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Archive for April, 2010

Dudleya Albums

Since ‘discovering’ Dudleya during a visit to California, in 2008, I have been baffled by their variability in habitat and the difficulty in deciding what species (singular or plural) that I’m seeing. I travelled along the Californian coastal area from Eureka, CA, close to the border with Oregon, down to the southern point of Baja.

Naturally I looked for an authoritative work in literature to help me. I learned that Reid Moran’s 1951 thesis ‘A Revision of Dudleya’ was still the respected reference work, but not readily available, although I now know at least one person with a photo copy of it. I was therefore very pleased to make an impulse purchase of the one and only published monograph of the Genus, or rather genera: The Dudleya and Hasseanthus Handbook. I was both pleased and disappointed as ultimately it has provided little help in identifying the Dudleya (and Hasseanthus) that I have seen and photographed since then.

I was however impressed with the total lack of pretence by the author that his book would solve all my problems of identification. I’ll quote the following from his ‘Nomenclatural Policy section:

‘… regardless of how accurate the descriptions or how good the color pictures it will be nearly impossible, with perhaps a very few exceptions, to POSITIVELY identify a plant. Many of the species have such a great deal of variation within them that at the extremes they might well be considered different species altogether.’

‘However, to further confuse the issue, the species hybridize in nature and tend to intergrade between one location and another, so even though the two extremes may be distinct species they may be connected by a series of intermediate forms leading to the possibility forms leading to to the possibly erroneous conclusion that they are all a single species.’  

How refreshing! Reading this section for the first time three years after I bought the book, I feel faced with the same dilemmas.  So why did the author carry on writing his book and why do I still refer to it? Mr Thompson died in 2009, so I can’t ask him that question. I refer to the book for its pictures of named Dudleya taxa from specific locations. Sometimes they help to put a name to a plant that I have photographed at that location. It’s a problem that I have also encountered in the Cactaceae as soon as I start taking anything more than a casual interest in a specific genus. There are more useful observations to be quoted:

‘ Even though plants grown in containers may differ from those found in the field this is not thought to be objectionable since the majority of collectors will probably be growing their plants in containers this making identification easier.’

WRONG! My need is to identify plants found in nature. But is does provide an interesting insight. If plants look markedly different in cultivation compared to those in nature, then this could indicate that the differences seen for these genera are largely influenced by environmental factors, rather than genetic ones.

It seems that the identification of Dudleya s.l. relies heavily on the characteristics of their inflorescence. It is therefore unfortunate that my observations are mainly from early Spring, February to early April, when most plants are not yet in flower and last year’s flower spike remnants have disappeared.

With these wisdoms in mind and numerous images of Dudleya in habitat as memories of past travels, I intend to post them here, mostly as ‘Dudleya sp.’ in the hope that people more experienced then I can suggest a name AND provide a reason why this is the correct name for these plants.

Fortunately I have found that at least some taxa, such as D. pachyphytum and D. (H.) blochmaniae ssp. brevifolia, are clearly distinct and that I have seen and photographed plants that match their description at the locations from where they have been cited. They each have an album included below.

In any event, I hope that you will agree that these albums show some wonderful plants, often growing in very photogenic settings and that despite the lack of botanical names, you will enjoy browsing through them.

DUDLEYA PACHYPHYTUM Moran & Benedict

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DUDLEYA BREVIFOLIA (Moran) Moran

s.n. D. blochmanniae (Eastwood) Moran ssp brevifolia (Moran) Moran

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Other photo albums are for plants at specific locations for which I’d welcome ID suggestions, particularly if it is possible to provide the rational for such suggestions.

THE DUDLEYA OF ISLA CEDROS

Various Internet resources list two species of Dudleya that are endemic to Isla Cedros: Dudleya pachyphytum and Dudleya cedrosensis. Some of the Internet resources report that the name D. cedrosensis is invalid. Detailed searches for images of the illusive D. cedrosensis failed to produce results. So what were the Dudleya, other than the relatively easy to ID D. pachyphytum, that we saw during our three days plus stay on the island?

The variable D. albiflora has been reported from the island and we saw some plants that might be this species

Are these that Species?

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There was a very distinct plant that grew forming large clumps, but seemed to be very limited in distribution. Could this be D. cedrosensis nom. inval.? Is it even a Dudleya? No buds, flowers or remains seen

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And what name should we use for this plant? Could it be a hybrid, with D. pachyphytum as one of the parents? So D. pachyphytum x X?

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Future entries

As usual, by the time that I get home from a cactus trip, the next one is already planned. This time is no exception, with Angie and I, joined by David Neville flying out to Santiago, Chile on Friday 8 October 2010. Until then, I have no plans for regular updates to the blog.

Post scripts: 11 April 2010

On this day, we drove along Carretera Federal 16 from Chihuahua to Yecova in Sonora, commenting that we were stopped at four army checkpoints that day. We were unaware at the time that two days earlier, another town along that road, that we had driven through, had been ‘held hostage’ by gunmen.

From the Latin American Herald Tribune:

‘MEXICO CITY – Dozens of organized crime gunmen stormed a small town in the northwestern Mexican state of Sonora, killing four people and setting a police headquarters ablaze, state Attorney General Abel Murrieta said.

The assailants burst into the town of Maycoba at around 6:00 p.m. Thursday and stayed about five hours, according to local residents.
Between 80 and 100 gunmen bearing rifles and with their faces covered entered the town on board about 15 late-model vehicles, Murrieta told a press conference on Friday.

Their first action was to open fire on the town’s police station and then set it on fire. The police in the small town were not at the station at the time of the attack and were therefore unharmed, the prosecutor said.

But the gunmen killed the father of the local police chief and three dead bodies were found a few kilometers from the town, two of whom have still not been identified. They also looted a store.

Prior to terrorizing the town, the group of gunmen had blockaded the nearby federal highway with two trucks.’

Post scripts: S1691, 7 February 2010: Las Tunas, Cuba

Regular readers may remember the images of an Anole lizard sp. feeding on the nectar of a Euphorbia sp. that we saw widespread throughout Cuba, often used as fencing. During my visit to California in March, Petra Crist of the ‘Rare Succulents’ nursery in Rainbow, told me that this was Euphorbia graniticola, and further searching under this name on Google reveals that it is a native of Mozambique.

How did it get to Cuba? It certainly likes the conditions here and the Cubans seem to have turned this to good advantage by using it to produce self-maintaining fences.

Thank you, Petra, for the information.

Thursday, 15 April, 2010 – flight home continued

Around 6:30 a.m. we had crossed the Irish Sea and were flying over North Wales, just as Angie was setting off from Amesbury to meet me at Heathrow. She was travelling at around 70 mph. while our plane monitor told me that we were doing 500 mph. It took exactly 30 minutes from the plane landing for me to find a seat near the Costa coffee shop to wait for Angie, slowed down by rush hour traffic, to arrive.

As we approached Heathrow, the pilot announced that passengers transferring to other flights at Heathrow should contact their airline information desks as there was a threat of flight cancellations due to a cloud of ash drifting from Iceland to the UK. It looks as if I had left taken a later flight from LA, it might well have been cancelled or diverted, so a lucky escape!

From the BBC News website:

Airline passengers are facing massive disruption across the UK after an ash cloud from a volcanic eruption in Iceland grounded planes.

The Air Traffic Control Service (Nats) said no flights would be allowed in or out of UK airspace from midday to 1800BST amid fears of engine damage.

The restrictions were imposed after the Met Office warned the ash was sufficient to clog engines. Passengers were also affected in Norway, Sweden, Finland and Denmark. Passengers were advised to contact their carriers prior to travel.

Experts have warned that the tiny particles of rock, glass and sand contained in the ash cloud would be sufficient to jam aircraft engines …..

Wednesday, 14 April, 2010 – Bellflower, CA to LAX and flight home

One of the smoothest departures for homeward bound journeys that I can remember: up at 6, MSN chat with Angie, a quick repack as always, then, by 9 a casual drive from Bellflower via a coffee shop for a light breakfast on to LAX. Check in desks here have been replaced by electronic check in machines at each counter, with a member of staff only appearing once you have completed all the questions and the machine has printed your boarding ticket. Their task is limited to checking the weight of the luggage, sticking on the appropriate stickers and moving the luggage on its way to the plane.

The plane left right on schedule at 12:45 in the afternoon and after a light lunch I settled down for 10 hours or so of snoozing.

Tuesday, 13 April, 2010 – Tucson, AZ to Bellflower, CA

Today was all about covering the c. 440 miles (we left kilometres behind in Mexico), so the only stops were leg stretchers and toilet stops and not plant stops. At one such stop, at Desert Centre, CA we spotted some very affordable Native American textile souvenirs, that were quickly picked up, as bags and purses are always useful. Back on the road, closer inspection of labels revealed that they were indeed Indian produce, but the country in Asia, rather than the Red Indian nation. Never mind

We left Tucson at 6:30 and had lunch around 8 near the place where I-10 splits into the I-8 and I-10. We took the 10, passed Phoenix, crossed into California at Blyth, drove between snow capped mountains before passing Palm Springs and then started battling with increased volumes of traffic indicating that be must be approaching Bellflower.

Arrived safely around 4, got the car cleaned by 5, returned it by 6 (very smooth; they were very busy), went shopping at Fry’s for hard drives, then for the almost traditional Chinese meal at Ming’s (more than we could eat as usual) and now doing panic repack while downloading each others pictures.