Contents Volume 21. No 3

Winter 2010

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

Astrophytum capricorne flower

Cover picture: This striking image is a close-up view into a flower of Astrophytum capricorne taken by Roland. Astrophytums are rewarding cacti to grow with attractive bodies and large flowers. Since they bloom on new areoles they flower throughout the summer. You can read Roland’s entertaining article on the genus click here.


EDITORIAL and more.....


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…  

Well grown!

Some twenty years ago, or so, habitat plants of Euphorbia cylindrifolia were dug up in the wild in Madagascar and imported to Europe. We could imagine these stunted, natural bonsai eking out an existence on some wind-blasted, rocky hill at the mercy of the local goats. How old were these plants? Impossible to guess. But if I had to, then decades.

When I judged the Coventry branch evening show this June there were two in a class for one Euphorbia. Both were well grown and the larger was a stunner, if you like that sort of thing. It was fairly easy to award it a first.

While we enjoyed a cup of tea I asked the grower, Jeff Salisbury, if he had grown the plant for long. I was half wondering if they were still being imported from habitat. “Actually, I grew it from seed,” replied Jeff, and reaching for the label added, ”sown in 1999. I have several at home”. Apparently the secret is to keep them warm and watered in winter. So now we know, but they are not for the Wray cactorum, as I suspected.

Euphorbia cylindrifolia


Cultivating Pachypodium brevicaule

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!

What on Earth is that?

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.

Colletia hystrix

Colletia hystrix

 The main botanical interest is that these are nitrogen fixing plants like legumes. The fruits were in fact flower buds and the plant was in full bloom in October with small scented white flowers. Quite attractive but those thorns…

The internet indicated that Colletias are hardy only to -5ºC but this one was unscathed from much colder this last winter. There was also a doubt about the label. C. paradoxa has triangular thorns and C. hystrix from Chile is more robust with spine-like thorns. Whatever, a curious garden plant for those who like spikies.


F&W9596 Maihueniopsis

F & W what? My friend John from the Alpine Society buys ‘shares’ in seed collecting expeditions. An interesting way of acquiring novelties. This plant was grown from seed from a Watson trip to the Andes sown in 2002. The catalogue description says Maihueniopsis and I guess the species could be anything Opuntioid but probably ovata. It has not flowered yet. John gave it to me along with a Copiapoa coquimbana from this trip, an unlikely alpine!

The Maihueniopsis grows new globular joints every year with just a few rudimentary leaves. In the next year these joints grow spines and in the next glochids sprout. Then each year more glochids sprout until the lower joints are bristling with a formidable armament of them. Evil.

Everything in nature has a reason but I am not sure why this plant grows so many glochids. There may be a purpose for collecting dew. The usual pattern of cacti is to grow stronger spines each year which deter grazing animals. Interesting.

Maihueniopsis F&W 9596

Jeff Capel

Jeff Capel

On Jeff’s 70th birthday the 5th June, he entered the Spalding Show and came away with the Richard Carter Trophy for the Highest Points in the Mammillaria Group Classes. 

Hey, well done Jeff, a young 70 and a Mammillaria gong as well.

Ham squared.

I was repotting my plant labelled Hamatocactus hamatacanthus (what we old timers used to call Ham Squared) and thought I would give it an up to date posh label. When checking the spelling I found it in John Pilbeam’s Ferocactus book next to Ferocactus haematacanthus. Confusing this name game, and it gets worse. If you grow anything with the name Hamatocactus and want to show it be advised that H. hamatacanthus and H. sinuatus are in the Ferocactus Group but H. setispinus, H. uncinatus and H crassihamatus are in the Thelocactus Group. The last three are classified as Sclerocactus in the New Cactus Lexicon but they are still in the Thelocactus Group (at the moment!) not with Sclerocactus.



Next year we celebrate the 60th anniversary of our branch. Your committee are researching extravaganzas we might treat ourselves to. We are looking for ideas from branch members as well.

I see that Roland has put together a great programme of speakers again; some have not visited Northants Country before. Memo to self - must get the time off from work in many cases.

This magazine

Lots from our contributors. Just enjoy a gentle read.

Oh, and Happy Christmas.



Northampton and Milton Keynes Branch of the B.C.S.S.

Back issues of the NMK Branch magazine

Northants News Volume 21.2
Northants News Volume 21.1

Northants News Volume 20.3

Northants News Volume 20.2

Northants News Volume 20.1