Poa secunda secunda J. Presl. Reliq. Haenk. 1(4-5): 271 1830.

Soreng, Robert J. & Peterson, Paul M., 2012, Revision of Poa L. (Poaceae, Pooideae, Poeae, Poinae) in Mexico: new records, re-evaluation of P. ruprechtii, and two new species, P. palmeri and P. wendtii, PhytoKeys 15, pp. 1-104 : 58-60

19. Poa secunda secunda J. Presl. Reliq. Haenk. 1(4-5): 271 1830. Fig. 20 A-G

Type:

Chile, Cordilleris Chilensibus, 1790, T.Haenke (holotype: PR!; isotypes: B, BAA-2691! fragm. ex B, GH! fragm., LE!, LE-TRIN-2625.01a!, MO-209304!, US-88729! fragm. ex PR). Poa orcuttiana Vasey, W. Amer. Sci. 3: 165-166. 1887. Type: USA, California, near San Diego, 26 May 1884, C.R.Orcutt 1070 (holotype: US-556833!). Atropis scabrella Thurb., Bot. California 2: 310-311. 1880.). Poa scabrella (Thurb.) Benth. ex Vasey, Grass. U.S. 42. 1883. Panicularia scabrella (Thurb.) Kuntze, Revis. Gen. Pl. 2: 783. 1891. Puccinellia scabrella (Thurb.) Ponert, Feddes Repert. 84(9-10): 740. 1974. Type: USA, California, Oakland, H.N.Bolander (holotype: NY! ex herb. Nash ex herb. Thurber; isotype: US-556836! fragm. ex herb. Nash ex herb. Thurber & photo).

Description.

Hermaphroditic. Perennials; tufted, tufts dense, narrow to medium girth, tiny to medium height (2 to over 20 cm tall), usually narrow based, green or bluish-grey-green; tillers intravaginal (each subtended by a single elongated, 2-keeled, longitudinally split prophyll), without cataphyllous shoots, sterile shoots more numerous than flowering shoots. Culms (10-)15-80(-100) cm tall, erect or bases slightly decumbent, slender to stout, leaves mostly basal, terete or weakly compressed; nodes terete, 0-2 exerted. Leaf sheaths terete, scabrous, glabrous; butt sheaths papery, smooth, glabrous; flag leaf sheaths (7-)10-20(-25) cm long, margins fused 10-25% the length, (0.95-)1.5-7(-15) × long as its blade; collars smooth or scabrous, glabrous; ligules of culm leaves 2-6(-10) mm long, of sterile tillers mostly 2-6 mm long, abaxially smooth or scabrous, apices truncate to acuminate, sterile shoot ligules similar to those of the culm leaves, blades of cauline leaves 0.4-3 mm wide, flat, folded, thin, soft, and soon withering, lax. smooth, or scabrous mainly over veins, glabrous, narrowly prow-tipped; blades gradually reduced distally or the middle blades, flag leaf blades 0.8-10(-17) cm long; sterile shoot blades similar in form to cauline blades. Panicles 2-15(-20) cm long, erect, contracted at maturity, narrowly lanceoloid to ovoid, usually congested or moderately congested (except in flowering), with 10 to over 100 spikelets; rachis usually with 1-3 branches per node; primary branches erect or ascending, infrequently widely spreading at maturity. terete to weakly angled, on and between angles usually sparsely to densely scabrous; lateral pedicels 1/6-1/3 the spikelet length, moderately to somewhat densely scabrous, prickles fairly coarse; longest branches (0.5-)1-8(-10) cm, with (1-)2-20(-60+) spikelets in distal 2/3-1/2. Spikelets, (4-)5-8 mm long, (3.8-)4-5 × long as wide, usually narrowly lanceolate, sub- terete to weakly laterally compressed, not bulbiferous, drab, green or strongly anthocyanic, sometimes glaucous; florets (2-)3-5(-10), hermaphroditic; rachilla internodes terete or slightly dorsaventrally compressed, usually 1-2 mm long, smooth or muriculate to scabrous or hirtellous; glumes lanceolate to broadly lanceolate, slightly unequal, keels indistinct, keel and upper sides scabrous, apex acute to acuminate, lower glumes (2.5-)3-3.5 mm long, 3-veined; upper glumes 3.5-4 mm long, 3-veined; calluses glabrous, or with a crown of hairs around the base of the lemma, hairs 0.1-0.5(-2) mm long, crisp or slightly sinuous; lemmas 3.5-6 mm long, lanceolate to narrowly lanceolate or slightly oblanceolate, usually weakly keeled, lemma keels and marginal veins short villous to crisply puberulent or softly puberulent over proximal 2/3, between veins usually at least sparsely crisply puberulent or softly puberulent, hairs usually less than 0.5 mm long; intermediate veins obscure, margins strongly inrolled below, broadly scarious above, apices obtuse to broadly acute, blunt or sometimes pointed; paleas scabrous along the length or medially often short villous to softly puberulent over the keels, intercostal region often softly puberulent. Flowers chasmogamous; lodicules 0.55-0.8 mm long, broadly lanceolate, with a well developed lateral lobe nearly equaling the main lobe; anthers 1.5-3 mm long. Caryopses 2.2 mm long, fusiform in side-view, round on back, olivaceous, weakly sulcate, hilum 0.25 mm long, oval, grain free from the palea. 2 n = 42, 44, 56, 63, ca. 68, 70, ca. 72, ca. 74, ca. 78, ca. 80, 82, ca. 83, 84, 85, 86, ca. 87, ca. 88, ca. 90, ca. 91, 93, ca. 94, ca. 98, ca. 99.

Distribution.

This species is widespread in North America: Canada (all Provinces except New Brunswick, Nova Scotia, Nunavut, PEI); USA (Alaska, and all western states); Mexico (Baja California); South America (Argentina and Chile).

Ecology.

The species occurs in coastal chaparral communities to coniferous forests at over 1000 m elevation in Baja California. It is high polyploid ( Soreng 1991a) and predominantly apomictic over much of its geographic range ( Kellogg 1987). Flowering March to May in B.C.

Specimens examined.

Mexico. Baja California: Municipio Ensenada, Arroyo de Agua Caliente, al E de Ojos Negros, 1 May 1981, R. Guzmán-M. 1341 (MEXU). Camino entre rancho Mike’s y San Jose Mellin, R. Guzmán-M. 1414 (MEXU). Tia Juana Valley, 6 Apr 1882, C.G.Pringle 37 (LL, US, US). Todos Santos Bay, Apr 1882, F.E.Fish 28 (US); ditto, 30 (US); ditto, 33 (US). Canutillas Mts., 1884, C.R.Orcutt 1148 (US). Guadalupe Canyon, 10 Apr 1885, C.R.Orcutt 1269b (US). Carisito, 8 Apr 1885, C.R.Orcutt s.n. (US). near Vallecito, 5 Apr 1886, C.R.Orcutt 1440 (MO, US); South slope 8 miles from Rosario on road to El Marmol, 4 Mar 1930, I.L.Wiggins 4338 (LL, US). 11 mi E of Tecate on road to Mexicali, 3600 ft [1095 m], 23 Dec 1971, A.A.Beetle M-1403 (TAES); Humorosa, 4270 ft [m], 15 Apr 1973, A.A.Beetle M-2710 (TAES). 5 mi E of Humorosa, 3000 ft [910 m], 15 Apr 1973, A.A.Beetle M-2699 (TAES). Just east of Rancho Cuevas, 5 mi S of Rosarito, 32°17'N, 117°01'W, 60 m, 30 Mar 1975, R.Moran 21704 (TAES). Sierra Blanca, east of main summit, 32°03.5'N, 116°30.5'W, 1175 m, 16 May 1976, R.Moran 23237 (TAES). Sierra Juárez, 12 May 1997, A.Carrillo-S. 96 (MEXU). Laguna Hansen, 1 May 1981, R. Guzmán-M. 1351 (MEXU). Sierra Juárez, 5 km W of La Rumorosa, 32°33'N, 116°06'W, 1325m, 15 May 1977, R.Moran 24100 (TAES). Rancho El Potrereo, 40 km al SW de el Observatorio de Sierra San Pedro Mártir, 1050 m, P.Tenorio-L. 13218 & C.Romero-deT. (MEXU). Sierra San Pedro Mártir, arroyo 3 km e of El Soccoro, 30°58.4'N, 115°37.8'W, 1450 m, 8 May 1978, R.Moran 25702 (TAES).

Discussion.

Hitchcock (1913, 1935) accepted Poa scabrella with Poa orcuttiana as a synonym. Espejo Serna et al. (2000) accepted Poa orcuttiana and Poa scabrella ; and Dávila Aranda et al. (2006) accepted Poa scabrella as synonym of Poa secunda subsp. secunda but Poa orcuttiana as a synonym of Poa secunda subsp. juncifolia. In our opinion Poa orcuttiana and Poa scabrella should be placed as synonyms of Poa secunda subsp. secunda ( Soreng 1991a, 2007). There is some question regarding the geographic origin of the type of Poa secunda . It could be from California, and it seems unlikely that Haenke would have missed it there, whereas it is uncommon, at least today, in the southern Andes. There is no doubt in our minds that the North and South American plants are Poa secunda subsp. secunda (DNA sequences from South American specimens align with those from North America; Gillespie pers. comm.). If Poa scabrella formswere to be recognized, it would be best to treat them as a varietyof Poa secunda subsp. secunda, but this is not proposed here because it would only cause confusion selecting the correct name at the varietal rank among the many synonyms for this taxon. For this species Gould and Moran (1981) cite Isla Guadalupe as a location, possibly based on R.Moran 13816 (TAES) but this specimen is Koeleria pyramidata Lam. [incl. Koeleria cristata s. auct., Koeleria macrantha (Ledeb.) Schult.].

Figures

Figure 20. A-G Poa secunda J. Presl. subsp. secunda A habit B sheath, ligule, blade C inflorescence D spikelet E floret F palea G anthers H-L Poa strictiramea Hitchc. H basal tuft I sheath, ligule, blade, ventral view J inflorescence K spikelet L floret. Drawings A-L from Soreng (2007) H, J, L originally drawn from Swallen 1110 as Poa involuta in Hitchcock (1935).