Carex cespitosa, Carex elata e Carex nigra (fo. cespitosa) - Chiave per l'identificazione

[Umberto Ferrando]

Tratta da T.J. James; P. Jiménez-Mejías; M.S. Porter - The occurrence in Britain of Carex cespitosa, a Eurasian sedge rare in western Europe - New Journal of Botany, Volume 2, Number 1, June 2012 , pp. 20-25(6)

PARTIAL KEY – FOR THE IDENTIFICATION OF CAREX CESPITOSA, C. ELATA AND C. NIGRA (TUSSOCK FORM)

1a- Stigmas 2......................................................................2

1b- Stigmas 3.....................................................................other Carex species

2a- Spikes dissimilar in appearance, sessile or
pedunculate..................................................................3

2b- Spikes one, or spikes similar in appearance,
sessile.........................................................................other Carex species

3a- Rhizomes far-creeping......................................................other Carex sect. Phacocystis species (and C. saxatilis)

3b- Rhizomes short, densely caespitose and tussock
forming.........................................................................4

4a- Rhizomes very short, erect, forming dense tussocks, lowest bract
much shorter than inflorescence, leaves with stomata confined to
lower surface...................................................................5

4b- Rhizomes creeping upward away from anaerobic water-table and thus
accumulating peat and forming substantial tussocks; lowest bract +/-
equaling inflorescence; leaves with stomata mainly on upper
surface...........................................................................tussock form of C. nigra

5a- Height to 120cm; leaves glaucous; basal sheaths keeled, pale
yellow-brown, splitting to form fibrillae; male spikes 1-3; female
spikes to 70mm; utricles nerved, to 4·0mm................................C. elata

5b- Height to 80cm; leaves bright yellowish-green; basal sheaths
round-backed, purple-brown; male spike 1; female spikes to 30mm;
utricles nerveless, to 2·5mm..................................................C. cespitosa

Può risultare utile soprattutto per chi si trova alle prese con la forma cespitosa di Carex nigra (L.) Reichard (Carex goodenowii Gay) o per confermare/disconfermare vecchie segnalazioni di Carex cespitosa L.

Ciao
Umberto

[arslan1]

nice post