Silwoodians. This is what the interior of CPB looks like today. All of the interior walls on thr Hamilton side of the building are gone. Just 1 big space now. GIS lab, common room, labs and computing room all gone .

Telling Aphanes arvensis (left) from A. australis (right) is all about the teeth at the tip of the calyx (x20). If the teeth are spreading, so the flower looks star-shaped from above, you have arvensis. If the teeth are upright (so the flower is barrel-shaped) that's australis.

My advice is that if you really want to get into identifying grasses, sedges and rushes properly, then your best bet is to purchase a 3-D dissecting microscope (left) and fibre optic lights (right). There is plenty of choice on Ebay, but it's true that new kit is very expensive.

Prunus avium 'Plena' is gorgeous pure, snowy white for about 10 days. Then, regrettably, it enters what we call the 'Used Tea Bag' phase, which lasts a lot longer and looks extremely unappealing (below). We need to breed a self-dead-heading genotype. That would be a real winner.

In studies of the flowering phenology of Japanese Cherries these two mark the middle of the 'Mid' season. Prunus 'Kanzan' (left) flowers just before P. avium 'Plena'. Things like P. x yedoensis and P. 'Shirotate' are distant memories now.

Save Shirley Heath and Addington (Shirley) Hills - sign the petition! Thank you Inside Croydon for highlighting this appalling proposal and Peter Underwood (He/Him) 💚 for starting the petition. chng.it/gwWCcHSK via Change.org UK

Silwoodians. This is what the ground floor of Munro looks like this morning. The 1987 vintage offices and labs have been stripped out to make way for a modern, open-plan lab space. On the left, you see Kennedy Building through the window, and Hamilton on the right.

Another bit of Silwood history gone. The American wartime concrete prefab which was moved to Silwood from Sunninghill Park before 1947 served for many years as our Stores building, where you went to get test tubes, chemicals and stationery from Ena and her colleagues.

Order of flowering. Another one for you to help me with. Where you live, does Prunus 'Shirotae' (pure white, droopy, left) flower before P. 'Tai-haku' (pink eye, patent, right). At Silwood, P. 'Shirotae' is 6 days earlier.

It's Viburnum sniffing time. The plant with glossy upper leaves is V. x burkwoodii (left) and with dull upper leaves is most likely to be V. carlesii (right). Don't just walk by; stop and have a proper deep sniff. You won't regret it.

I'm working on a list of flowering order. You can help with this by telling me which flowers first with you and by how many days: Prunus 'Accolade' (left) or 'Pandora' (right). Frilly and drooping, or entire and patent. At Silwood 'Accolade' is first by 7 days.

This is the wonderful Butia odorata in Chumleigh Gardens, Burgess Park (TQ3310 7779) in Camberwell, London.

If you thought that Narcissus 'Telamonius Plenus' was ugly, then how about this one? It's Narcissus 'Thomas' Virescent Daffodil' . Its synonym is Narcissus 'The Derwydd Daffodil'.