CHARACTERIZATION OF SCHIZOSERIS CONDENSATA,SCHIZOSERIDEAE TRIB. NOV. (DELESSERIACEAE,RHODOPHYTA)1

The Myriogramme group of Kylin contains two distinct clusters of genera that merit recognition at the tribal level. We previously established the tribe Myriogrammeae, and in this paper we erect the Schizoserideae based on a study of the type species of Schizoseris, S. laciniata (=S. condensata), from the southern hemisphere. The Schizoserideae is characterized by 1) marginal and diffuse intercalary meristems; 2) nuclei initially arranged in a plate in the median plane in meristematic and mature cells; 3) chloroplasts one to few, lobed or dissected; 4) microscopic veins absent; 5) procarps scattered, formed singly on either side of the blade with cover cells absent and consisting of a one- to two-celled lateral sterile group, a one- to two-celled basal sterile group, and a four-celled carpogonial branch in which the trichogyne passes beneath the lateral sterile group and emerges anterior to it; 6) auxiliary cell diploidized by a connecting cell cut off posteriolaterally from the fertilized carpogonium; 7) gonimoblast initial cut off laterally from one side of the auxiliary cell and giving rise to unilaterally branched gonimoblast filaments bearing carposporangia in branched chains; 8) gonimoblast fusion cell highly branched, candelabra-like, incorporating all but the basalmost cells of the carposporangial chains and radiating through the central cells in the floor of the cystocarp; 9) spermatangial and tetrasporangial sori formed from surface cells in both monostromatic and polystromatic portions on both sides of the blade; and 10) tetrasporangia formed primarily from cortical rather than from central cells. The Schizoserideae presently includes Schizoseris Kylin, Neuroglossum Kützing, Abroteia J. Agardh, and Polycoryne Skottsberg in Kylin and Skottsberg.     

Drachiella liaoii sp. nov., a new member of the Schizoserideae (Delesseriaceae,Rhodophyta) from Taiwan and the Philippines

A new member of Delesseriaceae (Ceramiales, Rhodophyta) is described from Southern Taiwan and the Philippines. On the basis of comparative vegetative and reproductive morphology, and phylogenetic analysis inferred from nuclear-encoded large-subunit ribosomal DNA sequences (LSU rDNA), we conclude that it belongs in the genus Drachiella, tribe Schizoserideae, subfamily Phycodryoideae. The new taxon shares with other Drachiella species the absence of macro- and microscopic veins; diffuse growth by marginal and intercalary meristematic cells; a polystromatic, lobed thallus; abundance of rhizoidal marginal proliferations used for attachment; convoluted plastids in surface cells; abundant secondary pit connections among adjacent vegetative cells; large intercellular spaces between surface cells; procarps confined to the upper side of the thallus, circular in outline, consisting of a supporting cell bearing a strongly curved carpogonial branch and two sterile groups that remain undivided; vertical division of gonimoblast initial from auxiliary cell, and unilateral, monopodial branching of gonimoblasts; and mature cystocarps with a massive candelabrum-like fusion cell of fused gonimoblasts bearing carposporangia in branched chains. It is distinguished from the other members of the genus by thalli that consist of extensive tangled mats of prostrate and overlapping decumbent blades, procarps confined to the upper side of the thallus, and the lack of basal stalks or stipes. Whereas the Schizoserideae is predominantly a Southern Ocean tribe, one of the tribe's four genera, Drachiella, was known only from the eastern Atlantic and Mediterranean. We herein report the first record of the genus for the Indo-Pacific Ocean, and describe Drachiella liaoii, sp. nov., as a fourth species in the genus.