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To the Bridge of God and BeyondAuthor(s): John PilbeamSource: Cactus and Succulent Journal, 84(6):294-297. 2012.Published By: Cactus and Succulent Society of AmericaDOI: http://dx.doi.org/10.2985/0007-9367-84.6.294URL: http://www.bioone.org/doi/full/10.2985/0007-9367-84.6.294

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294 CaCtus and suCCulent Journal

To the Bridge of God and Beyond

I’ve always found a little worrying the amal-gamation as a variety of Echeveria halbingeri what was originally described as Echeveria sanchez-mejoradae by Eric Walther in 1972 in his almost biblical work as far as this genus is concerned. The two make some-what different looking leaves and rosettes,

and have differing chromosome counts (62 for the type, var. halbingeri, and 32 for var. sanchez-mejoradae). But my main concern has been the complete difference in the flowers of these two, with orange, strongly recurv-ing petal-tips in the type (Fig. 1), and the distinctly reddish-pink petals with yellow to green petal-tips only slightly recurving of var. sanchez-mejoradae (Fig. 2). But maybe this does not carry the significance that I tend to see in it. Be that as it may they are both delight-ful plants to grow in cultivation, with attractive, neat rosettes, and a tidy, low-growing, slowly clustering habit, crowned by shepherd’s crook spikes of flowers in the spring or early summer.

It was therefore with interest that I read of a precise location for E. halbingeri var. sanchez-mejoradae in an area we were planning to pass nearby on a trip in 2010 from Oaxaca through Puebla to Hidalgo. And so I managed to persuade the other members of the party (Derek Bowdery and David Neville from the UK, and Jim Peck and Mary McLenahan, our ex-pat Canadian friends domiciled in southern Mexico), to take a look for this variety on our planned trip to the area. They did not need much convincing, as any side road will usually reveal more than enough of interest to make a diversion worthwhile, and most of the party were as keen as I was on finding Echeverias we had not hitherto seen.

We spent our first night in Atotonilco El Grande, a town north of the capital Pachuca in Hidalgo shiver-ing in bed in a hotel with few facilities, with the rain pouring down outside, to the extent that on an evening trip to find a nearby eating place I felt I should have brought a thick jumper, a mackintosh and an umbrella. Not a good start, and with the hope that surely the weather must improve we set out the next day with this and other succulent prey in mind, to wit Mammillaria amajacensis, reported from the Puente de Dios, in Hidalgo state. I had promised Keith Flanagan, an English Mammillaria enthusiast with one of the best

collections of this genus I have seen, to try to find this species, as on previous trips to this state he had failed

JoHn PiLbeaM

1. the inflorescence of Echeveria halbingeri var. hal-bingeri, clonotype plant.

2. the flowers of Echeveria halbingeri var. sanchez-mejoradae on a plant from close to the type locality.

2012 volume 84 number 6 295

to persuade his companions to pursue its whereabouts.My companions were persuaded that it was worth

a try, and we spotted the turn off the main road we needed soon after leaving the previous chilly night behind us. The weather had improved, and we made good progress along this road leading to nowhere par-ticular it seemed, and with no such place as the Puente de Dios marked on our maps we knew not how far we should go. The name translates as ‘Bridge of God’, so we were expecting some sort of natural structure resem-bling a bridge. After some considerable distance with a few Mammillaria-fruitless stops, we spotted some goats and a goatherd in the form of a teenager, dressed for

comfort from the sun in a red hooded coat (Fig. 3). At this point the road crossed from one small mountain slope to another with a drop either side (Fig. 4). Could this be the Bridge of God we wondered, and stopped and put the question to the lad.

He confirmed that it was, and further that the plants we described to him were now very rare as many visitors had come to this spot in the past and taken them away. In an hour or so’s scouting by all of us only a few were indeed discovered and photographed, unfortunately not in flower but clearly the species in question (Fig. 5). In the New Cactus Lexicon it is referred arbitrarily to synonymy with M. orcuttii, but I do not buy this at all,

4. Looking down from the bridge of God. 5. Mammillaria amajacensis in habitat and (ML 46, inset) cultivation.

3. the red-hooded goatherd on the other side of the road over the bridge of God.

296 CaCtus and suCCulent Journal

having grown both and seen both in habitat, over 200 km distant from each other, with no reports between.

On then, after this longer-than-expected digression to our next target, again off on a side road, which we located without much difficulty. Mile after slowly mile we scanned the sides of the road and saw not a sign of an Echeveria, although there were several likely shady stretches, and the occasional stop yielded nothing much else either.

The feeling had crept upon me that we were on

the wrong road, as the photograph I had used in my Echeveria book was taken by Chris Davies allegedly by this roadside. Could I have got it wrong? Quite easily I thought, my heart sinking at the expected chi-iking that I would get when we got to the end of the road, which we were rapidly approaching. But then suddenly there they were, as expected on a near-sheer, shady, rocky bank in leaf litter, and it was smiles all round as we photographed the short-stemmed, neat rosettes growing lustily, mostly solitary, with regeneration in

6. Echeveria halbingeri var. sanchez-mejoradae in abundance.

7. Good drainage and maybe not too much sun are indicated for this Echeveria on its sheer, shady slabs of rock.

2012 volume 84 number 6 297

the form of small seedlings in evidence. (Figs. 6 & 7) If we had sneezed at this point of the journey we might well have missed seeing them, as they occupied only about a 20 or 30 metre stretch by the road. They may have occurred in the nearby hillsides, but these were not easily acces-sible, and since they were there by the side of the road we settled for that. One thing immediately struck me, and that was that what is widespread in Europe in Echeveria collections under the name of the variety is not the same, with paler green leaves with no hint of blue, and a very vigorous clustering habit, betraying perhaps hybrid origins.

What I need to do now I realize, is to go again to southern Hidalgo, but this time take the road to Actopan, near which E. halbingeri var. halbingeri grows, to con-firm what is there and what maybe lies between the two varieties. Certainly com-paring the two in cultivation (Figs. 8 & 9) still leaves me in doubt as to their rela-tionship. Am I worrying unduly Myron?

9. Echeveria halbingeri var. halbingeri (clonotype) in cultivation.

8. Close up to Echeveria halbingeri var. sanchez-mejoradae in habitat, close to type locality.