EVENTS

Members Reports and Photos

 

PRAEGER CENTRE, national botanic gardens,  2 may 2015

LEADERS: DeCLAN DOOGUE & Pat lenihan

Early-flowering Plants including Grasses and Dandelions  (Declan Doogue)
Due to the lateness of the season, grasses in flower were scarce but members brought in a range of early flowering plants including Crucifers, Fumitories, Spurges and Speedwells.

Declan gave us a short talk on Dandelions especially on members of the Palustria Section which includes Taraxacum amarellum and T. webbi and talked about the cuation of plants of this genus. The latter species appears to have a rather restricted distribution in Ireland - fens and lakeshores?
 
Identification of Hymenophyllum species (Pat Lenihan)

Hymenophyllum wilsonii and Hymenohyllum tunbrigense 
Hymenophyllum
means “membranous leaf" and refers to the very thin translucent tissue of the fronds, which gives rise to the common name Filmy Ferns. The leaves of these ferns are deeply divided with small distinct teeth, and are generally only one cell thick. They lack stomata, which makes them vulnerable to desiccation. Consequently, they are found only in very humid sites. Two species in the genus Hymenophyllum occur in Ireland: H. wilsonii (Wilson’s filmy fern) and H. tunbrigense (Tunbridge Filmy Fern).

Hymenophyllum wilsonii 
This
 is a small (2 –12 cm long), native, fragile, evergreen fern that looks like a moss or liverwort and is easily overlooked. It forms large dense colonies from creeping black rhizomes on rocks and trees in moist, humid woods, and in sheltered mountain crevices and open rock faces. In Ireland it is found mainly in the  south-west, west and north-west, often on high ground.

Its leaves are deep green, very thin and translucent, and their tips are slightly recurved giving their upper surface a convex appearance above.  It is characterized by indusia that have untoothed tips* and dark veins reaching to the leaf-margin. The fronds arch out distinctly at an angle and appear upright. Spores are ripe in June – July.

Hymenophyllum tunbrigense
This fern is very similar in appearance to H. wilsonii and occurs on boulders and tree trunks in moist woods, and in crevices in mountainous and lowland areas.

It can be distinguished from H. wilsonii by its indusia which have toothed tips*, veins that do not reach the leaf-margin, and a more flattened appearance. Its pale bluish-green leaves are somewhat lighter in colour than those in H. wilsonii. In Ireland, it is also less common than the latter, being occasional in the south-west and rare elsewhere.

             Summary

H. wilsonii  H. tunbrigense 
Indusium entire  Indusium irregularly toothed
Leaves arch away from substrate (upright)  Leaves hand over substrate (flat)
Veins reach leaf margin Veins do not reach leaf margin

Leaves darker colour

Leaves lighter in colour
More frequent on higher ground More frequent on lower ground
Locally frequent
SW distribution, rare elsewhere

" See Figs 7a and 7b in An Irish Flora (Webb) 2012, page 10.    

Pat Lenihan


Recent Publications
British Moths (Chris Manley 2nd Edition).  This is a photographic guide to both micro and macro moths.

Moth Traps and Trapping (David Nash & Pat Kearney)
Pat and David gave an introduction to the use of moth traps and mentioned some books and websites which are very helpful in the identification of moths. The Field Club has now owns a number of traps for member use and it is envisage that recorders will network with each other in their use and assist one another in identifications. It is hoped to introduce a project for next season once there is a greater familiarity with the ID of species. The Wexford Field Club meeting will have a moth ID session on the Monday morning.

Field guide to moths of Great Britain and Ireland (2nd eddition) by Paul Waring and Martin Townsend. Illustrated by Richard Lewington. [Macros only.]

Field guide to micro moths of Great Britain and Ireland by Phil Sterling and Mark Parsons. Illustrated by Richard Lewington.  [Micros only.]

British Moths by Chris Manley (2nd edition). A Photographic Guide [Both micros and macros.]

   

Grasses of the British Isles              Sesleria caerulea                          

    

                                    Taraxacum Section Palustria      Dandelions of Great Britain and Ireland

 

               Barbarea vulgaris                                     Coronopus didymus                    Thlaspi arvense

     

Lamiastrum ssp. argentatum         Senecio squalidus                  Matricaria discoidea  

    

                                Diplotaxis muralis              Euphorbia helioscopia             Hyacinthoides non-scripta x H. hispanica

    

Hymenophyllum tunbrigense

       

Hymenophyllum wilsonii

    

                  Fumaria officinalis                    F. bastardii            Pentaglottis sempervirens           

   

       British Moths           a Skinner Moth Trap             Field Guide to Moths

     

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