Panicum ambositrense A. Camus
Creators: name: Vorontsova, Maria S.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Poales
Poaceae
Panicum
Panicum ambositrense

description: 2. Panicum ambositrense A. Camus in Bull. Soc. Bot. France 72: 370. 1925.
Lectotypus (designated here): MADAGASCAR. Prov. Fianarantsoa: env. d’Ambositra, 1700 m, V.1912, Perrier de la Bâthie 10851 (P [P00450276]!;: K!). Syntypus: MADAGASCAR. Prov. Antsiranana: Tsaratanana, IV.1923, Perrier de la Bâthie 16365 (P [P02251335, P02251348]!).
Prostrate perennial, branched, the long thin culms rooting at nodes, to 2 m long, the culms and nodes glabrous. Leaf sheaths glabrous. Ligule a glabrous or ciliolate membrane. Leaf blades linear to linear-lanceolate, flat, chartaceous, 5 –13 × 0.3– 1 cm, drying yellow-green, glabrous to pubescent on both sides. Panicles terminal, partly or fully exserted 10–25 cm long, broadly ovate, diffuse, the branches opening at right angles to the main axis, glabrous, the spikelets clustered at branch apices, the pedicels 3–5 mm long. Spikelets lanceolate, apically acuminate, 2–2.5(– 2.7) mm long, with prominent veins, green to purple, opening only partly. Lower glume equalling the spikelet or almost as long, chartaceous, apically acuminate, 3-veined, glabrous or rarely pubescent. Upper glume as long as the spikelet, herbaceous, apically acuminate, 5–7-veined, glabrous or rarely pubescent. Lower floret barren, with a reduced palea. Lower lemma herbaceous, 5-veined, glabrous or rarely pubescent. Upper lemma somewhat shorter than the lower floret, smooth, shiny, pale.
Distribution and ecology. – Endemic to the central high plateau and high elevation areas in northern Madagascar (Fig. 2A), 1250–2000 m. Wet gallery forest understory, usually beside streams.
Notes. – This common species can be distinguished from the similar and likely related P. perrieri A. Camus by its shorter spikelets (2.5–3(–3.2) mm long in P. perrieri) and an open panicle (contracted in P. perrieri). Panicum ambositrense and P. perrieri share long lower glumes and acuminate spikelets and are close to the African P. aequinerve Nees which has larger spikelets than P. ambositrense and differs from P. perrieri by its open branched panicle. CLAYTON & RENVOIZE (1982) incorrectly cite P. aequinerve from Madagascar: this is a record of P. ambositrense.
Perrier de la Bâthie 10851 is chosen to be the lectotype due to the more broad distribution of duplicates than the other syntype collection, Perrier de la Bâthie 16365 held only at P [P 02251348, P 02251335].
This species is illustrated in BOSSER (1969: Fig. 122).
Additional material examined. – MADAGASCAR. Prov. Antananarivo: Manjakatompo, II.1953, Bosser 4850 (P [P02251340]); ibid. loco, II.1953, Bosser 4853 (TAN); La Mandraka, II.1953, Bosser 5008 (TAN); Faratsiho, I.1955, Bosser 7621 (P [P02307398], TAN); La Mandraka, II.1953, Bosser 8009 (P [P02251334]); Ramainandro, face W de l’Ankaratra, II.1957, Bosser 10817 (P [P02251241], TAN); Ambatovory-Nandihizana, Ambatovory, IV.1957, Bosser 11009 (P [P02251345]); Angavokely, III.1959, Bosser 12730 (TAN); ibid. loco, I.1960, Bosser 13719 (TAN); Ambatolaona, 15.V.1935, Herb. Jard. Bot. Tan. 32423 (P [P02251336], TAN); Angavokely, 25.VI.1964, Tateoka 3519 (P [P02726869], TAN); Manjakatompo, 24.V.1950, Vaughan s.n. (K [K000805440]); Manerinerina, Analamaintso forest, 17°57'31"S 47°07'30"E, 13.II.2013, Vorontsova et al. 907 (K, TAN). Prov. Antsiranana: near summit d’Ambre, 12°35'S 49°09'E, 9.IV.1993, Andrianantoanina et al. 49 (K [K000805443], P [P06795995]); montagne d’Ambre, 12°35'47"S 49°09'34"E, 10.XI.2007, Gautier & Nusbaumer 5188 (G [G00075803]); from Mangindrano up Maromokotro, 11.V.1974, Gentry 11674 (K [K000805441], P [P02251242]); massif de Marivorahona au SW de Manambato, 18.III.1951, Humbert & Capuron 25692 (K [K000805552], P [P01914209], TAN). Prov. Fianarantsoa: Itremo, Ambatomaneloka, IX.1956, Bosser 9949 (TAN); Andringitra, IV.1964, Bosser 19435 (P [P03487900], TAN); 34 km N of Fianarantsoa, 28.I.1975, Croat 29960 (TAN); Ambohimitombo, 1.X.1895, Forsyth-Major 267 (K [K000805605]); Anjavidilava Est-Andingitra, 11.I.1971, Guillaumet 3701 (P [P02325400], TAN); Itremo, Antsirakambiaty, 20°35'47"S 46°33'45"E, 18.II.2014, Nanjarisoa et al. 138 (K, TAN); Ambositra, Perrier de la Bâthie 34 (K [K000805604]); ibid. loco, V.1912, Perrier de la Bâthie 10851 (K, P [P00450276]); Itremo, Antsirakambiaty, 20°35'42"S 46°33'47"E, 12.III.2012, Vorontsova et al. 736 (K, TAN). Prov. Mahajanga: Bealanana, Ankaizina, V.1962, Bosser 2536 (TAN). Prov. Toamasina: Périnet, II.1955, Bosser 7775 (P [P02251338]); ibid. loco, 25.II.1975, Croat 32262 (TAN); Analamazaotra, X.1936, Herb. Jard. Bot.Tan. 2166 (P [P02251346]); ibid. loco, Perrier de la Bâthie 10922 (K [K000244679], P [P02251343]); ibid. loco, Perrier de la Bâthie 10925 (K [K000805442], P [P02251337], TAN).
description: Published as part of Vorontsova, Maria S., 2018, Revision of the group previously known as Panicum L. (Poaceae: Panicoideae) in Madagascar, pp. 143-186 in Candollea 73 (2) on page 148, DOI: 10.15553/c2018v732a1, http://zenodo.org/record/5724514