Poa annua L., Sp. Pl. 68. 1753 subsp. annua

Ortega-Olivencia, Ana & Devesa, Juan A., 2018, Updated checklist of Poa in the Iberian Peninsula and Balearic Islands, PhytoKeys 103, pp. 27-60 : 27

12. Poa annua L., Sp. Pl. 68. 1753 subsp. annua

Poa annua var. viridis Lej. & Courtois, Comp. Fl. Belg. 1: 80. 1828. [Type: "not expressly indicated"].

Poa ovalis Tineo, Pl. Rar. Sicil., fasc. 2: 21. 1846. [Type: "In pascuis montosis, apricis, palustribus. Cotrano al Gurgo lo Drago"].

Poa annua var. aquatica Asch., Fl. Brandenburg 1: 844. 1864. [Type: "Provinz Brandenburg S. Altd. Sumpf hinter dem Pfarrgarten"].

Poa annua var. typica Beck, Fl. Nieder-Österreich: 84. 1890, nom, inval.

Poa annua var. ovalis (Tineo) Trab. in Batt. & Trab., Fl. Algérie (Monocot.) 2: 206. 1895.

Poa annua f. Poa plicata prostrata Sennen, Pl. Espagne n. 605. 1908, nom. nud., in sched. (MA 11165), p.p., syn. nov.

Poa annua var. lanuginosa Sennen, Diagn. Nouv. sér. 1933: 209, n. 8980. 1936. [Type: "Hab.- Maroc: Melilla à Rostrogordo. Leg. Hno. Mauricio"] (lectotype designated here: "1933.-Plantes d’Espagne. -F. Sennen / N° 8980 / Poa annua L. / var. lanuginosa Sennen / Maroc: Melilla, à Rostrogordo / 2-III Leg. Hno. MAURICIO" (label printed): specimen upper on the left, BC 119353; isolectotype: MA 11155).

Poa annua f. lanuginosa Sennen & Mauricio, Cat. Fl. Rif Orient.: 132. 1934, nom. nud., syn. nov.

Poa annua var. pilantha Ronniger, Verh. Deutsch. Bot. Ges. Wien 88-89: 97. 1941. [Type: "not expressly indicated", but the material was collected on the island of Zante, Ionian Islands, Greece].

P. annua subsp. pilantha (Ronniger) H. Scholz, Ber. Deutsch. Bot. Gesell. 81: 19. 1968.

Ochlopoa annua (L.) H. Scholz, Ber. Inst. Lanschafts- Pflanzenökologie Univ. Hohenheim, Beih. 16: 58. 2003.

Ochlopoa annua subsp. pilantha (Ronninger) H. Scholz & Valdés, Willdenowia 36: 661. 2006.

Poa annua annua Ill. Ruiz (1991: 27, lam. I), Soreng and Peterson (2012: 14, fig. 2A-E), Devesa (1987: 261).

Type.

" Habitat in Europa ad vias" (lectotype designated by Soreng 2000, pg. 254: right-hand plant, Herb. LINN No. 87.17!) .

Flowering.

All year.

Ecology.

Pastures and grasslands along roads, fallow fields, gardens, margins of watercourses and more or less nitrified soils of all types; edaphically indifferent; 0-2100 m a.s.l.

Distribution.

Cosmopolitan, although apparently of Mediterranean origin. Throughout the Iberian Peninsula and Balearic Islands. And. Port: AAl Ag BA BAl BB BL DL E Mi (R) TM. Spa.: A Al Av B Ba Bi Bu C Ca Cc Co CR Cs Cu Ge Gr Gu H Hu J L Le Lo Lu M Ma Mu Na O (Or) P PM [Mll, Mn] Po S Sa Se Sg So SS T Te To V Va Vi Z Za. For a representative list of studied materials, see Suppl. material 1.

Notes.

Plants are found in the territory covered by Flora Iberica that have hairy lemmas, at least towards the internerval basal zone, with this indumentum being more perceptible in apical flowers of the spikelet. This characteristic is usually accompanied by a very dense silky indumentum in the veins. In other cases, the spikelet has lemmas with a glabrous internerval surface, usually accompanied by a lower density of indumentum in the nerves, with sometimes even the medium ones being glabrous or glabrescent. The first variation corresponds to Poa annua var. lanuginosa Sennen (Diagn. Nouv. sér. 1933: 209, n. 8980. 1936), a name that prevails over the name P. annua var. pilantha Ronninger (Verh. Deutsch. Bot. Ges. Wien 88-89: 97. 1941). When Scholz in Ber. Deutsch. Bot. Gesell. 81: 19 (1968) raised Ronninger’s taxon to the subspecies category, he stated that the distribution of this subspecies was Mediterranean (e.g. Greece, Italy, Spain and Morocco) and extra-Mediterranean for the type subspecies. Although plants of Mediterranean environments in the Iberian Peninsula tend to have hairier lemmas, we have also found specimens assignable to var. Poa annua and, conversely, we have observed plants with hairy lemmas in typically Eurosiberian areas (e.g. Lugo, Minho, Oviedo and Santander) and even Macaronesia (e.g. Madeira).

In certain populations, some spikelets are completely sterile and reduced to a set of whitish or hyaline membranes. Although infrequent, plants with loosely antrorse-scabrid inflorescence branches have been detected, perhaps as a result of hybridisation with other species (e.g. MA 420475, MA 449625).

DNA sequence data support the hypothesis that P. annua , a tetraploid species, has arisen by hybridisation-and subsequent polyploidisation-between two Eurasian diploid species, the annual P. infirma Kunth and the rhizomatous perennial P. supina Schrad. ( Soreng et al. 2010; Mao and Huff 2012), as suggested by Nannfeldt (1937).