Panicum luridum Hack. in J. Linn. Soc., Bot. 29: 64. 1891

Vorontsova, Maria S., 2018, Revision of the group previously known as Panicum L. (Poaceae: Panicoideae) in Madagascar, Candollea 73 (2), pp. 143-186 : 164

17. Panicum luridum Hack. in J. Linn. Soc., Bot. 29: 64. 1891 ( Fig. 6C ).

Lectotypus (designated here): MADAGASCAR. Prov. Antananarivo: Antananarivo (interior), s.d., Scott Elliot 1745 ( W [ W1916-0019398 ] image seen; isolectotype: E [ E00200284 ] image seen, K [ K000244704 ]!, P [ P00450228 ]!, US [ US00148261 ]!) .

Stoloniferous perennial, usually geniculately ascending, often with a hardened underground part, to 40 cm tall, the stems and nodes glabrous. Leaf sheaths glabrous to pilose. Ligule a line of hairs. Leaf blades linear to lanecolate, flat, firm, 2–10 × 0.2–0.5 cm, drying yellow-green, glabrous to pilose on both sides sometimes with bulbous based cilia on the lower part of the margin. Panicles terminal, fully exserted, 4–7 cm long, ovate, the branches appressed to ascending, glabrous. Spikelets broad, apically acute, 1.8 –2.5 mm long, pale brown or purplish, gaping open at maturity. Lower glume c. ½ as long as the spikelet, keeled, apically finely acuminate, 3-veined, finely scabrous on the keel. Upper glume as long as the spikelet, herbaceous, 5-veined, glabrous. Lower floret male, with palea. Lower lemma herbaceous, 5-veined, glabrous. Upper lemma smooth, shiny, pale.

Distribution and ecology. – Endemic to Madagascar’s High Plateau and the env. of Mahajanga, in open grassland, savanna, tapia forest, and disturbed vegetation, often on sand, 0–1600 m ( Fig. 10A ).

Notes. – This species is not known in coastal regions except for Mahajanga. The species boundaries with both P. cinctum and P. voeltzkowii are somewhat complex. It has larger spikelets than P. voeltzkowii ; the spikelets also more acute while being obtuse in the other two.

The sheet W [ W1916-0019398 ] is from Hackel’s own herbarium with his original handwriting which is why it is has been chosen to be the lectotype.

This species is illustrated in BOSSER (1969: Fig. 125a-e).

Additional material examined. – MADAGASCAR. Prov. Antananarivo: Nanisana , V.1905, Alleizette 190 ( P [ P02207837 ]); Ibity, 20°04'06"S 47°00'10"E, 26.II.2008, Andriamahay & Rakotoarisoa 1892 ( K [ K000805492 ]); Central Madagascar, Baron 633 ( K [ K000805488 ]); Analabe, VI.1951, Bosser 571 ( P [ P02726880 ], TAN); ibid. loco, VI.1951, Bosser 577 ( TAN); Manjakandriana , V.1952, Bosser 646 ( P [ P02309304 ], TAN); Antananarivo, V.1951, Bosser 711 ( TAN); Arivonimamo , V.1951, Bosser 1161 ( TAN); env. d’Ambatolampy , II.1953, Bosser 4797 ( P [ P02207838 ]); Analabe, III.1953, Bosser 5209 ( P [ P02207835 ], TAN); PK 50 rte de Majunga , II.1954, Bosser 7421 ( TAN); Ambohimandroso , XII.1955, Bosser 8885 ( P [ P02207850 ]); Andramasina, II.1958, Descoings 3028 ( TAN); Antananarivo, Herb. Jard. Bot.Tan. 913 ( P [P02207829], TAN); Nanisana, bord du chemin d’Anjanahary , 3.II.1933, Herb.Jard. Bot.Tan. 32457 ( P [ P02207836 ], TAN); W de Tsiroanomandidy, XII.1974, Morat 4783 ( P [ P02207841 ], TAN); Central Madagascar, Parker s.n. ( K [ K000805486 ]); Andranomena , 19°01'03"S 47°13'30"E, 12.III.2011, Ramahefaharivelo et al. 397 ( P [ P06795472 ]); Ambohitantely, Manankazo , 5.II.1948, Réserves Naturelles 1462 ( P [ P02207834 ]) ; Ilafy , 20.VI.1907, Rotereau s.n. ( P [ P02373568 ]) ; Antananarivo, 29.III.1950, Service de l’ Agriculture 111 ( TAN) ; Imerintsiatosika, Service de l’ Agriculture 395 ( TAN) ; Analamaintso forest , 17°57'31"S 47°07'30"E, 13.II.2013, Vorontsova et al. 909 ( K, TAN) . Prov. Antsiranana: Manongarivo , X.1903, Perrier de la Bâthie 11101 ( P [ P02325393 ]) . Prov. Fianarantsoa: Ibeoaka , XII.1952, Bosser 1485 ( TAN) ; Fianarantsoa, XII.1951, Bosser 1588 ( TAN) ; Horombe , II.1965, Morat 2021 ( TAN) ; Itremo, Ampangabe , 20°36'53"S 46°37'11"E, 16.III.2013, Nanjarisoa et al. 24 ( K, TAN) ; Itremo, Mandimbizaka , 20°35'46"S 46°18'51"E, 14.II.2014, Nanjarisoa et al. 98 ( K, TAN) ; env. de Fianarantsoa , V.1912, Perrier de la Bâthie 10863 ( P [ P02325391 ]) ; Itremo, Antsirakambiaty , 20°35'42"S 46°33'47"E, 12.III.2012, Vorontsova et al. 741 ( K, TAN) . Prov. Mahajanga: forêt d’Antsahanitia , 15°34'34"S 46°25'30"E, 23.IV.2009, Andriamahay & Rakotoarisoa SNGF 2238 ( TAN) ; Beronono, Tsaramandroso , XI.1951, Bosser 1885 ( P [ P02207833 ]) ; ibid. loco, XI.1951, Bosser 1888 ( TAN) ; entre Ambalakidy et Ambalabe , VI.1953, Bosser 5473 ( TAN) ; env. de Majunga , VI.1953, Bosser 5755 ( P [ P02207847 ], TAN) ; Maevatanana , 26.XII.1941, Decary 17031 ( P [ P02207803 ]) ; riv. du Mahajamba , au dessus de Beronono , I.1907, Perrier de la Bâthie 11143 ( P [ P02207848 ]) ; près de Majunga , III.1927, Perrier de la Bâthie 17950 ( K [ K000805490 ], P [ P02207851 ]) . Prov. Toamasina: Andilamena , N lac Alaotra , 1952, Bosser 979 ( TAN) ; Morarano , XII.1954, Bosser 7467 ( TAN) ; ibid. loco, XII.1964, Bosser 7468 ( P [ P02207832 ]) ; ibid. loco, XII.1954, Bosser 7470 ( TAN) ; ibid. loco, XII.1954, Bosser 7471 ( P [ P02251455 ], TAN) ; Andilamena , V.1953, Bosser s.n. ( P [ P02726868 ]) ; Ambatondrazaka , II.1933, Herb. Jard. Bot.Tan. 324104 ( P [ P02207830 ]) ; ibid. loco, III.1932, Herb. Jard. Bot. Tan. 324129 ( TAN) ; Ambodivoaro , III.1932, Herb. Jard. Bot.Tan. 324143 ( P [ P02207831 ], TAN) ; Analamazaotra , Perrier de la Bâthie 10923 ( P [ P02207846 ]) ; Manakambahiny , 24.XII.1962, Réserves Naturelles 12361 ( P [ P06795993 ]) . Prov. Toliara: SW de Ankazoabo , 20.II.1970, Bosser 19946 ( K [ K000805594 ], P [ P02222319 ]) ; piste d’Ankazoabo à Befandriana , II.1968, Morat 2874 ( TAN) . Sine loco: Methuen s.n. ( K [ K000805496 ]) .

Figures

Fig. 6. – A. Panicum cupressifolium A. Camus; B. Panicum ibitense A. Camus; C. Panicum luridum Hack.; D. Panicum mitopus K. Schum. [A: Nanjarisoa et al. 87; B: Letsara et al. 2047; C: Rakotoarisoa & Randrianavosoa SNGF 2931; D: Vorontsova et al. 2110] [Photos: A–B, D:M.S. Vorontsova; C: S. Rakotoarisoa]

Fig. 10. – Distribution maps. A. Panicum luridum Hack. (stars), P. manongarivense A. Camus (triangles), P. mitopus K. Schum. (circles) and P. novemnerve Stapf (squares); B. Panicum palackyanum A. Camus (stars), P. perrieri A. Camus (triangles), P. pleianthum Peter (circles) and P. spergulifolium A. Camus (squares).