From the Baja peninsula Mexico comes a very interesting cactus believed to be a natural hybrid whose parents is thought to have come from Mytillocactus cochal and Bergerocactus emoryi (fig. 1). Both of these cacti grow wild in the area where the plant was found. First noticed by a hunter, he lead botanist George Lindsay to where the cactus was growing some fifteen years later in 1950 located about 8 miles south of El Rosario, Baja California and one mile inland from Rosario bay. Closely studied by botanist Reid Moran he named it Myrtgerocactus, (1962) the name containing parts both of Myrtillocactus and Bergerocactus and lindsayi after George Lindsay the botanist given credit for its discovery.
For decades only one had been found and some botanists even thought it to be a lone survivor possibly a second specie of Bergerocactus but careful comparisons of Myrtgerocactus and the possible parents pointed more towards it being a natural hybrid (Fig. 2). Over the years some cuttings of the original habitat plant were distributed to certain public botanical gardens and a few nurseries so it is possible but uncommon to find them for sale. In recent years there are reports of one or two more myrtgerocactus plants being found from explorations of a botanist exploring Baja California but I have not been able to verify this.
I bought my myrtgerocactus in 1995 at Muellers cactus nursery in Bakersfield, California shortly before they closed their doors for good a couple years later. I believe the Muellers started the nursery in the early 1970s. After their passing in a car accident the new owners had the nursery until around 1997. I suspect the myrtgerocactus had been sitting there for decades mostly unknown by average cactus collectors and ignored. Very little literature can be found on the plant and considering the plant's rarity especially up until around 1998 its no wonder why very few are familiar with it. I have only seen one small color photo published of the plant. After 1998 I started distributing a few cuttings and one or two years later noticed one old and large retail C&S nursery offering rooted plants too. I believe people reading the label at Muellers nursery generally thought it to be some kind of myrtillocactus as I did for a minute and decided not to pay the hefty price they were asking for it. Actually all their cacti were in the high price range because most were more or less specimen plants with very few or no small plants to be found in the whole nursery. In my travels I have encountered specimens of Myrtgerocactus at a couple of public botanical gardens, one very old private collection, one extensive new private collection (name was not confirmed) and two cactus and succulent nurseries, one of which is where I bought my plant.
Myrtgerocactus lindsayi has been observed to reach up to nearly 2.5 meters high in habitat (fig. 3). It is more or less a "columnar type" cactus but weakly so. "Grows like a bush" would probably be a more accurate way to describe how this cactus grows because it branches both from the base and higher up while Myrtillocactus have been described as growing "tree like" because of their short trunk. My plant is now two meters in height and except for the lack of a short trunk wants to grow similar to a myrtillocactus, branching and rebranching into a wide tree. I had to tie my plant to many stakes pushed far down into the soil of its large pot to keep it from taking up too much of the space in the greenhouse. Tied the total width of the plant is about 3 feet. Not tied it would be approximately five to six feet wide by now.
It is a fairly fast growing cactus and the columns display a pretty bluish green color. Some stalks grew a foot or more in a growing season. My original plant and other plants started from cuttings branched only from the base at first. When the columns reached a few feet high they started more columns from near the base and also branching from the existing columns higher up similar to but not as much as myrtillocactus species. The extra weight of the new branches higher up make the columns start leaning and widening. Columns measured 4 cm thick and more on old original columns and up to 5.5 cm thick on some of the new stalks. Rib count on my large plant varied with the eleven stalks I counted. Rib counts on old original stalks were 11 and 12. Ribs on new stalks since I owned the plant were 14,15,15,15,15,12,13,13,13. Rib width on my plants measured from 5 to 8 mm with 6 and 7 mm most common. Rib depth measured 4 to 6 mm.
Areoles are more or less round measuring 4 and 5 mm. Color of new areoles are tan or beige at first and turning white later. Areole spacing varied a lot from 10 mm to 18 mm apart from center to center. Two to 4 central spines are usually noticed per areole but fairly hard to differentiate from the radials. Central spines 2 to 2.5 cm long are common but some were longer and up to 3.7 cm long near the apex, no doubt the full sun exposure I give the plant helped here. I counted from 18 to 24 radial spines per areole. Spines are a mixture of yellow and brown a pretty contrast with the plants bluish green epidermis (fig. 4). On some well-aged stalks the spines can even turn black.
My Myrtgerocactus flowers randomly anywhere on the top half of the plant. One flower per areole, never two per areole like often seen with myrtillocactus species. It produces hundreds of flowers each year from spring until fall. Flowers when first opening are yellowish green but then turning greenish yellow. Flowers are diurnal (opening in the day) and even overcast days. The length of the flowers when first starting to open are at there longest and measured from 4 to 5 cm. Size of expansion varied and measured a minimum of 3 cm wide and a maximum of 4.5 cm wide (fig. 5). Flowers fully open vary in length from 3 to 4 cm long and remained open for one full day. Myrtgerocactus flowers have been reported to have a mild fragrance but I smelled little or nothing.
Because the greenhouse top is removed the cactus is outside throughout the growing season and a wide variety of Bees visit the flowers. Hummingbirds are also constantly hovering nearby. With all this activity the fruits swell up and turn crimson to purple but it is a pity that none of the many I checked contained any seeds and have never been reported to contain any (fig. 6). Pulp is usually not present in the fruits that I cut in half. One fruit I examined that seemed riper contained some pulp that was carmine slightly lighter in color than the fruit epidermis but still no seeds were found. One good-sized fruit I selected randomly measured 14 mm long and 11.5 mm wide. It is interesting to note the small fruit size close to Myrtillocactus as compared with quite large fruits of Bergerocactus. The fruits are very spiny (similar to Bergerocactus fruits) with persistent floral remains and one must be careful when picking them off when dried up so as not to get stuck like I have been. Fruits are indehiscent (not splitting open at maturity). They quickly dry up shrinking in size down to nothing so that all that remains is a bunch of spines on a dead floral tube disconnected from the areole but held in place by the intermingling of these spines and the areolar spines.
Myrtgerocactus is easy to grow in cultivation and can even be recommended for beginners. I have started cuttings in a variety of soil contents with good results each time. My plant is in a 20 in. deep by 16 in. wide pot. The soil is made up of peat with some perlite added, a soil I no longer use. This cactus seems to prefer average to above average amounts of water during the growing season.
Backeberg, C. 1976.3rd ed. Cactus Lexicon: 320. Blandford Press, Poole, Dorset, England.
Moran, R.1962 "The Unique Cereus of Rosario Bay", Cactus and Succulent Journal Vol. XXXIV, No. 6. Nov.-Dec. Allen Press, Inc. Lawrence, KS.
Copyright Bob Ressler, no reproduction without permission of the author.