Trichanthecium chionachne (Mez) Zuloaga

Zuloaga, Fernando Omar, Aliscioni, Sandra, Delfini, Carolina & Salariato, Diego Leonel, 2024, Old World species of Trichanthecium (Poaceae: Panicoideae: Paniceae) including a new species from the Democratic Republic of Congo, Phytotaxa 646 (3), pp. 230-264 : 241-243

4. Trichanthecium chionachne (Mez) Zuloaga , comb. nov.

Panicum chionachne Mez (1921: 185) .

Lectotype (here designated):— TANZANIA. Rungwe District, Kymbila, 1600 m, 15 May 1912, A. Stolz 1270 ( M [ 0103866 ] image!, isolectotypes BR [0000008760661!], G [00022446!], JE [00006127] image!, K [000282487!], L [1294047] image!, S –G-[4483] image!, U![0257877] image, US [00148350!] [fragment ex M], US [00731052!], W [19160007804!], WAG [0001524] image!) . Fig. 5

Annual or short lived, not tufted perennial; culms slender 35–90 cm long, decumbent and branching at the lower and middle nodes; internodes cylindrical, 3–12 cm long, hollow, glabrous; nodes compressed, pale, glabrous. Sheaths striate, 3–10(–15) cm long, usually shorter than the internodes, sparsely hispid to glabrous. Ligule membranous, laciniate at the apex, 0.6–0.7 mm long, hyaline, with long hairs beneath at the base of the blade. Blades lanceolate, 5–10(–16) × 0.5–1 cm, rounded toward the base and then narrowed into a short and pilose pseudopetiole, pseudopetiole pilose, acuminate, glabrous or pilose, the margins scabrous. Inflorescence a terminal, lax and exserted panicle, 10–20 × 6–20 cm; peduncle cylindrical, 15–25 cm long, hispid to glabrous, pulvini hispid or glabrous; first-order branches alternate, divergent, axis of the branches glabrous, spikelets solitary on flexuous, claviform pedicels 1–5 mm long. Spikelets ovoid, 2.1–2.5 × 0.8–0.9 mm, acuminate, greenish and tinged with purple; lower glume lanceolate, 2–2.2 mm long, 4/5 to as long as the spikelet, 3-nerved, acute, membranous, glabrous; upper glume ovate, 5(–7)-nerved, membranous, acute or acuminate, glabrous; lower lemma glumiform, 5-nerved, membranous, acute, glabrous; lower palea narrowly elliptic-ovate, 1.4–1.6(–2) × 0.4–0.6 mm, hyaline, glabrous; lower flower staminate or neuter. Upper anthecium ovoid, 1.5–1.9 × 0.7–0.9 mm, indurate, pale, glabrous, smooth, shiny; upper lemma 5-nerved. Caryopsis narrowly ovoid, 1.2 × 0.6 mm; hilum punctiform, embryo 1/3 the length of the caryopsis.

Distribution and habitat: —This species is commonly found in east tropical Africa( Burundi, Rwanda, Democratic Republic of Congo, Sudan, Kenya, Tanzania, Uganda. Malawi, and Zambia) in shaded forest habitats, from 1000–3000 m elevation.

Typification: —The holotype of Panicum chionachne at B was destroyed. An isotype at M is here designated as lectotype; it was identified by Mez and consists of a full specimen that agrees with the protologue.

Notes: —This species is morphologically related, and perhaps conspecific, with Trichanthecium hochstetteri , the latter differing by having spikelets usually sparsely pubescent, oblong in outline.

Brown (1977) reported that this is a non-Kranz species.

Representative specimens examined: — BURUNDI. Siguvyaye (Bururi), 1 June 1979, Ndabaneze 638 ( BR). DEMOCRATIC REPUBLIC OF CONGO. Nioka , 10 March 1956, Froment 10 ( BR). MALAWI. Zamba Plateau , 23 November 1949, Wiehe N/363 ( P, US) ; Mlanje Mountain, Likabula valley , Wiehe N/358 ( US) ; banks of Mulungusi stream, Zomba, Wiehe N/611 ( US). TANZANIA. Mpanda District : 12 km N of Uzondo Camp, 5 May 2008, Bidgood et al. 6667 ( K, P) ; Uzondo Plateau , 17 April 2006, Bidgood et al. 5581 ( K, MO, P) ; Mufindi, Kigogo river valley, Renvoize & Abdallah 1903 ( K, MO) ; Nyassa-Hochland, Station Kyimbila , Stolz 1374 ( JE). UGANDA. Kigezi, Kachwekano Farm , Purseglove 3476 ( K) ; Mubende , Thomas 4123 ( K, US). ZAMBIA. Muchinga. Mpika District: Mutinondo Wilderness Area , western end of Airstrip , 9 May 1916, Bidgood et al. 8727 ( K, P) .

Figures

FIGURE 5. Trichanthecium chionachne. A. Habit. B. Ligular region. C. Detail of a branch of the inflorescence. D. Spikelet, lateral view. E. Lower glume. F. Lower palea with anthers. G. Upper anthecium, dorsal view. H. Upper anthecium, ventral view. I. Upper palea, lodicules and caryopsis. J. Caryopsis, hilum view. (Wiehe N/363 US).