Panicum subalbidum Kunth, Révis. Gramin.

Vorontsova, Maria S., 2018, Revision of the group previously known as Panicum L. (Poaceae: Panicoideae) in Madagascar, Candollea 73 (2), pp. 143-186 : 176

25. Panicum subalbidum Kunth, Révis. Gramin. 2: 397, tab. 112. 1831.

Holotypus: SENEGAL: Dagana , Walo , IX.1825, Leprieur s.n. ( P [ P00442196 ]!) .

= Panicum proliferum var. longijubatum Stapf, Fl. Cap. 7: 406. 1899. ≡ Panicum longijubatum (Stapf) Stapf in Oliv. et al., Fl. Trop. Afr. 9: 718. 1920. Syntypi: SOUTH AFRICA. Coast Reg.: Komgha division , Kei Riv ., near Komgha , s.d., Flanagan 953 ( K [ K000255495 ]!). Eastern Reg. : Natal , near Umzimkulu Riv ., 1840, Drège s.n. ( K [ 000255493 ]!). Eastern Reg.: near Umpumulo , s.d., Buchanan 267 ( K [ K000255494 ]!) ; near Durban , Williamson 21 ( K [ K000255491 ]!) .

= Panicum bicuspidatum A. Camus in Bull. Soc. Bot. France 99: 64. 1952. Holotypus: MADAGASCAR. Prov. Antsiranana: Ankarana, XII.1937 – I.1938, Humbert 18855 ( P [ P00450278 ]!), syn. nov.

Erect or geniculately ascending perennial, in diffuse tufts, 0.4 – 1 m tall, the culms spongy, glabrous, the nodes dark. Leaf sheaths glabrous. Ligule a ciliolate membrane. Leaf blades linear, flat, chartaceous, 7–10 × 0.3–1.5 cm, drying yellowgreen, glabrous on both sides. Panicles terminal, partly or fully exserted, 15–40 cm long, effuse, the branches contracted, the lower branches opening and somewhat reflexed at maturity, scabrous, the spikelets appressed to the branches on pedicels 0.5–3 mm long. Spikelets ovate to lanceolate, apically acute, 2.5–3 mm long, with prominent veins, white to yellow, sometimes with purple, almost never gaping open. Lower glume c. ¼ as long as the spikelet, membranous, cuff-like, obtuse to finely acute, 1-veined, glabrous. Upper glume as long as the spikelet, herbaceous, 7–9-veined, glabrous. Lower floret barren, with a reduced palea. Lower lemma herbaceous, 7–9-veined, glabrous. Upper lemma 2–2.2 mm long, shorter than the lower floret, smooth, shiny, pale.

Distribution and ecology. – Common African grass found across Madagascar except the north of the island, usually near water, on the edges of rice paddies, 0 – 1500 m ( Fig. 16A ). Occasionally recorded from La Réunion and Mauritius.

Notes. – This species is recognisable by its pointed spikelets that gape open at maturity, its reduced lower glume, dark nodes, and frequently geniculate growth habit.

The full typification of Panicum subalbidum Kunth is outside the scope of this work and will be published as part of an ongoing study of African Panicum s.l.

This species is illustrated in BOSSER (1969: Fig. 127e-h).

Additional material examined. – MADAGASCAR. Prov. Antananarivo: parc de Tsimbazaza , 9.XII.1952, Benoist 1925 ( P [ P 03182760 ]) ; PK 22 rte d’Arivonimamo , V.1963, Bosser 17064 ( P [ P 02726854 ]) ; Antananarivo Ville, aérodrome Ivato , 18. I.1975, Croat 28738 ( TAN) ; Sansoavy, Fenoarivo-Centre , 30. XI.1966, Delhaye 15956 ( P [ P 06768787 ]) ; aérodrome Ivato , 7. I.1967, Delhaye & Granier 16816 ( P [ P 02608204 ]) ; Nanisana , II.1906, Herb. Jard. Bot. Tan. 772 ( P [ P 02608214 ]) ; ibid. loco, 31. I.1933, Herb. Jard. Bot.Tan. 32483 ( P [ P 02608216 ]) ; parc de Tsimbazaza , 18.VIII.1935, Herb. Jard. Bot. Tan. 324193 ( P [ P 02040429 ]) ; central Madagascar, Parker s.n. ( K [ K000805581 ]) ; Antsirabe, I.1924, Perrier de la Bâthie 10757 ( P [ P02608174 ]) ; Lac Itasy, 19°03'45"S 46°44'36"E, 3.II.2000, Raynal-Roques et al. 24919 ( K [ K000805573 ]) ; env. de Antananarivo, 25.IV.1907, Rotereau s.n. ( P [ P02358113 ]) ; ibid. loco, 25.VI.1960, Rotereau s.n. ( P [ P02373565 ]) . Prov. Fianarantsoa: station de Belemboka , Anon. 27397 ( P [ P02608203 ]) ; Vohipeno, X.1990, Beaujard 322 ( P [ P06768788 ]) ; Ranohira, II.1956, Bosser 9023 ( P [ P02608210 ]) ; ibid. loco, II.1963, Bosser 17883 ( P [ P02608171 ]) ; Sakaleona, Lac Alaotra, Cours s.n. ( P [ P02726882 ]) ; W of Ambalavao, 1.II.1975, Croat 30236 ( TAN) ; Ambohimitombo forest, V.1895, Forsyth-Major 248 ( G, K [ K000805577 ]) ; ibid. loco, 26.I.1895, Forsyth-Major 734 ( K [ K000805576 ]) ; Betsiléo, II.1881, Hildebrandt 4012 ( G, K [ K000805575 ], P [ P02608195 ]) ; Isalo, haute vallée de la Mama , 29.I.1955, Humbert 28779 ( P [ P02608198 ]) ; PK 40 on RN 27 , 21.XII.1965, Peltier & Peltier 5568 ( P [ P02726870 ]) ; 4 km from Vangaindrano towards Taolagnaro, 23°21'17"S 47°36'40"E, 30.X.2011, Vorontsova et al. 637 ( K, TAN) ; RN25 from Irondro to Ambolotara , 21°23'12"S 47°56'19"E, 4.XI.2011, Vorontsova et al. 708 ( K, TAN) . Prov. Mahajanga: Marovoay , 13.VI.1912, Afzelius G46 ( K [ K000805578 ]) ; ibid. loco, 13.VI.1912, Afzelius s.n. ( K [ K000805574 ]) ; Befandriana, Angodrogodro-baiba , 17.XII.1942, Herb. Jard. Bot. Tan. 5552 ( P [ P02608209 ]) ; haute vallée de la Sofia vers Antsakabary , XI.1937, Humbert 18075 ( G, P [ P02608207 ]) ; rte Majunga , Marovay , IV.1967, Morat 2713 ( P [ P02608164 ]) ; env. de Maevatanana , VII.1900, Perrier de la Bâthie 895 bis ( P [ P02608196 ]) ; Iabohazo riv ., affluent de gauche du Betsiboka , VII.1902, Perrier de la Bâthie 11106 ( P [ P02263079 ]) ; Andranomavo, Soalala , 24.II.1953, Réserves Naturelles 5100 ( P [ P02608200 ]) ; ibid. loco, 8.II.1955, Réserves Naturelles 7098 ( P [ P02608166 ]) ; Antanimbary, near Maevatanana , 17°11'S 46°51'E, 13.II.2013, Vorontsova et al. 913 ( K, TAN) ; Majunga, VII.1922, Waterlot 549 ( P [ P02608212 ]) . Prov. Toamasina: Sainte Marie, 1847, Boivin 1622 ( K [ K000805572 ], US) ; ibid. loco, 1850, Boivin s.n. ( K [ K000805584 ]) ; Mahanoro, Anosivolo , 20°00'33"S 48°17'49"E, 11.II.2010 Faranirina et al. 173 ( P [ P06768784 ]) ; lac Alaotra , Herb. Jard. Bot. Tan. 3393 ( P [ P02608173 ]) ; Ambatondrazaka, 8.III.1932, Herb. Jard. Bot. Tan. 324149 ( P [ P02608172 ]) ; ibid. loco, III.1932, Herb. Jard. Bot. Tan. 324162 ( P [ P02608211 ]) ; Ivoloina, VII.1930, Martine G14 ( P [ P02608202 ]) ; Mahanoro, rivière alimentée Mangoro , 20°00'32"S 48°17'47"E, 8.II.2010, Rakotovao et al. 5176 ( P [ P06768525 ]) . Prov.Toliara: Beloha – Tsihombe , II.1962, Bosser 15657 ( P [ P02608163 ], TAN) ; banks of Onilahy riv ., near Tongobory , 14.II.1975, Croat 31199 ( TAN) ; Andohahela NP , Fanota , 24°46'31"S 46°51'53"E, 2.XI.2011, Hall et al. 63 ( K, TAN) ; massif de l’Ivakoany , XI.1933, Humbert 12257 ( US) ; forêt d’Analavelona au N du Fiherenana , III.1934, Humbert 14266 ( P [ P02608199 ]) ; vallée de l’Onilahy en aval de Tongobory , 8.XI.1960, Leandri & Chauvet 3733 ( P [ P02608222 ]) ; ibid. loco, 8.XI.1960, Leandri & Chauvet 3748 ( P [ P02608197 ]) ; Morondava, X.1963, Morat 152 ( P [ P02608220 ]) ; bords du Manambolo, X.1904, Morat 737 ( P [ P02608218 ]) ; piste de Sakaraha à Ankazoabo après Laborano , II.1968, Morat 2882 ( P [ P02608219 ]) . Sine loco: Anon. 23 ( P [ P02608213 ]) ; Masobisilay, Anon. 31 ( P [ P02608167 ]) ; Cours s.n. ( P [ P02329564 ]) ; 1956, Dequaire 27397 ( P [ P06795991 ]) .

Figures

Fig. 16. – Distribution maps. A. Panicum subalbidum Kunth (stars), P. subhystrix A. Camus (triangles), P. trichocladum K. Schum. (circles) and P. voeltzkowii Mez (squares); B. Panicum vohitrense A. Camus (stars), Trichanthecium brazzavillense (Franch.) Zuloaga & Morrone (triangles), T. parvifolium (Lam.) Zuloaga & Morrone (circles) and Urochloa maxima (Jacq.) R.D. Webster (squares).