Dicotyledonous Plants  of the local Shingle Seashore

By Peter Jones

Background to this article

In 2022 Julia Jones took photos of some plants growing on the beach on the Bawdsey Side of the river deben and asked members of the RDA to help with identification [Plants of the Deben – a plea for help – River Deben Association]. 

Bawdsey Beach, July 2022

One of the problems of doing so was because some of the photos were not very sharp.  The usual reason for this if they were taken on a smartphone is not the quality of the camera but because smartphones are very light, have to be held away from the body in order to see the screen, are difficult to keep absolutely still,  particularly if it is windy (which it usually is at the seaside), so move very slightly during the exposure (the problem varies slightly with the lighting conditions – exposures are longer in lower light conditions, so even very slight movement can cause slight blurring). 

I therefore offered to try to obtain clearer photos using my DSLR camera which is heavier and held against the face in use.  I did not make special visits to take photos and it happened that I was never there when the few and sparsely scattered grasses were in flower, so they have not, so far, been included.   There are also some patches of lichen to be found here and there and I have neither expertise nor reference books to enable accurate identification of these (I suspect this is a group of organisms, like some larger fungi, where amateurs make quick confident identifications but experts are more guarded.).

Below are photographs of 14 species of dicotyledonous plants but there are certainly more, including a vetch (or perhaps two) photographed along with other plants but unidentifiable because they were not in flower and some other plants which were either before or after flowering at the times of my visits.  To compile a comprehensive list would require systematic searching of the area on visits at reasonably close intervals over an entire growing season or more.

Editors note: Dicotyledonous plants are one of the two main groups of all flowering plants. They typically have two embryonic leaves either side on the seed head

Recent History of the Onshore Shingle at the mouth of the Deben

When I first visited the mouth of the river some 20 years ago the shingle facing the sea reached by the path from Bawdsey Quay only extended some 20-30m beyond the rusty sheet piling but in the last few years it has extended much further,  I would guess it is now about 80 -100m from the piling to the water.  A bit further north, north of Bawsey Manor,  the beach has eroded and the cliffs have become very unstable, resulting in the closure of that part of the Suffolk Coast and Heaths Path and a diversion via the roads.

Cliff Erosion Bawdsey, July 2022

South of the river (Felixstowe side) at that time the water mostly came up to the sea wall at HW springs. Because of concern about erosion of the beach and possible undermining and toppling of the sea wall barge loads of rock were brought (from Norway I believe) and rock armour installed at  the slight ness just south of  the houses, where the strong ebb current combined with the waves was scouring away the shore. Also rock groynes were installed along the beach at intervals from there towards  the beach huts and steps down the cliff just south of the Golf Clubhouse. Since then the shingle south of the rock armour has built up hugely and only the landward ends of four of the groynes remain visible, the outer ends of those and the whole of the rest being a few metres deep in the shingle ( still visible are the tall poles, but now projecting only about 2m from the shingle, which marked the outer ends of the hidden groynes as a warning  when the groynes were covered by the tide rather than shingle).  By 2010 the groynes had been covered and the shingle extended quite a long way seaward of them but at that time there was scarcely any vegetation on it. By 2014 there was quite widespread vegetation but not as varied as it is now, from the photo it seems to have been mainly grasses.

Looking South towards Golf Clubhouse, March 2024

As found either side of the mouth of the River Deben

Development of Plants on the Shingle

Once the shingle builds high enough not to be covered by normal spring tides a variety of plants begin to colonise it, in spite of the salt spray and the failure of shingle to retain much water.  It would appear from what has happened in our local areas  that nature and speed of colonisation is related to the size of the shingle, probably because smaller sized stones are likely to retain some sand and so retain rainwater a little better.  With time the decaying parts of early colonisers do accumulate a bit and help to retain more rainwater, and more species colonise it, including some common plants from non-maritime areas.

So far only a few species have been found on the shingle north of the river (Bawdsey side), notably the early colonisers Sea kale, Horned poppy and Sea pea and the vegetation is sparse  (see photo below), although there is a fairly rich flora on the sand and fine shingle behind the sheet steel piling (to be dealt with in a separate article).

Bawdsey Beach between river mouth and Manor and cliffs, April 2023

The contrast with the vegetation south (Felixstowe side) of the river mouth is huge.

Looking  North from near Martello Tower T, near the southern end of the golf links. Bawdsey Manor in the distance.  Line of posts marks ends of rock groynes which are now buried deep beneath the shingle.

1.  Seakale,  Crambe maritima (thought to be one of the ancestors of our cultivated Brassicas) – early coloniser. 

April Early June

Mid – Late June

 July – October – seed pods, 1-seeded so don’t split open

Small seedlings can appear in autumn.

2. Red Valerian, Kentranthus/Centranthus ruber (note white variety arising naturally, pale pink also occurs)

Also occurs inland -was originally introduced but now very widely established in the wild, particularly on light soils (noted growing uninvited in gardens in Woodbridge and in Ramsholt churchyard, for example). Plants often much smaller if growing among dense vegetation.

3. Sea Pea, Lathyrus maritimus – prostrate habit so not distinctive from a distance, except for dark green colour. but obvious close to – distinctive leaves enable identification even when there are no flowers or pods. Can form quite large mats. Very definitely not edible as Lathyrus species (including sweet peas in gardens) contain a toxin.

4. Horned poppy, Glaucium flavum

July – note very long seed pods from which the epithet ‘horned’ arises

The very distinctive leaf shape can enable confident identification when not flowering (see below)

Horned poppy  – young plants found later in the year



5. Welted thistle, Carduus crispus

6. Sea spurge, Euphorbia paralias

7. Curled dock, Rumex crispus

 8. Sea campion, Silene maritima

Flowers resemble white campion but are borne singly on short stalks arising from a low growing mat of flowering and non-flowering shoots.

9. Groundsel

10. Thyme-leaved sandwort, Arenaria serpyllifolia (growing among non-flowering sea pea). Resembles chickweed but petals entire (chickweed petals deeply cleft – there appear to be 10, not 5) 

  11. Dovesfoot cranesbill, Geranium molle

12. Red dead-nettle, Lamium purpureum

13. Ribwort plantain, Plantago lanceolata

14. Hoary cress, Cardaria draba (growing with Groundsel and an unidentified vetch etc)

Something to watchout for?

On the beach at Harwich there are some patches of Rosa rugosa growing flat on the shingle and as there are quite a lot of this species planted and growing vigorously in the gardens north of the Spa Pavilion it would not be too surprising if eventually some seeds arrived on the shingle near the Deben.

Rosa rugosa at Harwich on the beach south of the harbour authority building and small harbour where the pilot launches live

Peter Jones

Peter took an honours course in Botany at Bristol University, with Zoology and Microbiology subsidiary subjects,  in the 1950s.  After graduation  he did  a short spell of research in in Mycology, leading to MSc.  For most of his career he was a plant pathologist,  latterly working for 24 years in Harpenden, Herts. for the Ministry of Agriculture, Fisheries and Food in a small unit responsible for considering the efficacy of agricultural and horticultural and garden pesticides submitted for official approval. 

In 2021 he moved to Woodbridge in order to be able to have a small yacht close by. 

While arthritis has limited his walking range in later years, he has been in the habit of visiting and photographing the Deben and Ore entrances each Spring, at low water springs, to see how they have changed over the winter, and also during the Summer.  In the 1980s he and his wife chartered small yachts each year, several times from the Blackwater,  and so became familiar with this coast from seaward but unfortunately his beloved sailing partner died in 1994.