Panicum cupressifolium A. Camus in Bull. Soc. Bot. France 72: 372. 1925

Vorontsova, Maria S., 2018, Revision of the group previously known as Panicum L. (Poaceae: Panicoideae) in Madagascar, Candollea 73 (2), pp. 143-186 : 158

9. Panicum cupressifolium A. Camus in Bull. Soc. Bot. France 72: 372. 1925 ( Fig. 6A , 7 ).

Lectotypus (designated here): MADAGASCAR. Prov. Fianarantsoa: Andringitra massif , II.1921, Perrier de la Bâthie 14548 ( P [ P00224765 ]!; isolectotype: E!, EA!, G [ G00022443 ], K [ K000244691 , K000244692 , K000244693 , K000244694 , K000244695 ]!, MO!, P [ P00224764 , P00462677 ]!, PRE [ PRE0031827 -0]!, S [S-G-4484] image seen, SI!, TAN!, US [ US00147793 , US00148388 ]!) . Syntypus: Andringitra massif , 2.V.1911, Perrier de la Bathie 10833 ( K [ K000244697 ]!, P [ P00462676 , P00224767 , P00462675 ]!), TAN !).

Woody perennial, much branched, the main stems lignified, to 50 cm tall, the culms and nodes glabrous. Leaf sheaths glabrous. Ligule absent. Leaf blades scale-like, ovate, flat, coriaceous, 0.05–0.3 × 0.05–0.2 cm, drying red-brown, imbricate, appressed, glabrous on both sides, often larger on the central stem. Spikelets terminal, rare and difficult to find, single at branch apices or rarely up to three together, nodding, elliptic, apically obtuse, c. 2.5 mm long, with poorly visible veins, whitish to purple, opening only partly. Lower glume c. ½ as long as the spikelet, chartaceous, apically obtuse, 3-veined, glabrous. Upper glume 3/4 as long as the spikelet, herbaceous, 3–5-veined, glabrous. Lower floret barren, with a reduced palea. Lower lemma herbaceous, 5-veined, glabrous. Upper lemma smooth, shiny, pale.

Distribution and ecology. – Endemic to Madagascar, restricted to high elevation and high soil moisture environments in the Andringitra massif, 2400–2700 m ( Fig. 8A ).

Notes. – Likely the most unusual of Madagascar’s grasses, P. cupressifolium does resemble a low stature conifer when forming monotypic stands on the plateau of Andringitra National Park. Leaf blades and leaf sheaths are reduced, while inflorescences are not readily visible as they are reduced to a single spikelet (or sometimes a group of up to three spikelets) at the culm apex.

The lectotype sheet has been chosen for its high quality material and an annotation in the author’s handwriting.

Additional material examined. – MADAGASCAR. Prov. Fianarantsoa: Andringitra , 27.XI.1924, Humbert 3888 ( G, K [ K000244696 , K000805462 ]; ibid. loco, VI.1965, Morat 1298 ( P [ P00224766 ]); Andringitra , à 100 m du pic, 22°11'42"S 46°53'31"E, 28.XI.2013, Nanjarisoa et al. 87 ( K, TAN); Andringitra , Peak Boby , 22°11'41"S 46°53'07"E, 25.XI.2009, Rakotonasolo et al. 1502 ( K [ K000664083 ]); Sendrisoa , 18.X.1956, Rakotovao 8452 ( P [ P02251441 ], TAN); ibid. loco, 12.I.1958, Rakotovao 9913 ( P [ P00224773 ]); Andringitra , below Imarivolanitra , 22°11'42"S 46°53'24"E, 12.XII.2013, Vorontsova et al. 1233 ( TAN); ibid. loco, 12.XII.2013, Vorontsova et al. 1237 ( TAN) .

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. 7. – Panicum cupressifolium A. Camus. A. Habit; B. Leaf; C. Flowering branch; D. Apex of flowering branch; E. Spikelet; F. Spikelet with glumes removed; G. Lower glume, dorsal view; H. Lower glume, ventral view; I. Upper glume, dorsal view; J. Upper glume, ventral view; K. Lower lemma, dorsal view; L. Lower lemma, ventral view; M. Upper floret with palea removed; N. Upper lemma, dorsal view; O. Upper lemma, ventral view; P. Upper palea, dorsal view; Q. Upper palea, ventral view; R. Immature caryopsis. [Nanjarisoa et al. 87, K] [Drawing: Lucy T. Smith]

Fig. 8. – Distribution maps. A. Panicum cupressifolium A. Camus (stars), P. danguyi A. Camus (triangles), P. dregeanum Nees (circles) and P. flacourtii A. Camus (squares); B. Panicum humbertii A. Camus (stars), P. humile Nees ex Steud. (triangles), P. ibitense A. Camus (circles) and P. inconspicuum Voronts. (squares).