Poa perconcinna J. R. Edm., Bot. J. Linn. Soc.
Year: 2026
Type: article
Abstract: 8.Poa perconcinnaJ. R. Edm., Bot. J. Linn. Soc. 76 (4): 330. 1978. ≡ Poa concinna Gaudin, Agrost. Helv. 196. 1811 (nom. Illeg. hom., non. R. Br., 1810). ≡ Poa bulbosa var. concinna Posp., Fl. Oesterr. Küstenl. 1: 97. 1881. (nom. nov. for P. concinna Gaudin). ≡ Poa bulbosa subsp. concinna (Posp.) Hayek, Repert. Spec. Nov. Regni Veg. 30 (3): 260. 1933. Type protologue [Switzerland] Hab. In arenosis Valesiae inferioris, et praecipue Seduni. Type specimen. “ Schleicher exs. of Cent. II. No. 12. Poa molinerii Balb. ” In aridis circa Branson (lectotype, designated by Soreng and P. Descombes, in Soreng and Tasenkevich 2025, p. 514 and fig. 3: G [G 01100147]; isolectotype: G, LAU [LAU 31572 / A: G 3169 B], W [W 18890246843, image!; plant on left]; W [W 19240005263, image!]). Description. Perennials; hermaphroditic; tufted, without rhizomes or stolons, tufts dense, small, compact, green or greyish-green; tillers bulbous at the base, intravaginal; prophyll keels retrorsely scabrous; bulbs subglobose to short pyriform, erect or somewhat divergent, basal-most sheaths thickened, indurate at the base for 3–4) mm of the length, mostly 0.5–1 cm long, prominently several veined, the outermost, papery, not persisting as a tunic, slightly lustrous; Culms 5–18 (- 30) cm, erect or geniculately ascending, slender, well exerted, terete, internodes smooth, smooth or lightly scabrous, glabrous, 1–2 (– 3) nodes exerted. Leaves mostly basal, culm leaves 1 to 2; leaf sheaths of culms weakly compressed, strongly imbricated at base; flag-leaf sheaths 1.5–5 cm long, margins fused 22–27 % the length, smooth, glabrous, infrequently scabrous near the collar; collars smooth or sometimes scaberulous, glabrous; ligules 1.5–3 (– 4) mm long, hyaline to slightly white apices acute to narrowly acute, entire or shallowly dentate, or lacerate, of sterile shoots 0.8–2 mm long, broadly decurrent, whitish; blades 0.3–1 cm long, 0.5–1 mm wide, subequal or those of the sterile shoots, gradually reduced in length upward, mostly folded, thin, soft, soon withering, surfaces glabrous, abaxially scabrous, margins scabrous, apices narrowly prow-tipped, scabrous, sterile shoot blades 0.5–3 (– 6) cm long, 0.5–1 (– 1.5) cm wide, soon withering. Panicles 1–2.5 (– 3.5) cm long, narrowly elliptical, contracted or briefly spreading, compact, crowded with 15–55 spikelets, well exerted at maturity, axis with 1–2 (– 3) branches at lower nodes; primary branches 0.5–1 cm, with 3–9 spikelets in the distal 1 / 3–1 / 2, erect to ascending, lower ones sometimes spreading, terete to weakly angled, moderately strict, moderately to densely scabrous; pedicels mostly less than 1 / 5 the spikelet in length, sparsely to moderately scabrous. Spikelets 3–5 (– 6.5) mm long, broadly ovate, compact, laterally compressed, greenish; bulbifery absent; florets (2 –) 4–7 (– 10), widely divergent; rachilla internodes mostly 0.2–0.4 mm long, smooth or sparsely scaberulous, glabrous, hidden; glumes 1.5–2 (– 3) mm long, shorter than their adjacent lemmas, ovate to broadly ovate, unequal to subequal, matt, distinctly keeled, keel distinctly arched, keel and sometimes margins distally scabrous; apices obtuse to acute; lower glume 2 / 3 to equally as wide as upper glume, 3 - veined; upper glume 3 - veined, broadly ovate; callus glabrous or webbed, web sparse, hairs to 2 mm long; lemmas (2 –) 2.2–2.6 (– 2.8) mm, broadly ovate, green or pale green, matt, distinctly keeled, keels and marginal veins ciliate to villous with hairs in a single file, between veins glabrous, intermediate veins faint to obscure or absent, margins inrolled below, distally scarious-hyaline, edges scaberulous, apices obtuse to acute, pointed; palea keels scabrous, between keels smooth, glabrous. Flowers bisexual; anthers (0.8 –) 1.1–1.3 mm long. Caryopsis 1.2 mm long, fusiform, broadly sulcate, light brown, hard, adherent to the palea; hilum 0.2 mm long, elliptical. 2 n = 14. Clade code: unknown. Distribution and ecology. The Alps of Austria (?), France, Italy, and Switzerland. Semiarid slopes, montane steppe meadows in crevices, sand, and thin soils, to the low alpine zone, from (500 –) 900–2,500 m. Conservation status. None. G has many herbarium specimens and observations. Comments. A species of low and compact stature, generally barely exceeding 18 cm in height, with small, dense tufts, sheaths swollen at the base, and very thin and narrow basal blades. The panicles are oval or pyramidal, sometimes quite dense, with compact spikelets having up to 10 florets. This xerothermophilous species is found in dry grasslands and rocky or sandy sites in hilly and mountainous regions and can also reach alpine regions up to 2,500 m altitude. It occurs in Switzerland, commonly in the canton of Valais. It is also known in France in the Alpes-Maritimes, Hautes-Alpes, and Savoie. Poa perconcinna was named by Edmondson (1978) to replace the illegitimate name P. concinna Gaudin (1811), that binomial having been used previously for another taxon by Robet Brown in 1810. As for P. carniolica (Mutel) Hladnik ex Bech. and P. concinna var. carniolica Mutel, according to Edmondson the name appears to correspond to a form of P. bulbosa and should in no case be taken as a synonym of P. perconcinna. Poa perconcinna does closely resemble P. bulbosa; however, as mentioned above, the short and soon-withering character of the basal blades, associated with their extreme thinness (generally 0.3–0.4 mm wide when the blade is folded), makes it easy to recognize this species. Other characters, including the length of the lemmas and anthers, support its separation from P. bulbosa. Note also that in P. perconcinna the spikelets are more densely imbricated and divergent from the rachilla than in P. bulbosa. The taxon has been counted as 2 n = 14, whereas reports of that number in P. bulbosa are generally doubted (Soreng and Tasenkevich 2025 and others). Guinochet’s (1942) diploid count for P. bulbosa from the Maritime Alps of France likely belongs to P. perconcinna (Soreng and Tasenkevich 2025). Portal (2005) separated the taxa as follows: - Poa perconcinna: lemma ≤ 2.8 mm long, tomentum absent or sparse; generally, anther ≤ 1.2 mm long. [to which we would add florets crowded on short rachilla internodes and divergent]; Poa bulbosa: generally, lemma ≥ 3 mm long, tomentum usually abundant, rarely absent; generally, anther ≥ 1.3 mm long. Reports from further east in Euro + Med PlantBase (accessed June 2026) have not been verified by RJS (Bosnia-Herzegovina, Bulgaria, Croatia, Montenegro, Italy (beyond the Alps), and Serbia). According to Scholz (1986), plants from Greece are referable to P. bulbosa subsp. pseudoconcinna (Schur) Asch. & Graebn. Portal (2005) treated the latter as P. bulbosa var. bulbosa, and keyed P. perconcinna apart apart as follows: lemmas ≤ 2.8 mm long, callus hairs absent or sparse, anthers usually ≤ 1.2 mm long, vs. lemmas ≥ 3 mm long, callus hairs fairly abundant, rarely absent, and anthers usually ≥ 1.3 mm long. Portal (2005) cited the Type as “ Habitat in arenosis Valesicae inferioris, praecipua Seduni ” J. Gaudin, 1811 [removing the “ et ”] but did not indicate an herbarium. Representative specimens. Switzerland. (Soreng 9500, 9501).
Language: English
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7225780692
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