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The Essex Records 1820 -2007.

Following the introductory paragraph to each taxon, the records are set out in columns. The first being the letter and alternative number (in brackets) code for the 100 x 100km square, followed by the 10 x 10km square number, arranged in conventional order from south to north, moving from west to east; the second column gives the 1 x 1km square or the 100 x 100m square Ordnance Survey grid reference if known; the third the vice county, and the final column the available details of the individual record. Approximate grid references for older records are suffixed by a ?

 

Chara vulgaris L. sensu lato

Several forms of this taxon have been given varietal names, such as vulgaris, longbracteata, papillata, crassicaulis and refracta. Having grown these in culture however, it is pretty obvious that they are not distinct genetic varieties but are simply ecomorphs, as the same plants change from one form to another as they grow. Quite what causes the switch between the forms is unclear. It does not seem to be correlated with daylength, but I suspect that the development of extended bracteoles and long spine cells is a response to predation, as water mites and juvenile Limnaea snails are particularly partial to the antheridia. Thus it is possible for a single plant to express both the papillata and the longibracteata morphology simultaneously.

I propose eventually therefore to reorganize this dataset under one heading with notes covering the type of expression exhibited by particular populations, and abandon the clearly illegitimate varietal names.

Chara vulgaris var. papillata Wallr. ex A. Braun

This supposed variety has been variously defined, but in essence it is said to possess long finger-like spine cells. Groves & Bullock-Webster (1922) and Moore (1986) agree in their being deciduous, but differ in whether they should be sticking out, or recurved and lying in the grooves. Guy Allen, on the other hand, says they can be both. The difficulty arises from the fact that long spine cells often occur on plants which also have very long bracteoles and adaxial bract cells. These have been conveniently regarded as `intermediates'. As explained in the paragraph above the various forms can interchange over time on the same plant and are apparently merely ecomorphic expressions.

 

TL(52)30 380,010 19 Waltham Abbey, Cornmill Measows, Lea Valley Park, shallow ditches. August 2010. Peter Tymkoir Det: Nick Stuart.  
         

TQ(51)48

???????

18

Between West Ham and the Thames, in the marshes and ditches, c.1849. Edward Forster.

Natural History Museum Herbarium. Atlas Specimen No.1381.

 

41 ,81?

18

Beckton District Park, East Ham, 6 January. 1985. Coll: Paul Kirby, Det:: K.J.Adams. (approaching this variety).

 
         

TL(52)40

479,086

19

Harlow Common, the 'new' concrete margined pond, choking the shallows, with long spine cells, abundantly fertile, good material of the formerly recognised var. refracta. 20 October 1985. Coll: & det: K.J.Adams.

 
         

TL(52) 41

490,183

19

Thorley Flood Pound, flooded marshy adjacent to R. Stort, with Ranunuculus aquatilis, Berula erecta and Juncus inflexus. Substrate calcareous. 18 Oct 1992. Det:: J.A.Bryant.

 

TQ(51) 58

513,853

18

Dagenham, The Chase Nature Reserve, Easterbrook End Country Park, abundant in two shallow pools just north of the railway. Bracteoles and supine. 20 June 1999. K.J.Adams et EFC.

 
         

TL(52) 50

584,036

18

High Ongar, small pond, excavated in 1985 to replace old pond destroyed by widening of the A414. Opposite drive to Chevers Hall. Extensive, bright fresh-green patches arising among extensive rafts of dying C. vulgaris var. longibracteata, fruiting, spine cells very long and numerous. 23 Nov. 1986. Coll: & det: K.J.Adams

 
         

TL(52) 54

500,432

19

Great Chesterford, flooded gravel pit by M11, frequent in the shallows, heavily encrusted, antheridia and oogonia present.. 18 July 1990. Tim Pyner.

 

TQ(51)67

65 ,75

18

Tilbury Energy & Environment Centre. October 1989. Coll: Janet Millington, det: Nicholas F Stewart.

 
 

648/9,756

18

Tilbury, massive quantities of material choking the whole length of the drain immediately north of the east-west segment of Fort Road, just north of Tilbury Fort. Spine cells variable on same plants from vestigial to very long and curved-supine to long straight and spreading, but all arising from sunken primary rows. Bract cells and bracteoles varying from very short to very long, again on the same plants. Plenty of immature male and female organs. Oospores brown. 8 September 1999. K.J.Adams

 

TL(52) 62

????????

19

Felsted, 1952. Coll: E.A.Robinson. Confirmed: Guy O.Allen.

B.S.B.I.. Proceedings. 1. p.69. 1954.

         

TL(52) 71

718,104

19

Broomfield, flooded gravel pit near Hill Farm, south of the boating lake, abundant with antheridia and oogonia. 18 July 1990. Tim Pyner.

 
         

TQ(51)98

911,853&         911,854&          911,856&             906,852

18

Southchurch, Thorpe Hall Golf Course, in small, (normally) winter wet ponds, abundant, male and female organs present, heavily encrusted. 21 July 1998. Tim Pyner.

Southend Central Museum Herbarium (STD).