HOOCK, H. 1996 . Kakt. and. Sukk. Band: 47 Heft (9) Seite 203-207 Am Standort von Astrophytum asterias (Zuccarini) Lemaire in Texas, U.S.A.
At the habitat of Astrophytum asterias (Zucc) . Lem. in Texas U.S.A.
On a sultry hot May day 1994 I drive from McAllen along the Rio Grande at the 'Texas Tropical Trail' in the direction of Rio Grande City to the location of Astrophytum asterias. The parts of still uncultivated landscape are marked by a tree vegetation consisting of oaks (Chaparral), acacias (Blackbrush) and prosopis (Mesquite), frequently towered above by palms. When the Spaniards discovered this valley therefore they called the powerful river which flows into the gulf 'Rio de las Palmas ' (palm river). Today's Mexican name 'Rio bravo', that is 'wild river', only applies actually to his upper reaches to the north of Santa Fe. But here, short before the muzzle it is a broad, deep green water that sluggish covers his last way to the golf between trees, pastureland and fields.
The surprising fact, that Astrophytum lives in Texas, is reported in 1933 by Clover . A cactus shipment in the year 1932 to the university of Michigan Botanical Gardens included a copy of this species and got collected in the Rio grandee Valley by Miss Flossie Garrison. The locations were pillaged fast in the following period. Already 1935 the Texas cactus dealer Pirtle complains about it, one must try around one two days to find only one plant. Today, unfortunately, all historical occurrences of the 'Star Cactus', as Astrophytum asterias is described here, disappeared in the administration districts Cameron and Hidalgo and in the adjacent northern Mexican Tamaulipas as well as in Nuevo Leon. Present a last habitat is known for a few persons in Starr County. There is no legal plant material in Europe since these cactuses stand under the most severe conservation. This is also a reason that in the literature on the Texas Astrophytum many wrong assumptions were expressed. My observations in Texas could not find significant differences in plant morphology compared with her Mexican relatives which occur south of Ciudad Victoria in Mexico.
The texan Asterias population consists of roughly 2000 copies and I can watch at my location visit more closely about 200 of them. They all have usually 8 ribs, embedded in the ground flatly, most inked reddish brown by the singing sun, but always well in condition. Fine flakes are distributed over the plant body arched or scattered. They don't offer them sufficient protection against the sun. The grass and the dry bush partly take over this function. Despite intensive search I don't find any copy with sharp rib edges as this is claimed again and again in the literature for this Asterias. Open flowers cannot be seen, but the Texas conservation authority botanists accompanying me describe them as known: yellow with orange till red tube
, diameter to 5 cm. Ripe fruits are already to see. The small reddish brown till black seeds lie scattered up to 20 cm around the plants. Ants tamper with a fresh fruit. The seed appendages are a popular food for her and one can assume that this represents an essential seed distribution mechanism of the species. All plant sizes of 2 to 10 cm of diameters can be found in which copies predominate with 4-6 cm. I often find groups from 5-10 pieces on few square metres, then there are gaps of 10-20 m again between the individuals. Four particularly beautiful and large 'Star Cactus' are bitten quite freshly in the middle. Presumably the local hare (Jackrabbit) thinks little of the rumour, Astrophytum asterias protects itself from muck by an adverse taste (Weniger, D. 1972). He consumes the valuable Astrophytums as vegetables. Similar damaged plants which already regenerate from the central axis by kid formation again, are found at other place. All new shoots have 8-ribs and are deep green.
The Jackrabbit represents presumably the least of the natural dangers for the existence of the cactuses. The change of the conditions of life under the influence of the surrounding land developed and cultivated by man is primarily problematic for the plant community . One has imported the not native buffalo grass (Cenchrus ciliaris) in the Texas pastural agriculture, that unchecked spreads at the location of the 'Star Cactus'. It is looking lovely into flower now around this season. But it is a serious threat with his growth height by 20-30 cm since it overgrows the flat Asterias and shadows them too much. The cows of the country owner have a free access here. Although they crush surely many cactuses they nevertheless keep the unstable life balance for the Astrophytum asterias upright by eating away the buffalo grass. The surrounding, shady dry bush (Bosque espinoso) was also changed in his earlier natural composition by settlement of trees growing more large. How far the change of ecology will lead for another reduction of the plant formation one cannot assess definitely yet because there are intensive population observations only for few years.
The heat reflects to the stones as big as a fist which lie around scattered, cover partly also thick the ground at sultry temperatures around 35 degrees. They are brown till rust-coloured and are so hot that one burns his fingers on it. However, the heat also has an advantage. The rattlesnake (Diamond Black) living here and her relatives prefer the afternoon nap at these unpleasant environmental conditions in cool foxholes. The gently corrugated area with mainly sandy loamy composition and few humus quotas reaches hardly differences in altitude of 10 metre. It is astonishing that a large portion of the Astrophytums is established on the upper areas and not in the valleys.
The succulent accompanied plants of Astrophytum asterias are: Coryphantha macromeris v. ruyonii, Echinocereus poselgeri (Wilcoxia poselgeri), Echinocereus reichenbachii v. fitchii (Hedgehog Cactus), Mammillaria heyderi (Nipple cactus), Opuntia leptocaulis (Tasajillo), Opuntia lindheimeri (Lindheimer prickly-pear), Sclerocactus texensis (Echinocactus texensis), Thelocactus bicolor (Glory of Texas) and Thelocactus setispinus.
The dry bush and the other plant community are marked by: Acacia rigidula (Blackbrush), Aristida sp., Bouteloua trifida, Bumelia celastrina (Coma), Castela texana (Amargosa), Cenchrus ciliaris, Ephedra antisyphilitica (popote), Isocoma drummondii (Goldenweed), Karwinskia humboldtiana (Coyotillo), Koberlinia spinosa (Allthorn), Monanthochloe littoralis (Shoregrass), Prosopis glandulosa (Mesquite), Varilla texana (Saladillo) and Ziziphus obtusifolia (Lotebush).
For the rescue of the last occurrence of Astrophytum asterias in Texas the American conservation authorities have planned extensive rescue measures. A temporary study covers the time period until the year 2009 and requires an estimated financial expense of several hundred thousand U.S. dollars. It has to be hoped that these projects are converted so that this gem under the Astrophytums remains unchanged for us. I assess the prospects for it better than for the Mexican habitat south of Ciudad Victoria, since the area has no free access for cactus collectors. The country owner confirmed in a conversation that illegally penetrating, suspicious persons must reckon with firearm use. This for general safety reasons and to the protection of the private property and not because of the 'Star Cactus'. Even the state supervisory authority had to catch the permission of the farmer for our visit at the habitat.
Map text:
On the map the historically known locations in Mexico and the USA are marked . All plant communities have presumably been lost by over-collection and country cultivation. Two populations still existing today aren't represented for reasons of the protection of plants. The one south of Ciudad Victoria and the other in Starr County Texas.
Figure texts:
Picture 1:
The location of the Texas Astrophytum asterias. It is characterized by gentle slopes and levels with grass and awl bush vegetation. The 'Star Cactus' grows preferentially in the light shade of other accompanying plants or also of rock. Predominantly the loamy clayey ground consists of navies sediments and is covered by gravel.
Picture 2:
Astrophytum asterias normally grows ground at once and adapted to the surroundings mimetically excellently. One cannot find it simple. The figure shows a typical plant of about 8 centimetres diameter with fruit remains and seeds.
Picture 3:
It seldom occurs that Astrophytum asterias forms a silhouette like this copy in the natural habitat. It is exposed to the burning sun without shade protection and nevertheless in excellent constitution.
Picture 4:
A plant group shows that the Texan Astrophytum asterias doesn't have any rib edges, what is suspected again and again .
Literature:
BENSON, L. (1982): The Cacti of the United States and Canada, Stanford University Press, Stanford, California
CLOVER, E. U. (1933): Astrophytum asterias in the United States, Desert Plant Life 5 (2): 20-21
CROSSWHITE, F. S. (1980): Dry Country Plants of the South Texas Plains, Desert Plants 2 (3): 143, 144
DAMUDE, N.; POOLE, J. (1990): Status report on Echinocactus asterias (Astrophytum asterias), U.S. Fish and Wildlife Service, Albuquerque, New Mexico: 1-58
Department of the Interior, Fish and Wildlife Service USA (1993): Endangered and Threatened Wildlife and Plants: Determination of Endangered Status for the Plant Astrophytum asterias (Star Cactus), Federal Register, Rules and Regulations 58 199: 53804-53807
FRICK, G. A. (1935): Fricks Notes, Cact. Succ. Journ. (US) 6 (12): 178
MITICH, L. W. (1988): The Mystery of Astrophytum asterias in the United States, Excelsa Jg. 1988 (13): 89-92
RUNYON, R. (1936): Cacti of the Lower Rio Grande Valley, Desert Plant Life 8 (2): 16-17
WENIGER, D. (1972): Cacti of the Southwest - Texas, New Mexico, Oklahoma, Arkansas and Lousiana: 70-71
Photos:
Astrophytum asterias, Starr County, Standort, habitat
Astrophytum asterias, Starr County, Pflanze (1), plant
Astrophytum asterias, Starr County, Pflanze (2), plant
Astrophytum asterias, Starr County, Pflanze (3), plant
Astrophytum asterias, Starr County, map
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