1.) CHAROPHYTES - Stonewort's - Pages

1.) CHAROPHYTES - Stonewort's

Species account:

CHAROPHYTA Charophytes

CHARACEAE Stoneworts

Stoneworts are a fascinating group of plants. They hold a hugely important role in the makeup of aquatic ecosystems and their presence is always something to be celebrated. Their ability to flourish in a wide range of situations but also sensitivity to invisible changes (such as pollution) and fluctuating presence can be useful in indicating the health and quality of our freshwater bodies. One year a healthy pond or ditch may become swamped by a stonewort only for it to seamlessly vanish the next; before reappearing many years later, once favourable conditions have been restored (usually after disturbance or clearance work). Their elusive nature brings fascination to any botanist lucky enough to stumble upon one when scanning the water's edge. Most modern floras choose not to include them because they are not vascular plants but in fact structurally complex green algae. However, many older volumes do cover this group and there seems to have been a slight resurgence of interest in them over recent years. It is hoped that their inclusion here will spark a greater interest in the study of this poorly recorded and much undervalued family of plants.

CHARA L.

Chara vulgaris L. (Common Stonewort) / Wetland Uncommon By far the commonest and least habitat-specific stonewort in the region; inhabiting ponds, lakes, ditches, rhynes and slow-moving rivers; ranging from highly alkaline to mildly acidic and even withstands brackish waters. But disappears if nutrient levels get too high (as is often the case when systems are exposed to agricultural runoff, pollution and where dogs frequent). Most concentrated in the rhyne systems around Weston in Gordano, Nailsea and Yatton; very scattered elsewhere but likely under-recorded. It was significantly more common in the past. The disappearance of ponds and more recently; chemical pollution and increase in nutrient and toxin levels (such as Nitrogen, Phosphorus & PFAS - 'forever chemicals') is to blame. It is a regular coloniser of newly dug or temporary water bodies. The following varieties aren't well recorded and only the species is mapped.
var. vulgaris (Common Stonewort) / Wetland Uncommon The common variety, with the same range as the species.
var. crassicaulis (Schleich. ex A.Braun) Kütz. (Thick-stemmed Stonewort?) Wetland Extinct? Only once recorded from Nailsea on the 10th Sept 1904 by J. W. White. (not mentioned in his flora, 1912) and its inclusion here is on the basis of a determination made of a preserved specimen located in the Natural History Museum. It prefers deep, highly alkaline water and should be searched for in the rhynes from Nailsea to Weston-in-Gordano.
var. longibracteata (Kütz.) J. Groves et Bullock-Webster (Long-bracted Stonewort?) Wetland Very Rare Recorded only recently from rhynes at Weston-in-Gordano where it is locally plentiful but a number of historical records exist, including: "Pond between Bedminster and Whitchurch; W. B. Waterfall." (White, 1912 & Murray, 1896); Nailsea, 1904, J. W. White (not in his flora); Bitton, 1914 in a Mill Pond, I. M. Roper (also Riddelsdell, 1948); and from Inglestone Common, 1993 - during clearance work by Plantlife of the same pond known for the nationally rare Adder's-tongue Spearwort (Ranunculus ophioglossifolius). Though rare it is likely under-recorded.
var. papillata Wallroth ex A. Braun (Papillate Stonewort?) Wetland Extinct? Once widespread and locally abundant in ponds and ditches but hasn't been seen for almost 90 years. Historic records include: "Ditch between Portbury and Portishead, 1889," J. W. White (White, 1912 & Murray, 1896); "Abundant in peat ditches of the Walton Valley; named by Messrs. H. and J. Groves;" "Tickenham Moor;" "Ponds in Prior Park, Bath (White, 1912 & Marshall, 1914); "Pool in ground that had been worked for strontia at the back of Goose-green Farm, N. of Yate, 1910." (White, 1912 & Riddelsdell, 1948); and additionally from a pond between Engine Common and Wickwar, near Ladden Brook, 1917 by C.I. Sandwith; and last seen at Blagdon in 1937 by H. S. Thompson. It is likely still present in the Gordano Valley and the area around Tickenham and Weston-in-Gordano. And perhaps also the area North of Yate and around Blagdon.
Chara contraria A. Braun ex Kütz. var. contraria (Opposite Stonewort) Wetland Very rare First discovered near Dunkerton in June 1910 by C. Bucknall and J. W. White where it was found in "stagnant water in a portion of the abandoned coal canal where it is crossed by the Radstock road" (White, 1912). Later found at Clapton Moor, Clapton-in-Gordano in 1922 by C.I. Sandwith and there again pre-1990 by an unknown recorder. Repeated searches have been made by D. Hawkins but it has not been re-found. More recently (2015) present at both Blagdon and Chew Valley lake. It might well still occur in the abandoned canal near Dunkerton but the site has become very shaded by trees - though it is certainly worth looking for in other suitable waterbodies nearby. A resurvey is much needed.
Chara hispida L. (Bristly Stonewort) Wetland Very Rare Rare but very locally plentiful in rhynes between Walton-in-Gordano and Weston-in-Gordano where it has been known since the 19th century. Elsewhere it was recorded at Bathampton in 1956 by J. P. Brennan and close by from a brook near Batheaston in 2000 by Landmark Environmental Consultants. Older records include: "Kenn Moor, 1904," J. W. White; "Between Yatton and Clevedon;" "Portbury; W. E. Green" and "In the canal; Fl. Bathon. Suppl." (White, 1912, Murray, 1896 & Marshall, 1914). It should be searched for at these older sites. Chara aspera (Rough Stonewort) was recorded in the past but the records are mistakes for C. hispida (as mentioned by white in his flora). Still, its existence in our region is not impossible.
Chara aculeolata Kütz. (Hedgehog Stonewort) Wetland Very rare Occurs only in the Gordano Valley, where it is rare and in small quantity. First discovered in a "Pond near the railway by Nailsea Station, 1880 by A. Leipner and E. H. Read," and later found in "Peat ditches on Walton Moor" where it's been known since 1903 (White, 1912 & Marshall, 1914) - then under the name C. polyacantha.
Chara globularis Thuill. (Fragile Stonewort) Wetland Rare The second most common stonewort in the region, after C. vulgaris. Scattered and rare but locally frequent in ponds, lakes and rhynes in the Gordano Valley, Nailsea Moor and Blagdon Lake; very sporadic elsewhere. Was once more widely distributed; however it isn't overly fussy and is able to colonise new locations. Occasionally it turns up in garden centres (attached to aquatic plants) - where it no doubt spreads to newly built ponds. This was demonstrated in the case of a find made at Severn Beach in 2023 by D. Hawkins and D. Peters - in one of two very poorly made ponds - created as part of an 'off-set' to the newly implemented sea wall defences. Three varieties are mentioned in local historical sources (then as C. fragilis) as occurring in our area: var. capillacea, var. delicatula and var. hedwigii. Today the first and last are seen as meaningless taxa not worthy of recognition but var. delicatula now refers to the following species.
Chara virgata Kütz. var. virgata (Delicate Stonewort) Wetland Very rare Occasional in the Gordano Valley and in quarry pools around Yate and Wickwar where it can form dense stands and intermingles with C. hispida in the former. First recorded in the region in N. Somerset at Kewstoke in 1850 by Edward Chitty and much later at Nailsea by H.S.T in 1921. All other historic records amplify today's known distribution in the north of our territory (as extracted from White, 1912 & Riddelsell, 1948): "Yate Common; Large colliery pond at the Frog Lane Pit, Coalpit Heath; and in a stream running therefrom by Ox Bridge on the Yate road; Old clay pits in a field between Rangeworthy and Wickwar; and in another pool nearer the Midland line a mile east of Rangeworthy; Pond in a pasture on Goose-green Farm, north of Yate;" and "The Gaul Pond, Tortworth Court, A. B. Jackson" (Riddelsdell, 1948).

NITELLOPSIS Hy

Nitellopsis obtusa (Desv.) J. Groves (Starry Stonewort) Wetland Very Rare Discovered for the first time in the Bristol Region in 2003 at both Chew Valley Lake and Blagdon Lake where it's locally abundant and also at Cheddar Reservoir (outside the region) in 2011, suggesting It's possible it could exist in other large bodies of water, such as Barrow Gurney.

NITELLA C. Agardh

Nitella flexilis (L.) C. Agardh (Smooth Stonewort) Wetland Extinct? Only recorded a couple of times: "In the canal; H. Gibbs. in Fl. Bath Suppl." (Murray, 1896) and from a single rhyne near Walton-in-Gordano by O. Mountford and S. Wilson in 1989 - there again the following year (1990) and again in 1999 by A. Nisbet. It could still be present but its very slender and discrete nature makes it hard to find. It’s probable however that these records were actually mistakes for N. opaca which, at the time, was much confused with N. flexilis and the two were often amalgamated as one under the latter name. D. Hawkins has looked for it numerous times in recent years but with no success. But equally there's no reason why this plant wouldn't have occurred somewhere in the region if it doesn't still?
Nitella opaca (Bruz.) C. Agardh (Dark Stonewort) Wetland Extinct Used to occur "In three ponds on Yate Common; discovered in March, 1910 by Mr. C. Bucknall." (White, 1912 & Riddelsdell, 1948) and still present here in 1918. Later found north of this site in 1917 by I.M. Roper? along with the next species near Yate Court and recorded for the first and only time in North Somerset in 1933 at Blagdon Lake by H.S. Thompson. A mysterious species. These are the only records for the region but strategic searches may re-find it.
Nitella mucronata (A. Braun) Miguel var. gracillima J. Groves ex Bullock-Webster (Pointed Stonewort) Wetland Very Rare. Only recorded North of Yate in a few ponds near Rangeworthy, Wickwar and at Tortworth Lake. First discovered in 1917 by I.M. Roper in a "Strontia pit, near Yate Court" (Riddelsdell, 1948). All sites need re-investigating as it hasn't been seen since 1990 but this is no doubt the result of a lack of interest in recording stoneworts and it most likely still exists. It's very slender and so easy to miss.

TOLYPELLA (A. Braun) A. Braun

Tolypella intricata (Trent ex Roth.) Leonh. (Tassel Stonewort) Wetland Very rare Present in various places in the Wickwar & Hawkesbury Upton area. First recorded from an "Old strontia pit below Yate Rocks, 1917, Hb. Sandwith; Yate Common, J. Bot., 1917, 195" (Riddelsdell, 1948). It used to occur in North Somerset at Weston-in-Gordano but it's gone / appears to be dormant now and was last seen here in 1989 by N. Stewart. A number of searches have been made with no success but it's always possible it could one day be rediscovered.

[Found in a beautifully diverse farm pond between Horton Bushes and Lower Woods in 2024 by D. Hawkins - Nature in Avon 2025, p. 194]

Tolypella glomerata (Desv.) Leonh. (Clustered Stonewort) Wetland Very rare Extremely rare but very ephemeral. Most recently recorded at Chew Valley Lake in 2013 By B. Goldsmith and at Nailsea Moor in 2021 by D. Hawkins. Also historically recorded from between Weston-in-Gordano and Clapton-in-Gordano in 1922 by C.I. Sandwith.

Tolypella salina R. Corillion (Saltmarsh Stonewort) Wetland Extinct A very dubious record. Discovered for the first and only time in Britain in 1922 from Portbury on the mudflats by C.I. Sandwith. The record needs tracing.T. salina is limited to the French coast and some Iberian stations. It's possible the plant intended was actually T. nidifica or glomerata; however it is plausible. Portbury was a heavy trading route and all sorts of far-flung aliens have been recorded here - a specialty held by the Sandwith’s.

Nick Stewart:

The specimen is in Leiden and was determined as Tolypella salina by the late Joop van Raam who was one of the most respected charologists internationally. I have the full details somewhere but I am pretty sure that it was from a ditch rather than the mudflats. The record is reported in John et al. 2012 Freshwater Algal Flora of the British Isles and there was no suggestion that it was an alien. It occurs in western France so it is not too big a leap to Bristol although it is typically a species of salterns.

However, the specimen has since been reviewed by Klaus van de Weyer and is now considered to be Tolypella glomerata, which is as it was originally recorded. I think this may be due to a revision of the key diagnostic features.

Sources:

New Phytologist Foundation - Water quality as a threat to aquatic plants: discriminating between the effects of nitrate, phosphate, boron and heavy metals on charophytes

Taxa to be added to Wild Plants of the Bristol Region

In order of Charophytes of Great Britain and Ireland, taken from Brist. Fl, Glos. Fl., Som. Fl., Som. Fl. Sup., and NBN.

Chara vulgaris var. vulgaris (Common Stonewort) - 5 records according to NBN, species status more accurate NBN
Chara vulgaris var. crassicaulis (Common Stonewort) - 1 record according to NBN
Chara vulgaris var. longibracteata (Long-bracted Stonewort?) - 5 records according to NBN
Chara vulgaris var. papillata (Papillate Stonewort?) - 2 records according to NBN
Chara contraria var. contraria (NBN) C. vulgaris var. contraria (Charophytes of Great Britain and Ireland) (Opposite Stonewort - NBN) - 10 records according to NBN
Chara hispida L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN) - Brist. Fl., Glos. Fl. (outside region), Som. Fl., & Som. Fl. Sup.
Chara aculeolata (NBN) Chara pedunculata (Charophytes of Great Britain and Ireland) (Hedgehog Stonewort - NBN) - 6 records according to NBN - As C. polyacantha in Brist. Fl. & Som. Fl. Sup.
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) (Fragile Stonewort - NBN) - As C. fragilis (var. capillacea, var. Hedwigii also) in Brist. Fl., Glos. Fl. (C. globularis var. fragilis), Som. Fl., & Som. Fl. Sup. (var. capillacea, var. Hedwigii also).
Chara virgata var. virgata (NBN) Chara globularis var. virgata (Charophytes of Great Britain and Ireland) (Delicate Stonewort - NBN) - 5 records according to NBN - As C. fragilis var. delicatula / C. delicatula in Brist. and Glos. Fl.
Chara aspera (NBN) var. aspera (Charophytes of Great Britain and Ireland) (Rough Stonewort - NBN) - Som. Fl.
Nitellopsis obtusa (Starry Stonewort - NBN) - 15 records according to NBN
Nitella flexilis (NBN) var. flexilis (Charophytes of Great Britain and Ireland) (Smooth Stonewort - NBN) - Som. Fl.
Nitella opaca (NBN) Nitella flexilis var. flexilis (Charophytes of Great Britain and Ireland) (Dark Stonewort - NBN) - 4 confirmed records according to NBN - Charophytes of Great Britain and Ireland lumps this with the previous but it is accepted as distinct now.
Nitella mucronata var. gracillima (Pointed Stonewort - NBN) - 7 records according to NBN
Tolypella intricata (Tassel Stonewort - NBN) - 11 records according to NBN
Tolypella glomerata (NBN) T. nidifica var. glomerata (Charophytes of Great Britain and Ireland) (Clustered Stonewort - NBN) - 2 records according to NBN

Could occur:

Chara canescens (Bearded Stonewort)
Chara contraria var. hispidula (NBN) Chara vulgaris var. hispidula (Charophytes of Britain and Ireland) (Opposite Stonewort)
Chara baltica (Baltic Stonewort)
Chara rudis (NBN) Chara hispida var. rudis (Charophytes of Britain and Ireland) (Rugged Stonewort)
Chara curta (NBN) Chara aspera var. curta (Charophytes of Britain and Ireland) (Lesser Bearded Stonewort) - should occur
Chara connivens (Convergent Stonewort)
Nitella translucens (Translucent Stonewort) - should occur
Nitella gracilis (Slender Stonewort)
Tolypella prolifera (Great Tassel Stonewort)
Tolypella nidifica (NBN) var. nidifica (Charophytes of Great Britain and Ireland) (Bird's-nest Stonewort - NBN) - Som. Fl. - outside of region

Findings stacked

In order of Charophytes of Great Britain and Ireland, following Brist. Fl, Glos. Fl., Som. Fl., Som. Fl. Sup., and NBN.

Chara vulgaris var. vulgaris
Chara vulgaris L., C. foetida Braun. (var. vulgaris - Charophytes of Great Britain and Ireland, NBN) (Common Stonewort - NBN) - a number of records according to NBN
Chara vulgaris L., C. foetida Braun. (var. vulgaris - Charophytes of Great Britain and Ireland, NBN) (Common Stonewort) - a number of records according to NBN
Chara vulgaris, L. (var. vulgaris - Charophytes of Great Britain and Ireland, NBN) (Common Stonewort) - a number of records according to NBN
Chara vulgaris L. (var. vulgaris - Charophytes of Great Britain and Ireland, NBN) (Common Stonewort) - a number of records according to NBN
Chara vulgaris var. vulgaris (Common Stonewort) - 5 records according to NBN, species status more accurate NBN
Chara vulgaris var. crassicaulis
Chara vulgaris var. crassicaulis (Common Stonewort) - 1 record according to NBN
Chara vulgaris var. longibracteata
var. longibracteata Kütz. (Long-bracted Stonewort?) - 5 records according to NBN
var. longibracteata (Kütz.) Kütz., C. longibracteata Kütz.; C. foetida var. longibracteata (Kütz) Coss. et Germ. (Long-bracted Stonewort?) - 5 records according to NBN
var. longibracteata, Kuetz. (Long-bracted Stonewort?) - 5 records according to NBN
var. longibracteata, Kuetz. (Long-bracted Stonewort?) - 5 records according to NBN
Chara vulgaris var. longibracteata - 5 records according to NBN
Chara vulgaris var. papillata
var. papillata Wallr., C. decipiens Desv. (Papillate Stonewort?) - 2 records according to NBN
var. papillata Wallr. (Papillate Stonewort?) - 2 records according to NBN
var. papillata, Wallr. (Papillate Stonewort?) - 2 records according to NBN
var. papillata, Wallr. (Papillate Stonewort?) - 2 records according to NBN
Chara vulgaris var. papillata - 2 records according to NBN
Chara contraria A. Br. (var. contraria - NBN) C. vulgaris var. contraria (Charophytes of Great Britain and Ireland) (Opposite Stonewort - NBN) - 10 records according to NBN
Chara contraria, Kuetz. (var. contraria - NBN) C. vulgaris var. contraria (Charophytes of Great Britain and Ireland) (Opposite Stonewort - NBN) - 10 records according to NBN
Chara contraria var. contraria (Opposite Stonewort) - 10 records according to NBN
Chara hispida var. hispida
Chara hispida L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN)
Chara hispida L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN)
Chara Hispida, L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN)
Chara hispida, L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN)
Chara pedunculata
Chara aculeolata (NBN) Chara pedunculata (Charophytes of Great Britain and Ireland) Chara polyacantha Braun. (Hedgehog Stonewort - NBN) - 6 records according to NBN
Chara aculeolata (NBN) Chara pedunculata (Charophytes of Great Britain and Ireland) Chara polyacantha, Braun. (Hedgehog Stonewort - NBN) - 6 records according to NBN
Chara aculeolata (Hedgehog Stonewort) - 6 records according to NBN
Chara globularis var. globularis
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) Chara fragilis Desv. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) var. Capillacea Thuill. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) var. Hedwigii.? (Fragile Stonewort - NBN) - "On the Coalpit Heath plant [Large colliery pond at the Frog Lane Pit, Coalpit Heath; and in a stream running therefrom by Ox Bridge on the Yate road] Messrs. H. and J. Groves reported that it was not in good state, and might possibly be the var. Hedwigii."
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) Chara globularis Thuill., var. fragilis (Desv.) W.-Dod., C. fragilis Desv. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) Chara fragilis, Desv. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) C. Hedwigii. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) Chara fragilis, Desv. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) var. Hedwigii, Kuetz. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) var. capillacea, Coss. & Germ. (Fragile Stonewort - NBN)
Chara globularis var. virgata
Chara virgata var. virgata (NBN) Chara globularis var. virgata (Charophytes of Great Britain and Ireland) var. delicatula Braun. (Delicate Stonewort - NBN) - 5 records according to NBN
Chara virgata var. virgata (NBN) Chara globularis var. virgata (Charophytes of Great Britain and Ireland) Chara delicatula Agardh. (Delicate Stonewort - NBN) - 5 records according to NBN
Chara virgata var. virgata (Delicate Stonewort) - 5 records according to NBN
Chara aspera, Willd. (NBN) var. aspera (Charophytes of Great Britain and Ireland) (Rough Stonewort - NBN) - occurs in region - Som. Fl.
Chara aspera, Willd. (NBN) var. aspera (Charophytes of Great Britain and Ireland) (Rough Stonewort - NBN)
Nitellopsis obtusa
Nitellopsis obtusa (Starry Stonewort) - 15 records according to NBN
Nitella flexilis var. flexilis
Nitella flexilis, Agardh. (var. flexilis - Charophytes of Great Britain and Ireland) (Smooth Stonewort - NBN) - occurs in region - Som. Fl.
Nitella opaca Ag. (NBN) Nitella flexilis var. flexilis (Charophytes of Great Britain and Ireland) (Dark Stonewort - NBN) - 4 confirmed records according to NBN
Nitella opaca (Agardh ex Bruzelius) Agardh, Chara opaca Agardh ex. Bruzelius. (Dark Stonewort - NBN) - 4 confirmed records according to NBN
Nitella opaca, Agardh. (Dark Stonewort - NBN) - 4 confirmed records according to NBN
Nitella opaca, Agardh. (Dark Stonewort - NBN) - 4 confirmed records according to NBN
Nitella opaca (Dark Stonewort) - 4 confirmed records according to NBN
Nitella mucronata
Nitella mucronata (Braun) Miquel., Chara mucronata Braun., var. gracillima Groves et B.-W., var. nov. (Pointed Stonewort - NBN) - 7 records according to NBN
Nitella mucronata var. gracillima (Pointed Stonewort) - 7 records according to NBN
Tolypella intricata
Tolypella intricata (Roth) Leonh., Chara intricata Roth. (Tassel Stonewort - NBN) - 11 records according to NBN
Tolypella intricata, Leonh. (Tassel Stonewort - NBN) - 11 records according to NBN
Tolypella intricata (Tassel Stonewort) - 11 records according to NBN
Tolypella nidifica (Müll.) Leonh., Conferva nidifica Müll. (var. nidifica - Charophytes of Great Britain and Ireland) (Bird's-nest Stonewort - NBN) - not in region
Tolypella nidifica var. glomerata (Tolypella glomerata - NBN)
Tolypella glomerata (Desv.) Leonh., Chara glomerata Desv. (T. nidifica var. glomerata - Charophytes of Great Britain and Ireland) (Clustered Stonewort) - 2 records according to NBN
Tolypella glomerata, Leonh. (T. nidifica var. glomerata - Charophytes of Great Britain and Ireland) (Clustered Stonewort) - 2 records according to NBN
Tolypella glomerata (Clustered Stonewort) - 2 records according to NBN

Could occur:

Species stacked

Chara canescens (Bearded Stonewort)
Chara vulgaris var. contraria (Chara contraria var. contraria - NBN) (Opposite Stonewort - NBN) - does occur
Chara vulgaris var. hispidula (Chara contraria var. hispidula - NBN) - not to be confused with the above
Chara contraria var. hispidula (Opposite Stonewort)
Chara baltica
Chara baltica (Baltic Stonewort)
Chara hispida var. hispida (Chara hispida sensu stricto - NBN) - does occur - Brist. Fl.
Chara hispida (Bristly Stonewort)
Chara hispida var. major (Chara hispida - sensu stricto - NBN)
Chara hispida var. rudis (Chara rudis - NBN)
Chara rudis (Rugged Stonewort)
Chara globularis (Fragile Stonewort) - does occur - Brist. Fl.
Chara aspera var. aspera (Chara aspera - NBN) - does occur - Som. Fl.
Chara aspera (Rough Stonewort)
Chara aspera var. curta (Chara curta - NBN) - should occur
Chara curta (Lesser Bearded Stonewort)
Chara connivens
Chara connivens (Convergent Stonewort)
Nitella flexilis (Smooth Stonewort) - does occur - Som. Fl.
Nitella translucens - should occur
Nitella translucens (Translucent Stonewort)
Nitella gracilis
Nitella gracilis (Slender Stonewort)
Tolypella prolifera
Tolypella prolifera (Great Tassel Stonewort)
Tolypella nidifica var. nidifica (Tolypella nidifica - NBN) - does occur
Tolypella nidifica (Bird's-nest Stonewort)

Workings out:

Brist. Fl.

Nitella opaca Ag. (NBN) Nitella flexilis var. flexilis (Charophytes of Great Britain and Ireland) (Dark Stonewort - NBN) - 4 confirmed records according to NBN
Chara vulgaris L., C. foetida Braun. (var. vulgaris - Charophytes of Great Britain and Ireland, NBN) (Common Stonewort - NBN) - a number of records according to NBN
var. longibracteata Kütz. (Long-bracted Stonewort?) - 5 records according to NBN
var. papillata Wallr., C. decipiens Desv. (Papillate Stonewort?) - 2 records according to NBN
Chara contraria A. Br. (var. contraria - NBN) C. vulgaris var. contraria (Charophytes of Great Britain and Ireland) (Opposite Stonewort - NBN) - 10 records according to NBN
Chara hispida L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN)
Chara aculeolata (NBN) Chara pedunculata (Charophytes of Great Britain and Ireland) Chara polyacantha Braun. (Hedgehog Stonewort - NBN) - 6 records according to NBN
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) Chara fragilis Desv. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) var. Capillacea Thuill. (Fragile Stonewort - NBN)
Chara virgata var. virgata (NBN) Chara globularis var. virgata (Charophytes of Great Britain and Ireland) var. delicatula Braun. (Delicate Stonewort - NBN) - 5 records according to NBN
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) var. Hedwigii.? (Fragile Stonewort - NBN) - "On the Coalpit Heath plant [Large colliery pond at the Frog Lane Pit, Coalpit Heath; and in a stream running therefrom by Ox Bridge on the Yate road] Messrs. H. and J. Groves reported that it was not in good state, and might possibly be the var. Hedwigii."

Glos. Fl.

Chara virgata var. virgata (NBN) Chara globularis var. virgata (Charophytes of Great Britain and Ireland) Chara delicatula Agardh. (Delicate Stonewort - NBN) - 5 records according to NBN
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) Chara globularis Thuill., var. fragilis (Desv.) W.-Dod., C. fragilis Desv. (Fragile Stonewort - NBN)
Chara hispida L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN)
Chara vulgaris L., C. foetida Braun. (var. vulgaris - Charophytes of Great Britain and Ireland, NBN) (Common Stonewort) - a number of records according to NBN
var. longibracteata (Kütz.) Kütz., C. longibracteata Kütz.; C. foetida var. longibracteata (Kütz) Coss. et Germ. (Long-bracted Stonewort?) - 5 records according to NBN
var. papillata Wallr. (Papillate Stonewort?) - 2 records according to NBN
Tolypella nidifica (Müll.) Leonh., Conferva nidifica Müll. (var. nidifica - Charophytes of Great Britain and Ireland) (Bird's-nest Stonewort - NBN)
Tolypella glomerata (Desv.) Leonh., Chara glomerata Desv. (T. nidifica var. glomerata - Charophytes of Great Britain and Ireland) (Clustered Stonewort) - 2 records according to NBN
Tolypella intricata (Roth) Leonh., Chara intricata Roth. (Tassel Stonewort - NBN) - 10 records according to NBN
Nitella mucronata (Braun) Miquel., Chara mucronata Braun., var. gracillima Groves et B.-W., var. nov. (Pointed Stonewort - NBN) - 7 records according to NBN
Nitella opaca (Agardh ex Bruzelius) Agardh, Chara opaca Agardh ex. Bruzelius. (Dark Stonewort - NBN) - 4 confirmed records according to NBN

Som. Fl.

Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) Chara fragilis, Desv. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) C. Hedwigii. (Fragile Stonewort - NBN)
Chara aspera, Willd. (NBN) var. aspera (Charophytes of Great Britain and Ireland) (Rough Stonewort - NBN)
Chara Hispida, L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN)
Chara vulgaris, L. (var. vulgaris - Charophytes of Great Britain and Ireland, NBN) (Common Stonewort) - a number of records according to NBN
var. longibracteata, Kuetz. (Long-bracted Stonewort?) - 5 records according to NBN
var. papillata, Wallr. (Papillate Stonewort?) - 2 records according to NBN
Nitella flexilis, Agardh. (var. flexilis - Charophytes of Great Britain and Ireland) (Smooth Stonewort - NBN)
Nitella opaca, Agardh. (Dark Stonewort - NBN) - 4 confirmed records according to NBN

Som. Fl. Sup.

Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) Chara fragilis, Desv. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) var. Hedwigii, Kuetz. (Fragile Stonewort - NBN)
Chara globularis (NBN) var. globularis (Charophytes of Great Britain and Ireland) var. capillacea, Coss. & Germ. (Fragile Stonewort - NBN)
Chara aspera, Willd. (NBN) var. aspera (Charophytes of Great Britain and Ireland) (Rough Stonewort - NBN)
Chara aculeolata (NBN) Chara pedunculata (Charophytes of Great Britain and Ireland) Chara polyacantha, Braun. (Hedgehog Stonewort - NBN) - 6 records according to NBN
Chara contraria, Kuetz. (var. contraria - NBN) C. vulgaris var. contraria (Charophytes of Great Britain and Ireland) (Opposite Stonewort - NBN) - 10 records according to NBN
Chara hispida, L. (NBN) var. hispida (Charophytes of Great Britain and Ireland) (Bristly Stonewort - NBN)
Chara vulgaris L. (var. vulgaris - Charophytes of Great Britain and Ireland, NBN) (Common Stonewort) - a number of records according to NBN
var. longibracteata, Kuetz. (Long-bracted Stonewort?) - 5 records according to NBN
var. papillata, Wallr. (Papillate Stonewort?) - 2 records according to NBN
Tolypella glomerata, Leonh. (T. nidifica var. glomerata - Charophytes of Great Britain and Ireland) (Clustered Stonewort) - 2 records according to NBN
Tolypella intricata, Leonh. (Tassel Stonewort - NBN) - 10 records according to NBN
Nitella opaca, Agardh. (Dark Stonewort - NBN) - 4 confirmed records according to NBN

NBN

Chara aculeolata (Hedgehog Stonewort) - 6 records according to NBN
Chara contraria var. contraria (Opposite Stonewort) - 10 records according to NBN
Chara virgata var. virgata (Delicate Stonewort) - 5 records according to NBN
Chara vulgaris var. vulgaris (Common Stonewort) - 5 records according to NBN, species status more accurate NBN
Chara vulgaris var. crassicaulis (Common Stonewort) - 1 record according to NBN
Chara vulgaris var. longibracteata - 5 records according to NBN
Chara vulgaris var. papillata - 2 records according to NBN
Nitella mucronata var. gracillima (Pointed Stonewort) - 7 records according to NBN
Nitella opaca (Dark Stonewort) - 4 confirmed records according to NBN
Nitellopsis obtusa (Starry Stonewort) - 15 records according to NBN
Tolypella glomerata (Clustered Stonewort) - 2 records according to NBN
Tolypella intricata (Tassel Stonewort) - 11 records according to NBN

Could occur:

Chara aspera (Rough Stonewort)
Chara baltica (Baltic Stonewort)
Chara canescens (Bearded Stonewort)
Chara connivens (Convergent Stonewort)
Chara contraria var. hispidula (Opposite Stonewort)
Chara curta (Lesser Bearded Stonewort)
Chara globularis (Fragile Stonewort)
Chara hispida (Bristly Stonewort)
Chara rudis (Rugged Stonewort)
Nitella flexilis (Smooth Stonewort)
Nitella gracilis (Slender Stonewort)
Nitella translucens (Translucent Stonewort)
Tolypella nidifica (Bird's-nest Stonewort)
Tolypella prolifera (Great Tassel Stonewort)

Charophytes of Great Britain and Ireland

Chara vulgaris var. vulgaris
Chara vulgaris var. crassicaulis
Chara vulgaris var. longibracteata
Chara vulgaris var. papillata
Chara hispida var. hispida
Chara pedunculata
Chara globularis var. globularis
Chara globularis var. virgata
Nitellopsis obtusa
Nitella flexilis var. flexilis
Nitella mucronata
Tolypella intricata
Tolypella nidifica var. glomerata (Tolypella glomerata - NBN)

Could occur:

Chara vulgaris var. contraria
Chara vulgaris var. hispidula (Chara contraria var. hispidula - NBN)
Chara baltica
Chara hispida var. hispida (Chara hispida sensu stricto - NBN)
Chara hispida var. rudis (Chara rudis - NBN)
Chara hispida var. major (Chara hispida - sensu stricto - NBN)
Chara aspera var. aspera (Chara aspera - NBN)
Chara aspera var. curta (Chara curta - NBN)
Chara connivens
Nitella translucens
Nitella gracilis
Tolypella prolifera
Tolypella nidifica var. nidifica (Tolypella nidifica - NBN)