Panicum spergulifolium A. Camus in Bull. Soc. Bot. France 72: 619. 1925

Vorontsova, Maria S., 2018, Revision of the group previously known as Panicum L. (Poaceae: Panicoideae) in Madagascar, Candollea 73 (2), pp. 143-186 : 172-176

24. Panicum spergulifolium A. Camus in Bull. Soc. Bot. France 72: 619. 1925 ( Fig. 13A , 14 , 15 ).

Lectotypus (designated here): MADAGASCAR. Prov. Fianarantsoa: Andringitra massif , II.1922, Perrier de la Bâthie 14551 ( P [ P02263099 ]!; isolectotype: G [ G00022432 ] image seen) . Syntypi: MADAGASCAR. Prov. Fianarantsoa: Andringitra massif , I.1922, Perrier de la Bâthie 14334 ( P [ P00224783 , P02263106 ]!) ; Andringitra massif , II.1921, Perrier de la Bâthie 14413 ( G [ G00022433 ], K [ K000244714 , K000244715 ]!, P [ P00224777 , P02263100 ]!) .

Mat-forming perennial, much branched, to 40 cm tall, the culms and nodes glabrous. Leaf sheaths glabrous to sparsely ciliate. Ligule a ciliolate membrane. Leaf blades lanceolate, flat or rolled, coriaceous, 0.4–3(–5) × 0.1–0.2 cm, drying redbrown, imbricate, appressed or ascending, glabrous to sparsely ciliate, sometimes with bulbous based cilia on the lower part of the margin. Panicles terminal, fully exserted on a peduncle 6–20 cm long, 1.5–4(–7) cm long, obovate, few-flowered, the branches wiry, contracted or partly open, glabrous. Spikelets elliptic, apically obtuse, 2.8–3 mm long, with poorly visible veins, purplish, opening only partly. Lower glume 2/3– 3/4 as long as the spikelet, chartaceous, apically subacute, 3-veined, glabrous. Upper glume 3/4 as long as the spikelet, herbaceous, 3– 5-veined, glabrous. Lower floret male, with palea. Lower lemma herbaceous, 5-veined, glabrous. Upper lemma smooth, shiny, pale.

Distribution and ecology. – Unique to high elevation plateau of Andringitra and surrounding area, in damp areas on rocks, sheltered under rocks, or in open areas with sandy soils, 1700–2600 m ( Fig. 10B ).

Notes. – This species is dominant across much of the high elevation plateau in Andringitra. There is considerable morphological variability: sheltered populations at higher elevations and with more access to water have longer leaf blades which are more likely to be flat, and larger panicles with open branches. Populations that form ground cover in drier, more open, lower elevation habitats have a denser compact habit with shorter rolled leaf blades, and more condensed panicles with fewer spikelets. Variation appears to be continuous.

The lectotype is chosen for its high quality flowering material and the best distribution of duplicates.

Additional material examined. – MADAGASCAR. Prov. Fianarantsoa: Andringitra NP, 22°10'03"S 46°53'49"E, 25.XI.2009, Couch et al. 590 ( K [ K000805562 ]) ; Manjarivolo , 2.XI.1970, Guillaumet 3501 ( P [ P06768509 ]) ; Andohariana in Andringitra , 13.I.1971, Guillaumet 3731 ( P [ P06768506 ]) ; N des chaînes Anosiennes , 25.XI.1971, Guillaumet 3921 ( P [ P06768507 ]) ; massif de l’Andringitra , 27.XI.1924, Humbert 3879a ( K [ K000805567 ]) ; ibid. loco, 27.V.1924, Humbert 3880 ( G, K [ K000805563 ], P [ P02263105 ]) ; ibid. loco, 27.V.1924, Humbert 3881 ( G, K [ K000805570 ], NY, P [ P00224782 ]) ; ibid. loco, 27.XI.1924, Humbert 3882 ( P [ P02263101 ]) ; ibid. loco, XII.1924, Humbert 3883 ( G, K [ K000805568 ], NY, P [ P00224781 ]) ; Andringitra NP , près du campement 2 , 22°09'24"S 46°54'19"E, 26.XI.2013, Nanjarisoa et al. 74 ( K, TAN) ; Andringitra NP , Pic Boby , 22°11'42"S 46°53'31"E, 28.XI.2013, Nanjarisoa et al. 86 ( K, TAN) ; Andringitra massif , II.1922, Perrier de la Bâthie 14549 ( K [ K000244713 ], P [ P00224784 ]) ; Andringitra NP , 22°09'00"S 46°53'57"E, 6.XI.2003, Phillipson et al. 5679 ( P [ P06768783 ]) ; Sendriosa, Ambalavaokely , 5.XII.1954, Rakotovao 688 ( P [ P06903358 ]) ; Ambalavao, Ramiova , 28.X.1955, Rakotovao 7632 ( P [ P06768508 ]) ; Andringitra, Diavolana , 6 km from camp 2, 22°08'13"S 46°52'00"E, 29.XI.2013, Vorontsova et al. 1218 ( TAN) ; Andringitra, below Imarivolanitra , 22°11'42"S 46°45'31"E, 12.XII.2013, Vorontsova et al. 1228 ( TAN) ; Andringitra , east of camp 3 , 22°11'32"S 46°54'20"E, 13.XII.2013, Vorontsova et al. 1250 ( TAN) ; ibid. loco, 13.XII.2013, Vorontsova et al. 1262 ( TAN) .

Figures

Fig. 13. – A. Habitat of Panicum spergulifolium A. Camus with P. spergulifolium pink at the forefront; B. Habitat of P. voeltzkowii Mez with the green-brown mat of P. voeltzkowii across the forefront; C. Panicum subhystrix A. Camus; D. Panicum vohitrense A. Camus. [A: Vorontsova et al. 1218; B: Vorontsova et al. 1391; C: Ratovonirina et al. 185; D: Vorontsova & Onjalalaina 1466] [Photos: M.S. Vorontsova]

Fig. 14. – Panicum spergulifolium A. Camus, low elevation morphotype. A. Habit; B. Leaf; C. Ligule area; D. Panicle branch; E. Spikelet; F. Lower glume; G. Upper glume; H. Spikelet with glumes removed; I. Lower lemma, dorsal view; J. Lower lemma, ventral view; K. Spikelet with glumes and lower lemma removed; L. Upper lemma, ventral view; M. Upper floret, lateral view; N. Upper lemma, ventral view; O. Upper palea, ventral view; P. Upper palea, dorsal view. [Nanjarisoa et al. 74, K] [Drawing: Lucy T. Smith]

Fig. 15. – Panicum spergulifolium A. Camus, high elevation morphotype. A. Habit; B. Ligule; C. Panicle branch; D. Lower glume, dorsal view; E. Lower glume, ventral view; F. Upper glume, dorsal view; G. Upper glume, ventral view; H. Lower lemma, dorsal view; I. Lower lemma, ventral view; J. Lower palea; K. Upper lemma, dorsal view; L. Upper lemma, ventral view; M. Upper palea, dorsal view; N. Upper floret, the lemma removed. [Vorontsova et al. 1218, K] [Drawing: Lucy T. Smith]

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).