It seems to me that although glassort (Salicornia dolichostachya) is a very simple name it reflects what must be quite a complex story. It is certainly a simple plant, basically just a green plant with no apparent flower, upright and branched, a bit like a small cactus I suppose. It starts green in May then turns yellowish before reaching reddish brown by September. It is plant found solely on saltmarsh and is very common at the western end of Poole harbour and it also occurs on tidal mudflats elsewhere in the county.
I cannot find much else to say about the plant itself other than it has a salty taste (from the sea water of course) and is used in salads in posh restaurants around here. In hope of more I turn to the Internet and, sure enough, there is stacks of information about this plant and its relatives. Its resistance to salinisation is being studied in some depth to see if it has genetic content that might help make crops salt resistant in other parts of the world where the soil is becoming more saline as the level sea rises. It is all very complicated but it is all there to read in papers if you are interested!
And glasswort must have some connection to glass? Sure enough, its ashes where used in the production of glass until the middle of the 19th century when better chemical formulae were created.
Opposite-leaved Golden Saxifrage: sepals no petals
Where you find shallow water in streams you will sometimes find a mat of leaves with small yellow flowers amongst them, this is the opposite-leaved golden saxifrage (Chrysosplenium oppositifolium). The leaves are visible for much of the year but the flowers only from February until May. I have said that the flowers are yellow but that is not entirely true, it is the impression the plant gives. In reality the plant has no petals but it does have yellowish green sepals and bright yellow anthers.
This is quite a distinctive plant and quite unmistakable when you find it. The opposite-leaved golden saxifrage is common across Dorset in suitable habitat but the alternate-leaved golden saxifrage is absent from the county, it is a mountain species, and so confusion should not arise.
Marsh Pennywort: the answer lies in the leaves
The vegetation in wet areas of heath is, naturally, very different to that of dry heath. Whilst some plants occur in both, in general each species has its preference for areas of wet mire and bog or dry, sandy soil. It should not come as a surprise, then, that marsh pennywort (Hydrocotyle vulgaris) favours damp bog and fen. It also has a preference for acid conditions so the wet areas on the Dorset heaths is a place you are likely to find it.
If you are looking for a flower to identify it by you are most likely going to struggle because the flowers are very small, green in colour and are formed in a tight ball so although flowers are present from June in to August they are not readily visible! Fortunately the leaves are quite distinctive being disc-like forming a very shallow cone. The leaves recall water-lily in some ways as they tend to float on standing water if present.
Not over common in my experience but where it does occur it is likely to cover quite a large area and so it is quite easy to spot once you recognise those leaves.
White Water-lily: padded up
I think I am right in saying that there are no native British species of white water-lilies (Nymphaea agg). Imported for water gardens in past times they have established themselves in ponds and lakes pretty much everywhere; indeed we have them in our garden pond. There are various species you may encounter, mainly of the family Nymphaea and rather then attempt to write abut all of them I have grouped themselves together which is where the agg. in the scientific name comes from - aggregated.
Although introduced there do seem to good for native wildlife. Hoverflies, dragonflies and damselflies like to bask on the leaves which are also popular with pond skaters who want to haul themselves off of the water surface for some personal grooming. Water snails are frequent on the undersides of the pads and frogs often hide by them whilst cooling off in the heat of the day. I am not sure the flowers are quite so beneficial as the leaves but they do add a touch of glamour!
I believe the species in my photograph is Nymphaea alba which is one of the most common.
Yellow Water-lily:the brandy glass
It is not unusual to find water-lilies in ponds and more often than not they are white ones which have 'escaped' into the wild. The yellow water-lily (Nuphar lutea) however is different and not just because it is yellow! It is a native species and I think I am right in saying it is our only native water-lily. Secondly, it seems to be more often seen in slow moving rivers rather than in ponds and all of my observations have been from the River Stour in Dorset. Then, the flower heads are on stalks rather than resting on the water surface; this reduces the resistance to the moving water and so protects the flower. The petals on white water-lilies tend to open out forming a star but on the yellow lily the curve upwards cupping the central stamens and style
The plant apparently has a faint smell of brandy and with the upturned petals making a cup shaped this flowers is nicknamed the brandy glass.
Common Reedmace: Moses in the bulrushes
Common Reedmace (Typha latifolia) is a familiar plant of ponds, slow moving rivers and swamps and is often, mistakenly, called the bulrush. I guess, for many of us older people, this will always be connected with pictures in our school Bibles of Moses in the bulrushes! In fact, if you look in a field guide of grasses, sedges, rushes and reeds you will not find this plant at all, you need to look in a wild flower guide as, although it thrives in similar habitat to reeds and sedges, it is totally unrelated.
I will leave it to real botanists to muse over why this is a flower and not a grass but, regardless of its classification, is a 'functional' plant. The attractive brown pods it produces are packed full of seeds which split when ripe and the seeds fall, or are blown, on to the water where they get gradually washed to a muddy area where they settle, germinate and produce more reedmace.
Not a great food source for insects perhaps but reed buntings, bearded tit and other birds do like the seeds.
Broad-leaved Pondweed: superficial interest
It is very easy to look into ponds and lakes, even slow moving rivers, and see a lot of leaves on the water's surface and yet take no notice. If there were bright yellow or large white flowers we would take note; "what lovely water-lilies!". But just, apparently, leaves; who is interested?
These leaves can be produced by a number of plants but the pondweed family are responsible for many and as such are appropriately named. The broad-leaved pondweed (Potamogeton natans) is one of the most common species and has rounded green leaves, smaller than a water-lily but much larger than a duckweed. It is not just leaves, however, as it produces a few stout spikes of pale yellow flowers but the leaves still seem more conspicuous than the flower stalks.
There are several pondweed species, few are common and some are escapes from water gardens so in fresh water ponds and lakes the most likely one you will encounter is the broad-leaved pondweed.
Bog Pondweed: the floating voter
Stop and look into any pool formed on the Dorset heathlands and you may well see bog pondweed (Potamogeton polygonifolius) growing. Pondweeds are quite common on still water and here are various species but, as the name suggests, bog pondweed is the one you are most likely to see growing in acid water and that means, in Dorset, on the heaths.
The leaves mainly float on the surface of the water but some occasionally protrude above and others remain submerged. I suspect varying water levels due to rainfall and evaporation may have something to do with this. It can survive if the water disappears completely and you can encounter it on muddy surfaces with no water present. The leaves look dead and over because, although they start green they quickly turn to their natural colour, reddish brown (that probably comes from the chemistry of the water). The leaves are narrow and pointed witch also helps distinguish it from its most common relative, broad-leaved pondweed. The flowers appear on spikes that emerge from the water above the leaves; these too are reddish brown in colour. They look a bit like plantain flowers and have no petals.
This plant can sometimes be found in garden ponds provided the water is acidic enough but it can be quite invasive so I would not seek to try and encourage it in our pond!