Two stars for me are my first ever sightings of the Myriophyllum genus. I found Myriophyllum alternifolium in a lovely clear stream up near the Brecon Beacons Visitor Centre:
Myriophyllum alterniflorum, Alternate Water-milfoil
Nearby was a plant that stumped me for quite a while - a Charophyte - one of the really quite vascular-plant-like ones:
Chara virgata, Delicate Stonewort
The other Myriophyllum was occupying a casual pool in a limestone quarry near the southern Breconshire border:
Myriophyllum spicatum, Spiked Water-milfoil
And, for something completely different...
Nectaroscordum siculum, Honey Garlic
A garden escape but well established and spreading on the old railway line path in Hay.