Dr Astrid Biddle
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astridbiddle.bsky.social
Dr Astrid Biddle
@astridbiddle.bsky.social
Joint BSBI and BBS recorder for Hertfordshire.
🌱Celebrating the joy of Botany and Bryology.
❤️Aquatic plants & many other. Scarce Tufted-sedge. Plant ecology. Rivers, ponds & lakes.
Today I recorded 272 Scarce Tufted-sedge (Carex cespitosa) today — a 72.5% survival rate at Panshanger Park! It’s the driest site and completely rain-fed, which made things tough this summer.

NE Species Recovery Capital Grant, awarded to HMWT.
November 8, 2025 at 9:23 PM
Reposted by Dr Astrid Biddle
The new Red List for Vascular Plants published this week by @bsbibotany.bsky.social highlights the serious decline in Britain’s freshwater plants.
November 7, 2025 at 10:24 AM
🌿 Scarce Tufted-sedge (C. cespitosa) monitoring at Fir & Pond Woods (HMWT Reserve).

Early planting in very high winter water levels, then months of drought — a real test of resilience, aided by pre-tussock formation.

Still, 71 % establishment success! 💪

@naturalengland.bsky.social
October 18, 2025 at 8:39 PM
I've been growing my Vaucheria algae for six days, so far & producing antheridia & oogonia. That means I can identify it to species level. This one was from Port Meadow.
We are beginning to suspect that they can indicate fine habitats, perhaps those of long management continuity.
Ready on Sunday?
October 17, 2025 at 10:34 AM
I wanted to look at the Mudwort (Limosella aquatica) at Port Meadow this weekend, following the report of it by @trisnorton.bsky.social
I wanted to find the Smut fungus Doassansia limosellae, which was last seen in the UK in 1929. No luck though.
Here is Mudwort in flower!
@bsbibotany.bsky.social
October 12, 2025 at 7:27 PM
Completely blown away today by how the Scarce Tufted-sedge (Carex cespitosa) was faring on the River Gade.
It was with trepidation that I entered the river. Vegetation had grown tall this summer. 2025 was one of the worst for reintroducing a wetland plant. Summer drought followed high winter water.
October 5, 2025 at 5:20 PM
A mere ten days ago I was at the 17th International Symposium on Aquatic Plants in Lisbon. Here on the field trip:
A Cladium Mariscus Saw Sedge floating mat in the River Sado, topped with Salix atrocinerea. Other species were Royal Fern (Osmunda regalis), and Marsh Fern (Thelypteris palustris).
October 1, 2025 at 7:23 PM
I was looking through my photos from Porto from earlier this year.
Strapwort (Corrigiola litoralis) had been looking very fine. It grew with Coral-necklace (Illecebrum verticillatum) on a path with a seepage running across it. What a lovely plant!
September 28, 2025 at 7:31 PM
OK, so the Cambs Fenland drains had a Water-plantain. The leaves had perished in the summer, & it may have been either A. plantago-aquatica or A. lanceolatum.
Luckily, it was fruiting.
A) A. plantago-aquatica= achenes had a single furrow on the back.
B) A. lanceolatum= two furrows.
Answer is A.
September 27, 2025 at 8:55 PM
Sphagnum squarrosum in a swampy woodland pond in the New Forest on Monday. Such a pretty moss!
September 24, 2025 at 6:11 AM
I spotted an Asian Hornet in Portugal. It was surprisingly unafraid. I saw there were 344 records for this species in the Lisbon area.
September 21, 2025 at 6:01 PM
A fight going on in the rice fields of the Tagus Estuary near Lisbon.
Azolla filiculoides and Lemna gibba fighting it out for supremacy. The Azolla fronds arching upwards to cover the Lemna, and the Lemna becoming as gibbous as possible to prevent this.
They are seemingly resorting to fisticuffs.
September 21, 2025 at 11:18 AM
A wonderful Mint workshop with @ambroisebaker.bsky.social in Yorkshire. Some really interesting mint species and hybrids were seen.
M. x smithiana (aquatica x spicata x arvense).
With M. x verticillata (arvense x aquatica) nearby and long-gone M. spicata possibly from a nearby garden.
September 7, 2025 at 7:53 PM
Collecting seeds from Walter’s type location for Common Spike-rush (subsp. palustris), nearly 75 years since he made that first voucher. It felt like a momentous occasion.
Wakehurst Millenium Seed Bank visit by Stephanie Miles & Sarah Willard.
Many thanks Rob Dixon RSPB for facilitating the visit.
August 28, 2025 at 7:45 PM
I had the chance to visit Hatchet pond after work on Friday, choosing not to try driving to Herts until the M25 had calmed.
A pond that was well botanised, but also decided to take in the algae.
The inlet to the pond with a patchwork of fresh and decaying Zygnema species.
August 23, 2025 at 8:59 PM
Ivy-leaved Crowfoot (Ranunculus hederaceus) found today on the track in the Lymington Reedbed. A bare mud opportunity and not fussy about nutrient levels.
Just look at the size of the Greater Plantain (Plantago major) I found a short distance away! Must be on steroids or else well-fed and watered.
August 20, 2025 at 9:07 PM
Finally, in the New Forest I finally found Branched Bur-reed subspecies erectum! Everything else had been subspecies neglectum.
Told apart by the ripe seed shape. Subspecies neglectum has a gradually tapering apex to the nut. This has definite shoulders.
August 17, 2025 at 9:06 PM
Back to Hertfordshire for the weekend and dipped into the ponds at Purwell Ninesprings. It seemed the flow of water from the springs into the fens had been reversed, and the chalky nature reduced. Fen to bog danger!
One pond a sea of Common Stonewort (Chara vulgaris),
August 17, 2025 at 8:39 PM
I felt very privileged to find Hay-scented Buckler-fern (Dryopteris aemula) in a very humid valley on a very humid day in the New Forest. Triangular fronds, with crisped leaves and even the indusia had a pie crust edge.
August 17, 2025 at 8:17 PM
Out in the field again in the New Forest this week; amazed & excited by the plants & habitats.
So pleased to see Slender Marsh-bedstraw (Galium constrictum) which again was in a livestock-poached stream edge. A tall, strong specimen waving like a flag.
Pink-tingled buds.
August 17, 2025 at 7:56 PM
Out in the field again in the New Forest this week. Once again, I am blown away by the plant species and the freshwater habitats.
Here I found Square-stalked Willowherb (Epilobium tetragonum). A closer look revealed subsp. lamyi!
Found in a few places...
August 17, 2025 at 7:36 PM
Reposted by Dr Astrid Biddle
Low genetic diversity in populations of a clonal #invasiveplant limits sexual reproduction

New #AJB research by Ian Pearse, Zoe Becker, Paul Ode, John Gaskin & Natalie West

doi.org/10.1002/ajb2... #botany #plantscience #pollen #Brassicaceae
August 14, 2025 at 2:10 PM
OK for #PollinatorPals #WildflowerHour I have Rose Chafer (Cetonia aurata) completely blotto on Hemp agrimony (Eupatorium cannabinum). 😀
A beetle version of too many cream cakes!
August 10, 2025 at 7:12 PM
New Forest track rut erupting in a green covering of lettuce-like Fossombronia. Acid Frillwort (Fossombronia wondraczekii) determined using the spore ornamentation.
Amazing how the track ruts retain water even at this time of year!
August 9, 2025 at 4:12 PM
Three out of nine ponds I surveyed in the New Forest this week had the crazy-looking liverwort Riccia fluitans. Usually a floating species, it can also grow terrestrially. It seemed to thrive growing across decaying vegetation.
We really need some rain!
August 9, 2025 at 6:23 AM