc., s.d., Baron 307 (K); s. loc., s.d., Baron 5214 ( P); s. loc., s.d., Blackburn s.n. (K); s. loc., s.d., Boivin 115 ( P).

Description

Annual herb, creeping, less than 10 cm tall, rooting at the nodes; stems quadrangular in cross section, only sparsely branching, with short (ca 0.2 mm) and longer (ca 0.7 mm) white trichomes on the adaxial side, glabrous or with short white trichomes on the abaxial side, light brown, purplish brown or reddish brown. Stipule base 1–1.5 mm long, beset with a few trichomes (up to 1 mm long); fimbriae 2–4, 0.8–2.7 mm long, beset with trichomes (up to 1 mm long), colleter-tipped. Leaves petiolate, rarely sessile, anisophyllous; petioles 0.5–6 mm long; blades elliptic, ovate or broadly ovate, large leaves 5–20(– 30) × 4–12 mm, small leaves 4–9.5 × 3–8.8 mm, glabrous or sparsely covered with short (ca 0.6 mm) appressed trichomes above particularly at the base (especially on younger leaves), glabrous below except for midvein and secondary veins that are covered with very short (ca 0.2 mm) erect trichomes, darker green above, paler green below; base attenuate; apex acute; margin scabrate towards the apex, ciliate at the base; midvein prominent below; secondary veins 3–4 on each side of the midvein, somewhat prominent below; intersecondaries invisible. Inflorescences terminal 3- to several-flowered and pseudo-axillary 1- or 2-flowered; peduncle absent. Flowers sessile, heterostylous. Calyx green to purplish; tube reduced; lobes 4, narrowly triangular, 1.5–2.5 × 0.2–0.5 mm, margin ciliate with trichomes up to 1 mm long. Corolla white, pale pink or pale purple; tube funnel-shaped, 3.5–5.4 mm long, 2–2.8 mm wide at the throat and 0.5–1.1 mm wide at the base in brevistylous flowers, 6.8–8.5 mm long, 3.5–4.8 mm wide at the throat and 0.8–1.2 mm wide at the base in longistylous flowers, glabrous or with a few trichomes outside, covered with long spreading trichomes (up to 1 mm long) inside at the base and sometimes at the throat; lobes 4, ovate to broadly ovate, 1.7–2.5 × 1.5–2 mm in brevistylous flowers, 3.2–3.8 × 2.8–3.5 mm in longistylous flowers, glabrous or covered with a few trichomes outside, sparsely covered with long spreading trichomes (up to 1 mm long) inside. Stamens inserted at 3.5–4 mm height in the corolla tube in brevistylous flowers, inserted at 1.5–3 mm height in the corolla tube in longistylous flowers, always included. Anthers broadly obovoid, 0.4–0.6 mm long, white; filaments dorsifixed, 0.3–0.7 mm long. Pollen tricolporate, prolate spheroidal, sometimes oblate spheroidal or subprolate in brevistylous flowers, subprolate in longistylous flowers; E 22–26 μm in brevistylous flowers, 22–25 μm in longistylous flowers; P 24–26 μm in brevistylous flowers, 26– 28.5 μm in longistylous flowers; ectocolpi long; endocolpi long; tectum bireticulate; suprareticulum microreticulate to reticulate; infrareticulum perforate to microreticulate with granules. Ovary 2-locular, ovoid, 1.3–1.4 × 1.2–1.3 mm, sparsely covered with trichomes; placenta attached near the middle of the septum, stalked, elongated, bearing 5–10 ovules per locule. Style 3.3–4.8 mm long in brevistylous flowers, 6–8 mm long in longistylous flowers, always included, glabrous, white; stigma bilobed, lobes 0.5–0.8 mm long in brevistylous flowers, 1.5–2 mm long in longistylous flowers, hirtellous. Capsules ovoid, 3–4.5 × 2–3.5 mm, with beak 0.8–1.7 mm long, crowned with the persistent calyx lobes, glabrous or covered with a few trichomes, green with brown beak, dehiscence loculicidal. Seeds 5–10 per locule, elliptic in outline, ventral groove absent, 0.6–0.8 × 0.5–0.6 × 0.4–0.6 mm, black; seed coat surface reticulate, testa cells with undulating radial walls, microsculpturing granulate.

Distribution

NW to SE Madagascar: Antananarivo province, Vakinankaratra region, Antsirabe I and Betafo districts; Antsiranana province, Diana region, Ambanja district; Fianarantsoa province, Amoron’i Mania region, Ambatofinandrahana district; Fianarantsoa province, Haute Matsiatra region, Ambalavao, Ambohimahasoa, and Fianarantsoa districts; Fianarantsoa province, Horombe region, Ivohibe district; Mahajanga province, Boeny region, Ambato Boeni, Mahajanga I, and Marovoay districts; Mahajanga province, Sofia region, Boriziny district; Toliara province, Androy region, Ambovombe district; Toliara province, Anosy region, Taolanaro district.

Habitat

Western dry forest and humid forest; often disturbed vegetations (i.e. degraded dry forest, grass along roads, sandy paths in forests, manioc fields and walls); sand; at 88–1800 m elevation.

Vernacular name

Masiramboalavo.

Conservation status

The species is known from 23 collections, of which four without locality. The extent of occurrence equals 195,897.347 km 2 and the area of occupancy equals 72 km 2. Astiella latifolia sp. nov. has frequently been collected from disturbed areas. No real threats could be identified and the species does therefore not qualify for an IUCN red list threatened category (LC).

Figures

Fig. 2. Distribution maps. A. Astiella antongilensis Groeninckx sp. nov. B. A. antsalovansis Groeninckx sp. nov. C. A. confusa Groeninckx sp. nov. D. A. deblockiae Groeninckx sp. nov. E. A. delicatula Jovet. F. A. desseinii Groeninckx sp. nov. G. A. homolleae Groeninckx sp. nov. H. A. latifolia Groeninckx sp. nov. I. A. longifimbria Groeninckx sp. nov. J. A. perrieri Groeninckx sp. nov. K. A. pulla Groeninckx sp. nov. L. A. tsaratanensis Groeninckx sp. nov.

Fig. 5. Scanning electron microscopy micrographs of seeds and a detail of their surface. A–B. Astiella antsalovansisGroeninckx sp. nov.C–D.A. deblockiaeGroeninckx sp. nov.E–F.A. desseiniiGroeninckx sp. nov. G–I. A. delicatula Jovet. J–K. A. homolleae Groeninckx sp. nov. L–M. A. latifolia Groeninckx sp. nov. N–O. A. perrieri Groeninckx sp. nov. P–R. A. tsaratanensis Groeninckx sp. nov. Scale bars for A, C, E, J, L, N = 100 µm; B, I = 50 µm; D = 10 µm; F, K, M, O, R = 20 µm; G, H, P, Q = 200 µm.