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tasmanian mosses - mniaceae
pohlia species
The family is represented in Tasmania by 2 genera comprising of 6 species. We identified to species level by the 'vermicular' nature of the gemmae from Shaw's paper cited below.
What struck us as interesting about this species is the profusion of gemmae found growing in the leaf axils, this particular form being known as '(vermicular) bulbils'. Gemmae are asexual propagules capable of developing into clonal replicas of the parent and complement sexual reproduction through spore production. However they are delicate and more likely to establish close to the parent plants. Spores are much hardier and likely to colonize further.
1. Plants growing on road bank
 2. upper leaves |
 3. bulbils on leaf |
 4. single bulbil |
 5. leaf cells |
Pix 2: shows quantities of gemmae lodged in the leaf axils of the
moss; this was from our first collection where the bulbils dispersed
upon wetting
Pix 3: a single leaf excised from the stem exposing the adhering
bulbils; these are from a second collection, presumably less mature
than those in previous pix and remained attached despite wetting
Pix 4: a single bulbil
Pix 5: cell shape is often useful for identification
Capsules are often a good diagnostic feature for identification but Shaw quotes J. Spence having noted that all Tasmanian specimens examined were sterile. In which case all multiplication would be exclusively by gemmae.
References
Shaw, A.J., 'A revision of the Moss Genus Pohlia Hedw. (Mniaceae) in
Australia', Systematic Botany (2006), 31(2):
pp.247-257
Web
- Glime, J., 'Ecophysiology of
Development: Brood Bodies' Chapter 5-7 of Bryophyte Ecology
- Guerra, J., 'Pohlia Section (Mielichhoferiaceae, Bryophyta) with
axillary bulbils in the Iberian Peninsula', 2007 has detailed images
of other Pohlia bulbils
- Shaw, J. & Fife, A.J., 'Pohlia australis
sp. nov. (Musci) from New Zealand with notes on some other austral
Pohlias' (originally published in New Zealand Journal of Botany,
1985, Vol 23: 183-186) is available from the Smithsonian Digital Repository
Page URL: http://www.bluetier.org/Moss/mniaceae.htm