Richard L. Moe

Climate Change and the Future of California's Endemic Flora

The flora of California, a global biodiversity hotspot, includes 2387 endemic plant taxa. With anticipated climate change, we project that up to 66% will experience >80% reductions in range size within a century. These results are comparable with other studies of fewer species or just samples of a regions endemics. Projected reductions depend on the magnitude of future emissions and on the ability of species to disperse from their current locations. Californias varied terrain could cause species to move in very different directions, breaking up present-day floras. However, our projections also identify regions where species undergoing severe range reductions may persist. Protecting these potential future refugia and facilitating species dispersal will be essential to maintain biodiversity in the face of climate change.

MORPHOLOGY AND TAXONOMY OF HIMANTOTHALLUS (INCLUDING PHAEOGLOSSUM AND PHYLLOGIGAS), AN ANTARCTIC MEMBER OF THE DESMARESTIALES (PHAEOPHYCEAE)1

The sporophyte of Himantothallus develops according to a closed pattern in which the number and position of the blades is determined by the location of trichothallic meristems in a filamentous germling. Expansion of the miniature juvenile to the massive adult thallus is accomplished by diffuse secondary growth and involves a change from filamentous rhizoids to a hapteroid holdfast, flattening of the stipe, and enormous increases in length, breadth, and thickness of both stipe and blade. The axis usually bears 1–8 lateral blades, often paired, and terminates in a flattened stub. Phaeoglossum is interpreted as a growth form of Himantothallus in which a terminal blade develops to the exclusion of lateral blades, the latter being represented by a single spine. Phyllogigas clearly falls within the morphological spectrum of Himantothallus, the lack of twisting being related to physical factors in the environment.

Antarctic Marine Flora: Uniquely Devoid of Kelps

The discovery of embryonic stages of the common large Antarctic brown seaweed Himantothallus has led to the conclusion that this plant, hitherto assigned equivocally to the Laminariales (kelps), is a member of the Desmarestiales. Moreover, field study of a large sample of Himantothallus and two other enigmatic brown algae, Phyllogigas and Phaeoglossum, has led to the merger of these three genera with the recognition of a single species, Himantothallus grandifolius. The correct placement of these kelp-like algae underscores the uniqueness of the Antarctic marine flora as the only cold-water flora without kelps.

Morphological and taxonomic studies on Antarctic Ceramiaceae (Rhodophyceae). I. Antarcticothamnion polysporum gen. et sp. nov.

Antarcticothamnion polysporum gen. et sp. nov. (Rhodophyceae: Ceramiaceae) is described from the South Shetland Is. and the Antarctic Peninsula. It differs from all previously described Ceramiaceae in vegetative structure: an indeterminate apex, which divides by alternating oblique septa, produces simple alternate-distichous determinate branches, while indeterminate branches are initiated on main axes in a verticillate arrangement. Reproductive structures are borne on modified indeterminate branch systems. Sporangia are polyhedrally divided. Spermatangia are formed in loose heads. Procarps are borne near the apex, but not always on the subapical cell, of a fertile branch. Two auxiliary cells may participate in the formation of a carposporophyte. A fusion cell is lacking and most cells of the gonimoblast develop into carposporangia, which are binucleate. The suite of morphological characters exhibited by Antarcticothamnion sets this genus sufficiently apart from all previously described Ceramiaceae to warr...

Morphological and taxonomic studies on Antarctic Ceramiaceae (Rhodophyceae). II. Pterothamnion antarcticum (Kylin) comb. nov. (Antithamnion antarcticum Kylin)

Reproductive structures in Antithamnion antarcticum Kylin (Rhodophyceae: Ceramiaceae) are described for the first time. Tetrasporangia are cruciately divided and sessile, replacing first- or second-order branchlets of major and minor whorl-branches. Spermatangia are cut off in whorls by spermatangial mother cells, which in turn are produced in whorls by distal cells of ordinary first- or second-order branchlets of major and minor whorl-branches. Procarps are produced by the basal cell of non-reduced major whorl-branches at least 10 cells below the apical cell of an indeterminate axis, 1 or 2 per axis. Gonimolobe initials apparently arise directly from the auxiliary cell. Carposporophyte development does not suppress further growth of the axis, but no additional procarps are formed. Carposporophytes are naked. Vegetatively, A. antarcticum is characterized by a sinusoidally curving apex that cuts off groups of first-formed laterals in an alternating secund pattern, always bending away from the side that is ...

Morphological and taxonomic studies on Antarctic ceramiaceae (Rhodophyceae). III: Georgiella and Plumariopsis (Tribe Ptiloteae)

Knowledge of the structure and reproduction of Georgiella confluens (Reinsch) Kylin, the type of its genus, is amplified and clarified. The apical cell is not overtopped by lateral branches. Indeterminate axes are formed mainly from first-formed branches. Cortication develops from a single initial cut off by the basal cell of branches and branchlets. Spermatangia are borne in extensive sori. The supporting cell of a procarp is equivalent to a transverse pericentral cell and bears a horizontally oriented carpogonial branch. A second auxiliary cell may be cut off by the transverse pericentral cell on the opposite side of the axis. Tetrasporangia are tetrahedrally divided. A study of the type of Plumariopsis eatonii (Dickie) De Toni, the type of its genus, leads to the conclusion that this species does not occur in Antarctica, despite previous reports. The apical cell is overtopped by lateral branches. Indeterminate axes are formed solely from second-formed branches. Cortication develops from three initials ...

Ultrastructural study of the brown alga Petroderma maculiforme (phaeophyceae) in the free-living state and in lichen symbiosis with the intertidal marine fungus Verrucaria tavaresiae (Ascomycotina)

A comparative TEM study was carried out on the phaeophyte Petroderma maculiforme, collected from San Francisco Bay both as free-living thalli and as phycobiont of the lichen fungus Verrucaria tavaresiae. The free-living alga usually had thicker cell walls and substantially greater reserves in storage bodies than the lichenized form. Cell division patterns were altered in symbiosis, and formation of zoosporangia was not observed on the lichenized filaments. Both free-living and lichenized Petroderma showed an abundance of densely osmiophilic deposits associated with vesicles, which were interpreted as physodes; Golgi and ER appeared to be involved in the elaboration of their contents. Plastids of both free-living and lichenized forms possessed a large pyrenoid deeply penetrated by tubular invaginations of the plastidial membranes. This pyrenoid was often enfolded by lobes of the plastid as previously reported, but also commonly occurred as a broad-based protrusion from the surface of the plastid. Smaller, exserted pyrenoids with a very narrow base and no tubular invaginations were sometimes also observed on plastids of the lichenized alga, but were not seen on those of free-living thalli. The significance of this variation in pyrenoid type was not clear. The considerable variation in pyrenoid position and form in P. maculiforme suggests that the protruding, enfolded, and stellate pyrenoid positions known in brown algae are not profoundly different from each other developmentally.

MARIPELTA ATLANTICA SP. NOV. (RHODOPHYTA, RHODYMENIALES) A NEW DEEP-WATER ALGA FROM FLORIDA1

A red alga with a cylindrical stipe bearing a single deciduous blade was collected in deep water off the east coast of Florida. It is described as Maripelta atlantica sp. nov., differing from M. rotata (Dawson) Dawson (the type of the genus, from deep water off California and Baja California) chiefly by having an annular tetrasporangial nemathecium on the lower surface of the blade rather than scattered nemathecia on the upper surface. Both species are vegetatively and reproductively distinct from M. thivyae Dawson, which is transferred to Halichrysis. New information is given regarding the reproduction and distribution of M. rotata.

Lipid Composition and Metabolic Activities of Benthic Near-Shore Microbial Communities of Arthur Harbor, Antarctic Peninsula: Comparisons with McMurdo Sound*

SummaryBenthic microbial communities of the Arthur Harbor area were described by analysis of their cell membrane phospholipid ester-linked fatty acids (PELFA) and metabolic rates. Analysis revealed a biomass averaging 6 nM (phospholipid) or 3.5×108 cells per gram dry weight (gdw) of sediment for the four sites. Only slight biomass differences were detected between the four peninsula sites. All Arthur Harbor sites were determined to have a biomass similar to the lowest amount reported for a previously described McMurdo Sound site at New Harbor. Community structure based on signature phospholipids indicated only slight differences between the four peninsula sites with greater relative amounts of diatom marker lipids at a deeper site. Bacterial biomarker lipids were also determined in relatively equal proportions for the four Arthur Harbor sites with only one site indicating a somewhat decreased proportion. Metabolic rates of sodium [14C]-acetate and methyl [3H]-thymidine incorporation into lipid and bacterial DNA respectively also indicated only slight relative differences in microbial communities of Arthur Harbor study sites. Lipid metabolism (14C-acetate) ranged between 6 and 12 (x104) DPM/g/h for the four sites with 8 being the average. Bacterial (excluding sulfate-reducing bacteria (SRB)) cell divisions per g per h indicated increased rates at a deeper site with 14×105, compared to the average (5×105) for the three remaining sites. Average estimated total bacterial (excluding SRBs) community turnover was on the order of 0.6%/h for the four sites. Metabolic rate comparisons of Arthur Harbor with those of previously determined McMurdo Sound indicated a somewhat increased lipid metabolism and an order of magnitude greater bacterial cell division rate at Arthur Harbor.

The Index Nominum Algarum

Summary Silva, P. C. & Moe, R. L.: The Index Nominum Algarum. - Taxon 48: 351-353. 1999. ISSN 0040-0262. The Index Nominum Algarum (ING) is an ongoing project with the goal of producing and maintaining an index of scientific names of algae, both living and fossil, at all ranks. Initiated by Silva in 1949, it now comprises about 180,000 entries. Although it is currently in the form of a card file housed in the Herbarium of the University of California at Berkeley, it is being converted into a database that will be searchable on-line. Meanwhile, the cards, only about 10 % of which are backed by an electronic file, have been archived as digital images on compact discs. An important by-product of the INA is the Bibliographia Phycologica Universalis (BPU), which now comprises about 65,000 references. Both the INA and the BPU have been made available to the taxonomic community continuously since their inception.