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Poaceae in the Robinson Crusoe (=Juan Fernandez) Islands number 53 species in 32 genera, of which 9% of the species are endemic, 9% indigenous, and 81% adventitious. The endemic taxa (and their conservation status) are: Agrostis masafuerana (rare), Chusquea fernandeziana (not endangered), Megalachne berteroana (not endangered), M. masafuerana (not endangered), and Podophorus bromoides (extinct). Megalachne and Podophorus are endemic genera. Comparisons with Poaceae in the Bonin and Volcano Islands, Canary Islands, Galapagos Islands, and Hawaiian Islands show different levels of endemism: number of endemic taxa, respectively, 5, 10, 12, 40; percent specific endemism, 8, 6, 21, 19. No endemic genera occur. Anthoxanthum odoratum, Avena barbata and Hordeum murinum are noxious weeds in the Robinson Crusoe Islands. Many adventives are shared among floras of the archipelagos, with the highest ties of Robinson Crusoe being to the Canaries (53% of total Poaceae known in Juan Fernandez) and the Hawaiian Is...

Morphological and ITS sequence divergence were assessed between the two presently recognized taxa of the endemic genusCuminia (Lamiaceae), on Masatierra of the Juan Fernandez Islands. Morphological studies were based on leaf morphology of 51 individuals. Individuals ofC. fernandezia have narrow and lanceolate leaves with cuneate to acute bases and apices, whereas individuals ofC. eriantha have broadly ovate leaves with rounded bases and acute to obtuse apices. The two taxa can also be distinguished by the presence of pubescence.Cuminia eriantha has hairs on the leaves, young stems, floral peduncles, calyx, and corolla. Alternatively,C. fernandezia is glabrous except for tuft hairs on the nodes, and hairs on calyx teeth and corolla tubes. The ITS 1 and 2 regions of the five plants ofCuminia sequenced are a total of 451 bp long. All plants have identical ITS-1 but pubescent and glabrous plants are consistently different in ITS-2 sequence, revealing 1.3% total sequence divergence between the species. Both morphological and molecular data support the taxonomic recognition of two taxa, and the small but consistent differences appear to justify species status for the two entities. The pubescent populations representC. eriantha and the glabrous ones areC. fernandezia. It is hypothesized that the species diverged from a common ancestral immigrant to the islands, when Masatierra was much larger and more ecologically diverse than it now is. The two taxa seem to maintain their identities with no evidence of hybridization, even though they often grow in close proximity to one other on the island. Each population consists only of glabrous or pubescent plants, with no mixed population detected.

Nassauvia coronipappa Arroyo & Marticorena, from Cerro Donoso in eastern Chilean Patagonia, is described and illustrated. It is distinguished by trifid inner involucral bracts and persistent, brief, laciniate-dentate, crown-like pappus incompletely surrounding summit of the achene. The distinctive pappus may be related to selection, in harsh alpine habitats, against dispersal away from nurse sites.Nassauvia coronipappa belongs to subgenusNassauvia. It is seen as a relict member of an independent line of evolution, whose closest affinities are with sectionNassauvia of that subgenus.