HOOCK, H. 1990 . Kaktus (Nordisk Kaktus Selskab) Band: 25 Heft (3) Seite 51-54 Pa jagt efter Astrophytum i Bolson de Cuatro Cienegas (Auf Astrophytensuche im Bolson de Cuatro Cienegas)


On Search for Astrophytums in the Bolson de Cuatro Cienegas

Next to the stone steppes (1) the closed geological basin formations belong to the most impressive views of the Chihuahua desert. They are formed by mountain ranges which enclose levels and valleys in a form that a natural water drain isn't possible. Therefore in Mexico one calls them characteristic "bolson" what means bag or pocket. In these closed areas usually arid regions predominate but also smaller marsh fields and lagoons arise. Sometimes a completely independent, endemic fauna and flora develops in such ecological niches. The Bolson de Cuatro Cienegas is particularly famous in north Coahuila for it. It approximately contains an area of 500 square kilometres and is surrounded by the mountains of the Sierra Anteojo, Ovejas, Purisima, San Marcos and La Fragua, which tower above 2000 metres (2) from the bolson with 600 metres over sea level. The Sierra of San Marco almost divides the Bolson into north-south direction completely. On its northern end, at a few kilometres broad, flat connecting part between the eastern and western basin, the little town Cuatro Cienegas (3) is located. This was my starting point for a search of Astrophytum capricorne v. niveum (KAYSER) OKUMURA several days in December 1985.

Astrophytum capricorne v. niveum was already discovered in 1930 by W. VIERECK in this area, few years later described as Echinocactus capricornis v. niveus (4) by K. KAYSER as a new variety and cultivated as a special rarity in European special collections. It differs from the since 1851 known Astrophytum capricorne (DIETRICH) BRITTON & ROSE primarily by very strong, edged spines. The body is covered with thick white fluffy flakes at free locations. Unlike the normal Capricorne the flakes are also pure white in the new shoot of the plants while the first ones have brown flakes at the top. After a spherical youth stage Astrophytum capricorne v. niveum grows to short, solid columns which reach a diameter up to 20 cm at a height of about 50 cm. Their yellow flowers with a red till orange colour throat and up to 9 cm of diameters do not develop stamen-hairs in the nectar chamber. One seldom also find pure yellow flowering Niveums at the habitat. Therefore one can assume that the plants are mixed inherited at the location regarding her flower throat colour.

Astrophytum capricorne v. niveum isn't only rare in our greenhouses, it was never frequently represented in the Bolson de Cuatro Cienegas, too . By unprincipled collectors it was decimated strongly moreover within the last few years so that it belongs to the particularly endangered cacti today. At first I found only very isolated and in large separations smaller plants at the foothills of the Sierra Anteojo, at "wintry" temperatures around 30 degrees in the shade. After an almost unsuccessful and exhausting day, I returned a little disappointed to the way to Cuatro Cienegas. At the way down by a flat rubble field, without paying attention to Astrophytum still further, I discovered by chance an intact Niveum family on less than 100 square metres (diagram).

The complete group of this beautiful Astrophytum capricorne v. niveum population contains about 20-25 plants, partly growing close together, partly scattered, from little baby plants with only 5 cm in diameter to tall columns up to 40 cm height. Almost all individuals grow free in the lime rubble, whose grey colour fits perfect mimetic to the dense flaked plants. Even on the shortest distance one can hardly differ the plants from the child head large rocks around. The stong, grey spines of the Astrophytums look like arid tufts of grass so that the optical deception is still increased.

At most locations of the Astrophytums one can state, that seedlings and young plants survive the extreme climate conditions within the first years by the protection of foster mother plants. Its are mainly Hechtias and Larrea shrubs in the south at the locations of Astrophytum myriostigma LEMAIRE, and Agave lechuguilla TORREY in the habitats of Astrophytum capricorne which offer the necessary shadow against the burning heat. At the described Niveum group this protection function is partly realized by the loosely lying gravel of the pre-mountains. However, single plants are found on the margin of the area in community with Larrea DE CANDOLLE (form 1) (5) and Mesquite (form 2) (6). The group with four plants grew up under protection of Grusonia bradtiana (Syn. Opuntia bradtiana) (COULTER) BRITTON & ROSE and Echinocereus stramineus (ENGELMANN) RÜMPLER. However, the semicircular order also would suggest that this form comes from a died Agave lechuguilla collection. These succulents form frequently metre large islands whose middle ring then widens by faded, died plants.

The more correct examination of single Niveums brought surprising results. It has to be actually expected that the rib number with the age of the Astrophytums increases. Of all population members, however, only a smaller plant has 9 ribs (number 1 in the diagram), while even the largest specimen remained on the conservative number 8 (number 9 in the diagram). The age of this imposing Astrophytum capricorne v. niveum can be estimated only approximate by far more than 50 years. In the upper quarter of his dense spine covered body it owns, not on the rib but beside, a lonely areole. A surely very rare phenomenon (figure 3).

At the top of most Niveums were many, dry, unpollinated flowers but also emptied fruits. In two cases older seed capsules were found with, how later proved, shoot incompetent seed. Both fruits still were closed. Had these ubiquitous ants not discovered the smell of the ripe fruits and not fulfilled therefore her function to the myrmecochorie (seed dispersal by ants) (7) here? Or is at Astrophytum capricorne v. niveum also another seed distribution mechanisms by birds or mammals of importance, how one could suspect by the red colouring of ripe fruits? I watched at all events a deep brown squirrel and a lime grey rabbit in closer distance of the location, both animals to be believed capable the consumption of Astrophytum fruits.

The flora of nearby surroundings of this Niveum family is stamped by large-area Grusonia bradtiana populations, half-height Larrea bushes and the Mesquite shrub. Turquoise green yucca groups (8) isolatedly rise about this, in this season's leafless crops of Fouquieria splendens ENGELMANN (9) and metres high inflorescences of stemless Dasylirion ZUCCARINI (10). The region up to approximately knee height is dominated by Agave lechuguilla, grasses, as well as Euphorbia antisyphilitica ZUCCARINI. Very beautiful specimens of cacti were found like: Ariocarpus fissuratus (ENGELMANN) SCHUMANN, Lophophora williamsii (LEMAIRE ex SALM DYCK) COULTER, Echinocereus pectinatus v. rigidissimus (Syn. E. rigidissimus v. rigidissimus) (ENGELMANN) RÜMPLER, Epithelantha micromeris (ENGELMANN) WEBER, Echinocactus horizonthalonius LEMAIRE and Mammillaria leona (Syn. M. pottsii) POSELGER. They develop under the UV rich light in the Bolson an outfit which culture conditions can not reach. Echinocereus stramineus has so long spines here, that the plant body can be hardly seen.

At the output of the basin in west direction there exists another Astrophytum population with flake reduction (11). Thick and thin flaked individuals find themselves there at the same location next to pure green plants in an immediate neighbourhood (figure 4). This high evolved form of Astrophytum capricorne v. niveum is presumably the geographical starting point for the further to the south growing naked, yellow spined Astrophytum capricorne v. aureum MÖLLER. Few months after my visit European cactus dealers and tourists looted the Astrophytum habitat at this remote basin part. It was then set on fire by a campfire deliberately or inadvertently. It remains only hope that the beautiful Niveum group at the foothills of the Sierra Anteojo isn't discovered by such vandals and survives undisturbed in the silence of the Bolson de Cuatro Cienegas still for a long time.

Literature:
BERNHARD, U.; HOOCK, H. (1986): Die Astrophyten von Cuatro Cienegas, Kakt. and. Sukk. 37 (7): 141-147

BOKE, N. H. (1968): Excursiones de la Universidad de Oklahoma en el Norte de Mexico - 1967, Cact. Suc. Mex. 13 (3): 50-58

BROWN, D. E. (1982): Chihuahuan Desertscrub, Desert Plants 4 (1/4): 169-179

HOOCK, H. (1986): Die Mimese der Astrophyten, Kakt. and. Sukk. 37 (10): 208-211

HOOCK, H. (1988): Schutz der Nektarkammer bei Astrophytum-Blüten, Kakt. and. Sukk., 39 (3): 58-61

KAYSER, K. (1933): Echinocts. (Astroph.) capricornis niveus var. n., Kakteenkunde Jg. 1933 (1): 31-32

RIHA, J.; BUSEK, J. (1986): Astrophytum capricorne var. niveum a var. crassispinum, Kaktusy 22 (5): 99-103

VIERECK, H. W. (1939): Astrophyten, wie sie der Sammler in den Heimatgebieten sieht, Beiträge z. Sukkulentenkunde Jg. 1939 (1): 4-8

Figure texts in the article

Form 1:
The Astrophytum capricorne v . niveum on the margin of the plant group is shadowed during the greatest noon heat by a Gobernadora bush, which one is almost leafless in the wintertime, though.

Form 2:
Within the Niveum group a large plant dominates with a thick spine crests along the ribs, awarding a primeval appearance to it. Each rib has 40-50 areols. To this an age of about 50-100 years can be assessed to this Astrophytum.

Form 3:
One sees a spined, flourishing capable areole which isn't on the rib edge but surprisingly at a rib flank.

Form 4:
Two Astrophytum capricorne v. niveum from the western part of the Bolson de Cuatro Cienegas in the comparison. The plants there tend to flake reduction (left), however, flaked ones grow at the same location (right).

Footnotes and remarks:
(1) The stony, gravelly levels are called "bajadas" in her native country. Here are often erosion gutters, the "arroyos", which possess water only after intense rain fall.

(2) Pico Pajarito, 2772 meters over sea level in the western Sierra Anteojo.

(3) Cuatro Cienegas means "four marshes". Water places still are in the surroundings of the small town today, filled year-round and surprise the visitor with a wealth of marsh plants in the middle of the dry zone of the Bolson (Nyphea (waterlily), Utricularia).

(4) The name "niveus" (snow like) was taken by K. KAYSER because of the particularly thick white flakes of this Astrophytums.

(5) Larrea bushes often of Larrea tridentata (DE CANDOLLE) COVILLE, frequently dominate in the view of the Chihuahua arid regions. Mexicans call them therefore "gobernadora", ruler. However, one describes them also as a Kreosote shrub, since the leaves covered of a varnish layer on hot days smell intensive to Kreosot.

(6) All spiny shrubs are called in Mexico "mesquite", many of them Prosopis juliflora DE CANDOLLE.

(7) For ants the spermatic cords of seeds are a delicacy in the ripe Astrophytum fruits. They partly eat the seed appendages completely at the transport to their anthill and then having cleaned the seeds leave them. Under favourable environmental conditions a new Astrophytum generation then grows up along the former ant street. One mentions this distribution mechanism of the seeds Myrmecochorie.

(8 ) Presumale Yucca rigida (ENGELMANN) TRELEASE.

(9 ) In Mexico called "ocotillo".

(10) Presumable Dasylirion leiophyllum.

(11) Another poulation is mentioned in the Sierra Ovejas.

Photos:

plant cummunity, drawing
Astrophytum capricorne v. niveum (1)
Astrophytum capricorne v. niveum (2)
areole between ribs at Astrophytum capricorne v. niveum
Yucca rigida (ENGELMANN) TRELEASE ?
landscape at the basin of Cuatro Cienegas

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