Astiella antongilensis Groeninckx & Janssens & Smets & Verstraete 2017, sp. nov.
Creators: name: Groeninckx, Inge
name: Janssens, Steven
name: Smets, Erik
name: Verstraete, Brecht
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Rubiaceae
Astiella
Astiella antongilensis

description: Astiella antongilensis Groeninckx sp. nov.
http://www.ipni.org/urn:lsid:ipni.org:names:77161710-1
Figs 1, 2A
Diagnosis
Astiella antongilensis sp. nov. resembles A. homolleae sp. nov. and A. perrieri sp. nov. in having a reduced corolla tube and numerous ovules per locule, but differs in having a pubescent stem, large leaves that are covered with trichomes below, and pubescent flowers.
Etymology
The epithet refers to Antongil Bay, the largest bay in Madagascar and the area where the species is found.
Type
MADAGASCAR: Toamasina province, Analanjirofo region, Maroantsetra district. Côte est, environs de la baie d’Antongil, bois, 200 m, Oct. 1912, Perrier de la Bâthie 3749 (holo-: P, P 00219825; iso-: P, P 00516317).
Description
Annual herb, ca 10 cm tall; stems quadrangular in cross section, pubescent. Stipule base 1–2 mm long, pubescent; fimbriae 3–6, 1– 2 mm long, colleter-tipped. Leaves petiolate; petiole 5–15 mm long, pubescent; blades elliptic, slightly ovate or obovate, (12–)45–72 × (6–) 10–26 mm, very sparsely covered with trichomes particularly on the veins above, more densely covered with trichomes below; base attenuate; apex acute or obtuse; margin ciliolate; midvein prominent particularly below; secondary veins 4–7 on each side of the midvein; intersecondaries invisible. Inflorescences terminal, multi-flowered; peduncle 0–40 mm long, pubescent. Pedicels 1–7 mm long, pubescent. Flowers heterostylous (but both style and anthers exserted). Calyx green; tube reduced; lobes 4, narrowly triangular or triangular, 1–1.3 × 0.4–0.5 mm, pubescent. Corolla white or pale purple; tube reduced, 0.2–0.5 mm long; lobes 4, somewhat spathulate, 2.1–2.8 mm long, 0.5–0.6 mm wide at the base, 1–1.2 mm wide at the top, pubescent outside, papillate inside. Stamens inserted near the base of the corolla lobes and exserted for 2.2–3.2 mm beyond the corolla throat. Anthers ellipsoid, 1.2–1.4 mm long; filaments dorsifixed, ca 3.3 mm long in brevistylous flowers, ca 1.2 mm long in longistylous flowers. Pollen unknown. Ovary 2-locular, broadly obovoid, 1–1.2 × 1–1.3 mm, densely pubescent; placenta attached above the middle of the septum, stalked, elongated, bearing numerous ovules per locule. Style ca 3.3 mm long in longistylous flowers (exserted for ca 3 mm beyond the corolla throat), ca 2.5 mm long in brevistylous flowers (exserted for ca 2.2 mm beyond the corolla throat), glabrous; stigma bilobed, lobes 0.6–1 mm long, papillate. Capsules broadly obovoid or broadly depressed obovoid, 2.5–3 × 2.5–3 mm, crowned with the persistent calyx lobes, pubescent, dehiscence loculicidal. Seeds unknown.
Distribution
E Madagascar: Toamasina province, Analanjirofo region, Maroantsetra district.
Habitat
Humid forest; at 200 m elevation.
Conservation status
The species is only known from its type collected in 1912. There is no detailed information about the locality where the specimen was collected. 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.
description: Published as part of Groeninckx, Inge, Janssens, Steven, Smets, Erik & Verstraete, Brecht, 2017, Description of 11 new Astiella (Spermacoceae, Rubiaceae) species endemic to Madagascar, pp. 1-40 in European Journal of Taxonomy 312 on pages 4-7, DOI: 10.5852/ejt.2017.312, http://zenodo.org/record/3827336