Carex otrubae Podp.

False Fox-sedge

Spisy Prir. Fak. Masarykovy Univ. 12: 15 (1922) APNI

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Naturalised

Rhizome short; shoots densely tufted. Culms erect, sharply trigonous, smooth below, scabrous above, 30–60(–100) cm long, c. 1.5–2 mm diam. Leaves shorter or longer than culms, to 60 cm long, blade 4–8(–10) mm diam; sheath white with green veins, the leaf sheath back transversely-septate, leaf sheath front not transversely-rugose, becoming brown, soon decaying; ligule tubular, acute, 5–10 mm long. Inflorescence narrow panicle, becoming dense when in fruit, erect, (1.5–)3–5.5 cm long,  c. 1.5 cm diam., compound, spikes numerous; lowest involucral bract shorter than or longer than inflorescence. Spikes sessile, mostly contiguous or lowermost group separated, erect to spreading at maturity; spikes all or most male above and female below, 0.8–1.4 cm long; male glumes 3.5–4 mm, oblanceolate-elliptic, pale orange-brown with green midrib, apex acute; female glumes 4–5 mm long, ovate, pale red or orange-brown with green midrib, apex acuminate-aristate; utricles 4.5–4.7 mm long, 1.5–1.8 mm diam., ovoid, plano-convex, shiny, strongly nerved, often scabrous on shoulders, green, at maturity red-brown, adaxial epidermis smooth or barely minutely elongate-papillate, the epidermal cells elongate; beak 1–1.5 mm long, bifid, not split at back, apex unwinged, margins scabrous; style 2-fid. Nut oblong-obovoid, biconvex, flat, yellow-brown,  2.3–2.6 mm long.

*MuF. Africa (Algeria, Morocco, Tunisia), Eurasia. Naturalised in New Zealand. Native to most of Europe. In Australia currently known only from Victoria. First collected in 1995, from the Cohuna region, with several additional collections from Horfield between 2003 and 2004. Currently appears to be confined to irrigated pasture, and paddocks. Jermy et al. (2007) comment that it is a species of heavy soils.

Very close to Carex vulpina (not naturalised in Australia). Carex otrubae and C. vulpina have long been considered difficult to separate due to their morphological similarity, and intraspecific variation in both species. Several morphological characters have been used to distinguish between the two species, but these can be variable. One of the more reliable characters has been the shape of the adaxial epidermal cells of the utricles, but even here there is some overlap between the two species. The adaxial surface of the utricles in the Victorian plants is more or less smooth or barely minutely papillate, and the epidermal cells are elongate. In contrast the utricles in C. vulpina are obviously minutely papillate, with more or less isodiametric cells. Porley (1999) suggested that internal leaf anatomy characters provide an unequivocal way of distinguishing between the two species. However, subsequent studies have shown this to be inconclusive (Smith & Ashton 2006). Smith & Ashton (2006) have suggested that stomatal shape may be of use to differentiate the two species, but more work is required (Jermy et al 2006).

Created by: Val Stajsic, 2015-07-03
Updated by: Val Stajsic, 2018-06-20
 
References

Jermy, A.C.; Simpson, D.A.; Foley, M.J.Y.; & Porter, M.S. (2007). Sedges of the British Isles, Botanical Society of the British Isles.

Porley, R.D. (1999). Separation of Carex vulpina L. and Carex otrubae Podp. (Cyperaceae) using transverse leaf sections, Watsonia 22: 431-432.

Smith, C. & Ashton, P.A. (2006). Distinction between the sedges Carex vulpina L. and C. otrubae Podp. and the potential for identification of hybrids , Watsonia 26: 15-25.

Distribution map
life Life
kingdom Plantae
phylum Tracheophyta
superorder Lilianae
order Poales
family Cyperaceae
genus Carex
Higher taxa

Victoria

Source: AVH (2014). Australia's Virtual Herbarium, Council of Heads of Australasian Herbaria, <http://avh.chah.org.au>. Find Carex otrubae in AVH ; Victorian Biodiversity Atlas, © The State of Victoria, Department of Environment and Primary Industries (published Dec. 2014) Find Carex otrubae in Victorian Biodiversity Atlas
  Bioregion Occurrence status Establishment means
Murray Fans present introduced

State distribution

Distribution map
State
Victoria