Phycodrys phycodricola (E.Y.Dawson) J.M.Freese & C.E.Lane

Freese, Jillian M. & Lane, Christopher E., 2021, Reorganizing parasitic Delesseriaceae: taxonomic revision of Asterocolax, Phytotaxa 525 (2), pp. 124-136 : 133

Phycodrys phycodricola (E.Y.Dawson) J.M.Freese & C.E.Lane comb. nov.

DESCRIPTION: Thallus parasitic on Phycodrys setchellii Skottsberg. The protologue description can be found in Dawson (1945).

BASIONYM: Polycoryne phycodricola E.Y.Dawson (1945) Bulletin of the Southern California Academy of Sciences vol. 43, p. 107, Fig. 4 & 5 .

HETEROTYPIC SYNONYM: Asterocolax gardneri (Setch.) Feldmann & G.Feldmann

TYPE LOCALITY: Baja California, Mexico (coll. E. Y.Dawson, 1945)

ETYMOLOGY: The specific epithet resurrects the nomenclature used in the original description by Dawson (1944).

REFERENCES: Dawson 1945; Wagner 1954; Goff et al. 1997

DNA SEQUENCES: U59793.1 , Goff et al. 1997, Pigeon Point , Santa Cruz County, California, USA

REMARKS: This species was synonymized with Asterocolax gardneri by Wagner (1954). Wagner carried out a detailed study of the morphology of Asterocolax gardneri and found an unknown parasite on Phycodrys setchellii (San Francisco, CA) . The morphological similarity between this unknown parasite, the parasite morphology from Dawson’s (1945) description of Polycoryne phycodricola , and her work on A. gardneri (infecting Neinburgia andersoniana ) led Wagner to conclude that these parasites were all representatives of Asterocolax gardneri . Phylogenetic analyses show that Polycoryne phycodricola and Asterocolax gardneri (infecting Neinburgia andersoniana ) are unique species and the specific epithet “ phycodricola ” has been resurrected for the revised nomenclature of Polycoryne phycodricola .

Figures

FIGURES 2–4: Polyneura latissimicola FIGURE 2: Mature parasitic pustule of Polyneura latissimicola on its host Polyneura latissima. Thallus is yellow in color with numerous conical branches. Scale bar = 1 mm. FIGURE 3: 5 µm cross section of plastic embedded Polyneura latissimicola carposporophyte, stained in aniline blue. Cystocarps occur at the basal ends of Polyneura latissimicola branches. Released carpospores are spherical to ovoid in shape and average 10 µm in diameter. Scale bar = 100 µm. FIGURE 4: 5 µm cross section through Polyneura latissimicola and its host, Polyneura latissima stained in aniline blue. It is difficult to determine the spread of the infection throughout the host and differentiate between parasite and host cells. Much of the parasite thallus is composed of large cells many of which contain numerous floridean starch granules. The cortical cells of the parasite thallus are notably smaller than other cells composing the parasite structure or uninfected host cells and lack many of the starch granules found in the medullary cells. Scale bar = 100 µm.

FIGURES 5–7: Phycodrys denticulatus FIGURE 5: Mature parasitic pustule of Phycodrys denticulatus on its host Phycodrys fimbriata. Thallus is yellow in color with several round branches. Scale bar = 1 mm. FIGURE 6: 5 µm cross section of plastic embedded Phycodrys denticulatus stained in aniline blue. Tetraspores (*) occur along the branches of Phycodrys denticulatus and divide tetrahedrally or obliquely cruciate. Tetraspores average 40 x 60 µm. Scale bar = 100 µm. FIGURE 7: 5 µm cross section of Phycodrys denticulatus infecting Phycodrys fimbriata stained in aniline blue. Given the parasites immediate infection of host cells, it is near impossible to differentiate parasite cells from infected host cells. The medullary cells in the parasite thallus and the likely infected cells underlying the developing parasite thallus are conspicuously larger than uninfected host cells and filled with floridean starch granules. The cell walls of these extremely large medullary cells are also thicker than uninfected cells, a probable response to infection. Scale bar = 100 µm.