Northants News 16.2 Summer 2005

The monstrous Lophocereus

Doug Rowland

Trevor has asked me to do a piece on Lophocereus schottii v monstrosus, which is a very interesting and quite uncommon plant in collections. However, to make a job of it I will start at the beginning with the species.

Lophocereus schottii (Engelmann) Britton and Rose.

This species was described by Engelmann in 1856, as Cereus schottii, later to be placed in the genus Lophocereus by Britton and Rose in 1909. Today it is generally recognised as Pachycereus schottii Hunt 1987. In the United States and Mexico it is known as the Senita Cactus. (Senita = ‘old one’ in Spanish after the grey bristles.) This is a very distinctive species and easy to recognise, the tall stems being covered in sharp needle like grey spines towards their uppermost parts. The species is nocturnal flowering and is of easy cultivation.

The plants tend to grow in colonies in favourable locations in dry gravelly soils. They enjoy warmth and the most northerly stands in Southern Arizona are smaller in size than their more southerly counterparts.

The tall stems branch from the base and eventually form clumps 6’ to 21’ tall and are 4½” to 5” in diameter. The stems as they mature become more spiny above than below. Flowers and fruits eventually emerge from these more spiny areas. Occasionally the ends of stems will spiral a little or dramatically in a right or left hand manner Such top cuttings are much prized by Californian enthusiasts, fetching high prices. A spiny tip taken into cultivation will root satisfactorily, but will not grow, throwing out a single juvenile offset in time. On mature plants the flowers are greenish white on the underside and pinkish white inside and emit an unpleasant odour. One or several flowers are produced from each areole. The flowers open at dusk and continue until early morning when the sun burns them out, allowing a little photographic opportunity for early desert risers. The fruits are as red as ripe strawberries and are seldom seen, as they are quickly taken by hungry desert birds.

There are three locations where this plant can be found. In Pima County in the south of Arizona along the Mexican border, this species is at the northern limit of its range and perhaps there are only around 50 plants here, which are on the smaller side. Colonies further south in Sonora do progressively better. It is also fairly common in Baja California down to the Cape district. Plants will also do well in cultivation in the open in Tucson and Phoenix in Arizona.

This species presents no problems in cultivation and will do well in a sunny spot in a cactus house in a gritty soil mix. Seeds are plentiful in commerce and many enthusiasts buy and sow these in the hope that a monstrose seedling will appear.

Lophocereus schottii

Lophocereus schottii still in flower at dawn in the Organ Pipe National Monument, Arizona.

Lophocereus schottii f. monstrosus Lindsay.

This is a very interesting, easy and slow growing fasciated form of Lophocereus schottii. It is also known as Lophocereus schottii f. mieckleyanus. The northern part of Baja California, Mexico is noted for the several kinds of cristate Cactaceae which can be found there often quite close to the main coast road down from Tijuana. Ferocactus gracilis, Machaereocereus gummosus, Echinocereus brandeegii, Pachycereus pringlei and Mammillaria can all be found there.

Lophocereus schottii f. monstrosus in habitat

Monstrous Lophocereus schottii in habitat in Baja California, Mexico.

In 1931 the American botanist and explorer Howard Gates was travelling down the Baja peninsula on unmade dirt roads and came across a colony of strange monstrose plants growing in a very soft sandy and gravelly soil. As this monstrose form of Lophocereus schottii does not apparently flower or seed, all specimens also in cultivation must have at one time been propagated vegatively, unless a species plant now and again yielded a fasciated seedling.

The stems are slim, lightly pruinose with broad rounded protuberances roughly branched and poorly defined. The areoles are few and insignificant and flowers and seeds virtually unknown. Stems are ascending and branching, occasionally at higher levels reverting to normal species growths. However I have not observed the cluster of hard grey needle like down pointing spines that occur on species plants at stem ends.

In habitat and cultivated specimens, the stems mark quite badly in age due to blowing sand, weathering and old age. Usually, only a few inches of growing stems remain in pristine condition. As we do not live in a perfect world this form is not recommended for growing on as a show plant.

The habitat of this plant is a fairly small area NE of El Arco, about halfway down the Baja peninsula. Plants there are heavily weathered and badly marked with just the newest growing tips being in good condition. The plants are in quantity and grow together in small thickets allowing one to walk amongst them freely, but with each step sinking a little into the soft sandy soil.

Fortunately this plant cultivates well but grows on rather slowly. It also branches, just from the base, which the species does not. The monstrose plants enjoy a warm sunny environment and for more speedy growth a light position on a higher shelf with light feeding and rainwater given to the bottom of the plant will ensure success, especially with rooted detached branches, which do well in these conditions. I had a plant which grew almost 6” like this last year.

Even plants in cultivation will begin to get a bit tatty after some years, and if you wrap an offset in newspaper and send it to your friend through the post, it will probably mark anyway, so you can’t win. It is now essential for us to grow and propagate this interesting plant for none will ever be forthcoming other than from our own collections. A 3” long tip or branch is most suitable for propagation. Allow to dry off and root in spring in gentle heat and being very careful with the watering for a start, using a gritty compost. Often plants can be seen with a root or two projecting from a lower stem.

Some enthusiasts often sow seeds of Lophocereus schottii in the hope that a monstrose seedling will occur amongst the progeny.

These monstrose plants cultivate well outside in Phoenix and Tucson. In Tucson, some of the nursery stock growing outside had stayed monstrose for about six feet of its height and then reverted to normal smaller growth of the species. Some stems reached 20 feet.

I visited the author W Hubert Earl in 1982 in Phoenix, Arizona, who lived under Camelback Mountain. He showed me a whole row of Lophocereus schottii f. monstrosus that were growing in a long line across his garden. Some had had their branches and tips removed but all were growing well. He said that cactus nuts from all over visited him to buy cuttings of all sizes taken from these plants, which he sold by the foot run to help pay his taxes.

Finally, the greatest problem that you will ever have with this very interesting plant will be finding one to buy in the first place.


Lophocereus schottii f. monstrosus for sale Well the Ed was lucky – not only was he able to get to the National Show last year but there were some rooted cuttings for sale there of Lophocereus schottii f. monstrosus at a mere £4. The picture (left) of a plant for sale was taken at the Colorado C&SS sale at Denver. Doug wrote that the form grew well in Phoenix and one of NN resident reporters has a few yards of it outside his front door (pictured right). The bougainvillea was pretty good too! I think I’ll have to move to this Phoenix place.

Lophocereus schottii f. monstrosus in a Phoenix garden


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