Northants News 21.3

Welcome to this, the Autumn/Winter edition of Northants News, the magazine of the Northampton and Milton Keynes branch of the BCSS. Though printed for the November meeting is this still Autumn? Never mind…

At the same show was a class for two succulents. One exhibit included a leafy, lumpy sort of thing with the distinctive fruits of Pachypodium developing (I believe the posh name for these is follicles, perhaps our Colin (Walker) could tell us why.)

I picked it up to look for the species and noticed that the plant was grafted. The species was Pachypodium brevicaule. These also used to be available as imports from Madagascar. The plants resembled half buried potatoes with tufts of small leaves and if you were lucky you were treated to relatively large yellow flowers on short stems. That is until they died, when they just looked like rotten potatoes. Skilful growers could raise them from seed and with some winter warmth they grew into fine plants, though perhaps lacking the character of the imports. Now this grafted specimen was what we used to call ‘lush’. (What, we still do?) Large bright green leaves were sprouting in all directions.

grafted pachypodium brevicaule

The grower, Colin Graham, told me of his methods. He is generally successful in producing seed by hand pollination. Listen carefully. Cut a short length of 10lb nylon fishing line to a point with a sharp knife. Rough up the end with ‘wet and dry’ sandpaper. Probe gently towards the middle of flowers from different plants. This is best in the afternoon and on a warm day Wait... when ripe the seeds have parachutes like dandelions and may try to escape.

Colin grafts them as pea or match head size seedlings onto stocks of Pachypodium lamerei, a vigorous tree species also from Madagascar. He uses a surgeon’s scalpel for the cuts and the natural sap to stick scion to stock. These days he tells me he is grafting them onto pea size seedling lamerei. This obscures the two inches of stock that showed the plant on the show table was grafted. Whether judges will be able to gather from the vigour of growth that these are grafted is debatable. We sometimes see cacti which are just too good to be true!

Incidentally Pachypodium brevicaule was illustrated in the Alpine Garden Society’s Journal in an article on Madagascan plants. You hardly think of this as hardy!

I was visiting a neighbour’s garden and spotted a curious 4m high shrub. The plant was leafless and plastered with evil thorns. What drew my attention was the three lobed ‘fruits’. So… what on Earth is that? Have a guess!

puzzle plant?

The amateur (bad) botanist in me immediately said Euphorbia. Now Euphorbia is a huge genus ranging from annual garden weeds to trees. There are many succulent species which again include choice miniatures to large trees. The genus is characterised by three lobed fruit capsules which explode to distribute the seeds.

So Euphorbia something, except the label said Colletia paradoxa. Euphorbia family?

puzzle plant?

An internet search soon revealed that the plant was indeed a Colletia, a genus of five species from southern South America, and in the Rhamnaceae family. Not a Euphorbia and not remotely related.

Editorial and more..	Trevor Wray
Repotting Agave potatorum and more	Colin C Walker
Cacti and Succulents at Chelsea	Roland Tebbenham
Cacti on St. Lucia	David Kirkbright
Flowering Report - Astrophytums	Roland Tebbenham