Numerical analysis of morphology of natural hybrids between Carex hostiana and the members of Carex flava agg. (Cyperaceae)

Abstract

Uni‐variate and multi‐variate statistical methods, based on data taken from dried specimens, were used to determine the morphological variance of Carex hostiana 3 Carex flava agg. hybrids and to establish their parents among members of the C. flava complex. The following hybrids were found: C. demissa 3 hostiana [C. 3 fulva], C. hostiana 3 lepidocarpa [C. ×leutzii] and C. flava 3 hostiana [C. 3 xanthocarpa]. The least variable traits, namely beak length, utricle length, ratio of beak length to the overall utricle length, female spike width, and width of the lowest bract, proved to be the most useful in delimiting the hybrids. Carex flava 3 hostiana specimens usually have long utricles and beaks, wide male and female spikes, as well as wide bracts and leaf blades. Carex hostiana 3 lepidocarpa specimens are characterized by relatively short beaks (with low ratio of beak length to the overall utricle length) and narrow bracts. Common features of C. demissa 3 hostiana specimens, on the other hand, are male spikes with long peduncles, usually longly parted female spikes and a long beak compared to the overall utricle length.

Carex flava agg. (section Ceratocystis, Cyperaceae) in Poland: taxonomy, morphological variation, and soil conditions

“…Within the section Ceratocystis, some hybrids between C. hostiana and members of the C. flava group have been found (Kiffe 2001;Koopman 2010;Więcław & Koopman 2013). The hybrids were completely sterile (see Davies 1955;Schmid 1982), more or less similar to C. hostiana or morphologically intermediate between parental forms.…”

“…Besides, specimens of C. demissa × C. hostiana are very similar to C. hostiana × C. lepidocarpa, and according to Wallace et al (1975) they can be distinguished only on the basis of spike size (spikes are narrower and slightly shorter than in hybrid of C. demissa). A study conducted by Więcław & Koopman (2013) shows that specimens of C. ×fulva have shorter utricles, male spikes on longer peduncles, and narrower female spikes, usually more distant from one another than in specimens of C. ×leutzii. Another significant difference is also the ratio of beak length to total utricle length, which is higher for C. ×fulva than for C. ×leutzii.…”

“…In herbarium material some specimens were completely sterile and filled the phenetic space between C. hostiana and members of the C. flava group. One group of OTUs was intermediate between C. hostiana and C. lepidocarpa, while another group of OTUs was intermediate between C. hostiana and C. demissa, so the specimens were classified as hybrids: C. ×leutzii and C. ×fulva, respectively (Więcław & Koopman 2013). Contrasting views can be found in literature on nomenclature of the hybrids and their putative parents of the C. flava group.…”

“…Utricle length declines in the following order: C. ×xanthocarpa (C. flava as a parent), C. ×leutzii (C. lepidocarpa as a parent), and C. ×fulva (C. demissa as a parent). Ratio of beak length to utricle length is high for C. ×fulva (like for C. demissa) and low for C. ×leutzii (like for C. lepidocarpa) (Więcław & Koopman 2013).…”

“…In total, identification of over 3500 herbarium specimens was verified and 1500 herbarium specimens were measured. Additionally, herbarium specimens of C. hostiana were verified, as it also belongs to the section Ceratocystis and often forms hybrids with taxa of the C. flava complex (Kiffe 2001;Więcław & Koopman 2013). C. hostiana, as the only species of this section, has welldeveloped, short rhizomes and narrowly cylindrical, remote, female spikes usually on peduncles, and dark brown glumes (Chater 1980;Crins & Ball 1987).…”