Early Land Plants Today (ELPT): How many liverwort species are there?

Abstract

Estimates of extant liverwort species range from 4,500 to 9,000, with estimates in the past decade converging on 5,000 to 6,000. Potential problems and pitfalls of deriving species estimates are addressed, including binomial accumulation, the impact of synonymy, taxonomic inflation, the impact of unrevised species-rich genera, species concepts and cryptic species. We present a revised mean estimate of 7,500 for the number of liverwort species based on estimating rates of synonymy in a sample of recently monographed and revised taxa. This estimate does not include infraspecific names and may underestimate global diversity as a result. We also present a databased estimate of about 8,500 species derived from the Early Land Plants Today data set. We argue higher estimates are supported by: 1) the number of published species has not reached a plateau and new species continue to be discovered; 2) not all regions have been thoroughly explored and with equal intensity, with survey effort being historically biased toward northern temperate regions; 3) synonymy rates are not uniform across taxonomic groups; 4) novel discovery of species outpaces new species derived from elevation in rank (taxonomic inflation); and 5) species numbers are not necessarily distorted by large unrevised genera. A standardized global worldwide liverwort checklist with strong community participation coupled with the critical need for ongoing monographs and revisions, will aid in arriving at a clearer estimates of liverwort diversity. We promote and encourage interest in the topic using an evidence-based approach and quantitative data.

Dehydration protection provided by a maternal cuticle improves offspring fitness in the moss Funaria hygrometrica

“…Liverworts elevate their fully differentiated sporangia on an ephemeral seta, via cell elongation, and spore dispersal occurs as a single event over a relatively short period of time (Crum, 2001). The ability of mosses to build a permanent seta that enables spore dispersal over an extended time period represents a distinct evolutionary advantage, which may have contributed to the greater number of moss species compared with liverworts [9000-13 000 (Magill, 2010) to 5000 -6000 (von Konrat et al, 2010), respectively].…”

Identification of volatile compounds from three species of Cyathodium (Marchantiophyta: Cyathodiaceae) and Leiosporoceros dussii(Anthocerotophyta: Leiosporocerotaceae) from Panama, and C. foetidissimum from Costa Rica.

“…There are, ca. 22,000-25,000 species of bryophytes in three lineages (Magill, 2010;Villarreal et al, 2010;von Konrat et al, 2010), the liverworts (Marchantiophyta), the hornworts (Anthocerotophyta) and the mosses (Bryophyta). They are considered the closest modern relatives of the ancestors of the first terrestrial plants (Renzaglia et al, 2007).…”

Notes on Early Land Plants Today. 37. Towards a stable, informative classification of the Lepidoziaceae (Marchantiophyta)

“…Although estimates of total species number for liverworts are notoriously variable (von Konrat et al 2010), the number of accepted species is c. 860 (ELPT database), perhaps as much as 9-10% of the total liverwort species diversity. Taxonomic diversity is highest in cool, wet areas of post-gondwanan land fragments, but the family is cosmopolitan in distribution.…”