Astiella confusa 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 : 11-13

publication ID	https://doi.org/ 10.5852/ejt.2017.312
DOI	https://doi.org/10.5281/zenodo.3846894
persistent identifier	https://treatment.plazi.org/id/039E3C56-5A27-FF8E-9D7A-0183E18C095F
treatment provided by	Carolina
scientific name	Astiella confusa Groeninckx
status	sp. nov.

Treatment

Astiella confusa Groeninckx View in CoL sp. nov.

http://www.ipni.org/urn:lsid:ipni.org:names:77161715-1

Figs 2C View Fig , 6 View Fig

Diagnosis

Astiella confusa sp. nov. resembles A. tsaratanensis sp. nov. in having few ovules per locule, broadly depressed obovoid capsules crowned with the persistent calyx lobes, and black seeds that are elliptic in outline and have a ventral groove, but differs in its erect habit (vs scrambling or prostrate), the much shorter corolla tube (1.5–1.7 mm vs 4.8–9.5 mm long), the tricolporate pollen (vs 7- to 8-colporate), and the reticulate seed coat surface with favulariate microsculpturing (vs an alveolate seed surface with rugulose microsculpturing).

Etymology

The specific epithet is the feminine participle of the Latin verb ‘ confundo ’, meaning ‘to confuse’, and refers to the fact that this species has been confused with A. delicatula .

Type

MADAGASCAR: Toliara province, Anosy region, Taolanaro district. Bassin de la Manampanihy (sud est), mont Vohimavo au nord d’Ampasimena, rochers du sommet, forêt ombrophile sur argiles latériques et granite, 830 m, 27–28 Mar. 1947, Humbert 20713 (holo-: BR; iso-: MO).

Description

Herb, up to 60 cm tall; stems quadrangular in cross section, glabrous. Stipule base 0.5–1.5 mm long, pubescent; fimbriae usually bifid, 0.4–1.2 mm long, colleter-tipped. Leaves sessile; blades narrowly elliptic, 2.5–20 × 0.5–4.2mm, glabrous or scabrate, darker green above, paler green below; base attenuate; apex acute; margin revolute when dry; midvein prominent or invisible above, always prominent below; secondary veins invisible or 1–2 on each side of the midvein; intersecondaries invisible. Inflorescences terminal, compound dichasia, several-flowered; peduncle 0–12 mm long, glabrous. Pedicels (0.7–) 3– 9.5 mm long, scabrate. Flowers probably heterostylous (only flowers with anthers exserted and style included were observed). Calyx green; tube reduced; lobes 4, triangular, 0.7–1 × 0.4–0.6 mm, glabrous to scabrate. Corolla white; tube funnel-shaped, 1.5–1.7 mm long, glabrous outside and pubescent inside; lobes 4, ovate, 1.5–1.6 × 0.8–1 mm, glabrous. Stamens inserted near the base of the corolla lobes and exserted for ca 2 mm beyond the corolla throat. Anthers ellipsoid, 0.8–1 mm long; filaments dorsifixed, 1.4–1.7 mm long. Pollen tricolporate. Ovary 2-locular, broadly obovoid to broadly depressed obovoid, 0.5–0.7 × 0.7–1 mm, glabrous; placenta attached near the middle of the septum, stalked, globose, bearing few (3–4) ovules per locule. Style 1.2–1.3 mm long, included, glabrous; stigma bilobed, lobes 0.3–0.4 mm long, papillate to hirtellous. Capsules broadly depressed obovoid, well-developed beak, 1.2–1.4 × 2.3–2.7 mm, crowned with the persistent calyx lobes, glabrous, dehiscence loculicidal. Seeds few (2–3), elliptic in outline, ventral groove present, 0.8–1 × 0.6–0.8 mm, black; seed coat surface reticulate, microsculpturing favulariate.

Distribution

SE Madagascar: Toliara province, Anosy region, Taolanaro district.

Habitat

Humid forest; laterite and granite substrate; at 830 m elevation.

Conservation status

Known from only one locality. Given its apparent rarity and following the recommendation of Callmander et al. (2005) to avoid the Data Deficient category, we consider the species as vulnerable (VU D2) based on its restricted area of occupancy (D2) and the high human pressure present in the entire area resulting in a general decline of suitable habitats (humid forest) for the species.