Phyllosiphon ari Procházková, Němcová & Neustupa, 2016

Procházková, Kateřina, Němcová, Yvonne & Neustupa, Jiří, 2016, Phyllosiphon ari sp. nov. (Watanabea clade, Trebouxiophyceae), a new parasitic species isolated from leaves of Arum italicum (Araceae), Phytotaxa 283 (2), pp. 143-154 : 150

Phyllosiphon ari Procházková, Němcová & Neustupa , sp. nov.

Branched filaments 20–45 μm in diameter, macroscopically visible as yellow-green spots 3–8 mm in diameter on leaves of the genus Arum . Ellipsoidal endospores solitary, uninucleated, 1.5–5.4 μm in diameter. Vegetative cells solitary, uninucleate. Cells spherical to ellipsoidal, 3.7–6.9 μm in diameter. Single parietal chloroplast containing starch, but no pyrenoid. Asexual reproduction via 2–6 spherical to ellipsoidal autospores, 5.1–9.6 μm in diameter. The species differs from the type species of the genus Phyllosiphon , Phyllosiphon arisari , by different host species of the parasitic stages, by presence of autospores and autosporangia with a characteristic ellipsoidal shape, the ornamented cell wall, as well as by differences in 18S rDNA and rbc L gene sequences.

Type locality:— CROATIA. Krk: the leaf of Arum italicum growing along a route near Njivice, 45°09′55.6″N 14°33′46.4″E, 8 m a.s.l., leaf sample collected by K. Procházková, 28 April 2015.

Holotype:— A leaf of Arum italicum with the source population of Phyllosiphon ari was deposited in the Herbarium collection of the Charles University in Prague ( PRC): holotype PRC 3715 and isotype PRC 3716. In addition, the strain CAUP C-H 8803, based on strain N 8 obtained from the holotype, has been cryopreserved in the CAUP Culture Collection (http://botany.natur.cuni.cz/algo/caup.html). The strain has also been deposited in CAUP as an active culture, CAUP H 8803.

Etymology:—The specific epithet is derived from the host plant genus Arum .

Habitat:—Branched filaments thrive in the leaf parenchyma of Arum , while the chlorelloid unicells thrive in subaerial biofilms, such as those on a tree bark.

Distribution:— Croatia; species was only found at the type locality.