Anyone out surveying today? Surrey. 35°C heat, a Sparrowhawk landed beside me at a pond, looking exhausted. It drank, stood in the water to recover, & then started watching newts in the shallows which were swimming through the Stoneworts (N. flexilis agg.). Phone gave up in the heat after that.

Algal succession in a New Forest stream. First came the Planktothrix isothrix bloom (not good). Then Cladophora glomerata. Now Characium sp. colonising the Cladophora. Even in drought, these streams remain remarkably dynamic, with one community paving the way for the next. #phycology

#StillFlowering Streams in the New Forest are drying down after a prolonged lack of rain. Unexpectedly, this Lesser Water-plantain (Baldellia ranunculoides) is still flowering in a dry stream bed. Some species may prove to be winners, but what will we lose if these droughts become the norm?

Coral-necklace (Illecebrum verticillatum). Not #StillFlowering. These are seeds, not flowers. This lovely little annual seems to be increasing in the New Forest, perhaps benefiting from the bare ground created by recent drought years. #WildflowerHour

One of my fave finds: Water net (Hydrodictyon reticulatum). A freshwater green alga that grows remarkable net-like colonies that are visible to the naked eye. Each delicate mesh is made up of hundreds of interconnected cells. It's an uncommon species in Britain, but it can be locally abundant.

Bright yellow Marsh Ragwort (Jacobaea aquatica) flowering among Branched Bur-reed (Sparganium erectum) in a New Forest pond. Winter flooding would kill many plants, but not Marsh Ragwort. It has evolved a way of storing energy in its roots, allowing it to cope with long periods of waterlogging.

For #InvasiveSpeciesWeek & #WildflowerHour, a more familiar invader: American Skunk-cabbage (Lysichiton americanus). New Forest. The story: fallen spadix is still packed with seeds, & nearby, a dense patch of seedlings from last year's. Once established, this striking ornamental can spread rapidly.

For #InvasiveSpeciesWeek and #WildflowerHour, here's an emerging threat rather than one of the familiar invaders. Red-stemmed Parrot's-feather (Myriophyllum rubricaule), not better-known Parrot's-feather. Introduced through the aquatic plant trade, it has already established in a New Forest bog.

A nice surprise in the New Forest yesterday: Brown Beak-sedge (Rhynchospora fusca). It was growing in a pond where the reed had been cut the previous autumn, and the cut stems had drowned over winter. Among the old reed stubble, this uncommon species was emerging into the newly opened conditions.

On a muddy stream margin today: Hampshire-purslane (Ludwigia palustris). Fruits float when mature, allowing them to disperse locally along streams & flooded ground. Light needed for germination, so freshly exposed mud ideal, but unlike some wetland species, drying does seem to stimulate germination.

36°C in the New Forest today. Callitriche brutia ssp. hamulata from a river. The "spanner" leaf tips broad and distinctive. I usually find ssp. hamulata in rivers, while ssp. brutia more in ponds that dry back during summer. I wish I were an aquatic plant today. 🌿

A hot day for wearing waders today, but pleased to find a member of the Ranunculus penicillatus complex in a river. An intriguing New Forest record. The taxonomy is complex, but it is certainly not R. penicillatus subsp. pseudofluitans. 🌿 Heat rash on my ankles, and a long drink afterwards.🧉

For #WildflowerHour: Waders on and out into the water. Spiked Water-milfoil (Myriophyllum spicatum), a submerged aquatic plant sending its flowering spikes above the surface like the Lady of the Lake raising a sword from the water. #AquaticPlants #Ponds #Botany 🌿💧

Spearwort, Coral-necklace, Pennyroyal, Hampshire-purslane & other New Forest pond/wet species. But the pony is the real story. Without grazing, trampling & poaching by commoners' stock, much of this remarkable diversity would be lost. I'm grateful to everyone who helps keep those traditions alive.♥️🐎

Branched Bur-reed (Sparganium erectum) in full flower today in the New Forest. It was striking that the early-season flowers had failed to set in the cool spell we had, but the current ones are producing fruit.

Very pleased to bump into Narrow-leaved Lungwort (Pulmonaria longifolia) while surveying a stream today in the New Forest. It doesn't seem to spread from seed, so the clump will likely be there when I comeback to resurvey that section. A good marker.

Attractive sedges in the New Forest yesterday. Waders on and out in the water. Cyperus Sedge (Carex pseudocyperus) Bladder-sedge (Carex vesicaria)

Beautiful, serene Lesser Water-plantain (Baldellia ranunculoides) in the New Forest. Moments after taking this photo, I looked down and realised my movements had attracted Medicinal Leeches. At least three were climbing over each boot.

An early morning taxonomy black hole. After discussing Valeriana officinalis agg, I tried to trace how the traditional British taxa fits current POWO treatment. V. officinalis ssp. sambucifolia is now placed within V. excelsa, apparently reflecting the relationship with the higher-ploidy aggregate.

Reconnaissance visit to Old River Lea, Hackney Marshes in search of Water-crowfoots -not found- but revealed Nitella mucronata! I checked it repeatedly over lunch, partly because finding a stonewort in an urban London river seemed sufficiently improbable that I suspected wishful thinking on my part.

Three years to the day after my first visit to Braughing Meads, I revisited the Scarce Tufted-sedge (Carex cespitosa) population. The plants were very much affected by the dry spring.

@ilichenmoss2.bsky.social George Greiff in the BBC News headlines on Sunday morning. A fantastic discovery, and hopefully a way to moderate invasive (INNS) Campylopus introflexus (Heath Star Moss). Well deserved recognition for some very interesting bryological work. 🎉🙌 www.bbc.co.uk/news/article...

Killer fungus discovered that destroys UK invasive plant

A newly discovered species raises hope that some native British habitats could be restored.

bbc.co.uk

A great day to stay inside, away from the heat, and do some writing. Finished work on a paper on Mediterranean temporary ponds & a charophyte. Musing on how best to promote unattractive aquatic plants & persuade people to care about our less-charismatic taxa. Fascinating Plants! #NotJustaMuddyPuddle

Collecting crowfoot -Herts river today. Fast flow, clean gravel, carp, damselflies. Beautiful at first glance. Look closer & plants festooned with Cladophora glomerata & Ulva intestinalis, while the air carries the lingering scent of laundry fragrance. A chemically altered river still looks idyllic.

This week a #WildFlowerShow for #WildflowerHour Sampling a unique non-(poorly-) flowering Crowfoot in a river, and was suddenly besieged by carp. They carve channels through the Crowfoot and thump into my waders. So far, the only UK river with this Crowfoot- doesn't look exciting without flowers.

Just over one year on from planting, the Carex cespitosa reintroduction at Fir and Pond Wood is looking extraordinary. Huge tussocks, abundant fruiting, and plants that already look completely at home in the site.

I’m beginning to suspect Nitella opaca may be the dominant Nitella of the N. flexilis/ opaca agg. in southern England. The interesting bit is why this may have been overlooked. After May, N. opaca and N. flexilis become much harder to separate reliably as the antheridia decay, detach or are lost.

Walking from one survey to another this week in the New Forest, and very pleased to see winter inundations with these lovely little plants. ♥️🌿 Shoreweed (Littorella uniflora) Small Cudweed (Logfia minima) Heath Pearlwort (Sagina subulata) Blinks (Montia fontana subsp. chondrosperma)

I love the different flavours of the Menorcan temporary ponds I visited recently. So ephemeral. These shallow peats in sandstone depressions near Ferreries were especially striking, a classic Mediterranean ephemeral wetland system, winter-wet and quietly structured by seasonal saturation.

A glorious dawn and Happy May Day all! Madrigals from the church tower and a very different setting from the beginning of the week, surveying ponds! Lots of sample sorting today, and plant vouchers cleaned and pressed. I will start after my second cup of coffee.