Mammillaria donatii (Schumann)

First description: Schumann Gesambeschr. Kakteen Nachträge: 135.1903

Body: Single, globular, sunken apically and covered with wool and spines, to 40-100 mm high and 40-90 mm in diameter.
Roots:Fibrous.
Sap: Without latex.
Tubercule: Conical, medium set, firm, 6-10 mm long and 5-8 mm thick. Bluish green.
Axil: With white wool.
Radial spine: 14 - 24, 2 - 7 mm long,the upper one shortest and thinnest, needle like, the sidemost longest and thickest, straight, horizontal radiating, glassy white to glassy yellow.
Central spine: 2, 5 - 12 mm long, thicker than radials, straight with thicker base, glassy yellow to brown with darker tip.
Flower: Bell - funnel form, 15 - 20 mm in diameter and long, silk carmine. Fruit: Club-shaped, 10-20 mm long, 3 - 5 mm wide. Ripens 8-12 monthts after flowering.
Seed: Brown, drop- to kidney shaped, 1 mm long and 0,8 mm wide. Hilum subbasal. Selffertile.
Flowering period in Cultivation in Europe: March - April.
Habitat Substrate: On hill slopes between limestone rocks in humus. 4-5 hours of sunshine a day.
Geographic Distribution:Mexico, Puebla, Azumbilla near Esperanza and Veracruz near Aculcingo and Tecomayuca.
Bibliography: Reppenhagen, Die Gattung Mammillaria.

M. donatti Rog 129.
A young 3 year old plant. There have been 2 collections of Rog 129. The 1st in 1990 has aff collina and again in 1994 has aff haageana collina, both from Azumbilla in Puebla. Hunt places M.donatti under M.haageana subsp haagena (Mamm. postscipts 7:12. 1998)

Is Reppenhagen right with M. donatii ? (PART 1)
There is an almost unmanagable number of names for plants from the genus Mammillaria as is generally known. Some names are relatively well known, others are less known. One can connect certain names to a completely specific type of plant and in other cases, one cannot assign names at all. From time to time new species are still being described, thus creating new names. At other times people try to reestablish longforgotten names or names rejected into synonymy a long time ago. This practice was used by W. Reppenhagen in “Die Gattung Mammillaria nach dem heutigen Stand meines Wissens, 1987”.
In this book, under number 191, Reppenhagen lists M. donatii BERGE, behind M. martinezii BACKEBERG and before M. albidula BACKEBERG in his systematic classification, as a good species for the first time, or better said, once again after a long period. In this article I would like to make an attempt to clearly show that this experiment of W. Reppenhagen can be considered entirely unsuccessful. Whether you share my opinion or not is left to your own decision. I would be pleased to receive responses and/or opinions, however. And perhaps, someone is in the possession of some kind of information or material through which one can see the whole from a different perspective. This might possibly lead to different conclusions.
M. donatii was described in 1903 by Berge in K. Schumann “Gesamtbeschreibung der Kakteen, Nachträge, p. 135”. Some short irrelevant data were published in the following years after which it became very quiet around M. donatii.
In 1968 D. Hunt, in the Journal of the Mammillaria Society (“Review of Mammillaria names in current usage”), wrote that M. collina, M. donatii and M. dyckiana could be distinct from M. elegans because of the smaller number of radial spines (15-18), at least if this feature would prove to be reliable. However, he also mentions that Señor Buchenau apparently does not share this opinion. In Bradleya 2/1984 (“A new review of Mammillaria names”) D. Hunt then writes: “In view of the unsatisfactory typification of the original M. donatii, the name is best discarded”.
In 1985 W. Reppenhagen published his field list as a “Sonderheft” (special issue) of the AfM and this list does not yet contain any entry for M. donatii. Two years later, in 1987, Reppenhagen places M. collina as a synonym of M. haageana in his systematic overview of the genus Mammillaria.
In his field list Reppenhagen has assigned three field numbers to M. collina:
Rep. 878 Mex., Veracruz, Tecamayuca, 1400 m, 22.10.1974,
Rep. 880 Mex., Veracruz, Acultzingo, 1800 m, 23.10.1974 and
Rep. 882 Mex., Azumbilla, Puebla, 2100 m, 23.10.1974.
Because Reppenhagen listed M. collina as a synonym of M. haageana, these three field numbers would have had to be ascribed to M. haageana. Yet, Reppenhagen did not do this, but he now assigned these three field numbers to M. donatii in his book “Die Gattung Mammillaria nach dem heutigen Stand meines Wissens, 1987”.
Part2
D. Hunt while writing about the distribution of species in general terms, once remarked that it is relatively unusual that more than one “good species“ of a clearly distinguished series will occur at one and the same location. In other words, it will be very doubtful that two closely related species share the same location. Apparently, W. Reppenhagen does not share this view for at the Azumbilla, Pue. site he claims to have found both M. haageana (Rep. 883) and M. donatii (Rep. 882).
A small annotation regarding the locality names: Reppenhagen employs the locality name Tecamayuca in his field list, but in his monograph the locality name is Tecomayuca. The actual name is probably Tecamalucan, a village which is situated around 10 km northeast of Acultzingo. Acultzingo is also seen being spelled as Aculcingo.
Acultzingo and Tecamalucan are located to the southeast of Esperanza, Azumbilla is located to the south of Esperanza.
The information about the Azumbilla, Pue. location is not very precise. Reppenhagen, in his description of the site, mentions that M. donatii (Rep. 882) is quite rare and can be found on the southeast slopes. Concerning M. haageana (Rep. 883), Reppenhagen writes that it occurs only sporadically on the barren limestone mountains and it is often to be found at the western slopes. Whether Reppenhagen is talking about two different sites or about just one site is not clear because the actual locations are unknown to me. However, Linzen et. al. in their contribution in Mtbl. 15(6) of 1991 on page 236 make the following note: “We were unable to confirm the observations that Reppenhagen made during his field studies at the site at Azumbilla. Therefore we have very considerable doubts about the correctness of his assignment”.
In the further process I will inform you about the precise locality and about the plant descriptions of the plants identified as M. donatii by Reppenhagen. In doing so, I will try to prove that the doubts of Linzen et. al. are justifiable.

On page 502 of his monograph Reppenhagen gives some additional information about the type locality of M. donatii: “Craig says: “...at Boca del Monte, near Esperanza”, where I also found it”. However, R.T. Craig had actually written in “The Mammillaria Handbook” (1945) on page 251: “Type locality: None given but reported from near Boca del Monte near Esperanza”. So, there appears to be a discrepancy between these two references.
In the original description of M. donatii Berge in K. SCHUMANN, “Gesamtbeschreibung der Kakteen, Nachträge”, p.135, 1903 no type locality or any other indication is given about where this plant can be found. All what is mentioned is: “Mexiko. Imported by Berge in Leipzig without specific locality”. Reppenhagen should have quoted this correct literature reference. This proves, so to speak, that Reppenhagen did not investigate these matters well enough.

Was Reppenhagen right with M. donatii? ( PART 2)

But now, from where did Craig have the information “reported from near Boca del Monte near Esperanza”? Quite probably this information comes from J.A. Purpus, for in 1909 he reports in a lecture (MfK 19 (1909) p. 71): “Als erste Vertreterin der Kakteenvegetation dieses Hochlandes wurde die niedliche M. donatii beobachtet; sie wächst an Felsen bei Boca del Monte, der Station von Esperanza, unter relativ feuchten Lebensbedingungen, weil die aus dem Tal von Orizaba aufsteigenden Nebel sich hier verdichten und reichlich Niederschlag erzeugen.“ “As the first representative of the cactus vegetation of this highland the lovely M. donatii was observed; it grows on rocks at Boca del Monte, the station of Esperanza, under relatively moist living conditions, because the fog which ascends from the valley of Orizaba condenses here and results in ample amounts of precipitation.“
J.A. Purpus therefore knew at least about the name and the description of M. donatii. He identified the plants which were discovered at Boca del Monte near Esperanza as this species. Three years after his lecture, i.e. in 1912, J.A. Purpus described M. collina based on plants which his brother C.A. Purpus had discovered south of Esperanza in the summer of 1907. He was able to observe and collect these plants himself at that location in the following year, i.e. in 1908. This can be concluded from the quite informative additional notes in his first description of M. collina. The 1909 lecture of J.A. Purpus referred to the trip which he had undertaken the year before. Therefore, two lines of thought are possible now:
1. During his trip of 1908 J.A. Purpus detected M. donatii and a further plant which he later described as M. collina; or
2. J.A. Purpus misidentified the plants, which his brother C.A. Purpus had discovered in 1907, as M. donatii. This latter option is more probable, because J. A. Purpus had not mentioned any further finds of Mammillarias in his 1909 lecture. The deviation from his original identification later on could have been caused by the colour of the flowers. In the first description of M. donatii by Berge and/or K. Schumann the colour of the flowers was mentioned as fiery carmine-red. Perhaps later during cultivation, J.A. Purpus observed that the flowers of the plants found by his brother were bright rose-red. Both lines of thought are, however, more or less only presumptions which can hardly be proved anymore in any way. This adds further support to the assumption that M. donatii is a doubtful species.
Now let me turn back to Reppenhagens further information about the type locality, “where I also found it”. In addition he writes: “Ich fand die Art an drei Plätzen südlich und südöstlich von Esperanza bei Azumbilla in Puebla und in Veracruz bei Acultzingo und Tecamayuca in Meereshöhen zwischen 1400 und 2100 m.“ Therefore: “I found the species at three places to the south and southeast of Esperanza at Azumbilla in Puebla and in Veracruz at Acultzingo and Tecomayuca at elevations of 1400 and 2100 meters.
This further information about the individual locations is confusing, or better unprecise, because it can be interpreted in different ways. Are we supposed to understand this sentence in such a way that Reppenhagen has found M. donatii south of Esperanza at Azumbilla in Puebla (Rep. 882) as well as southeast of Esperanza at Tecamayuca (Rep. 878) and Acultzingo (Rep. 880) in Veracruz? Or did Reppenhagen in fact mean that he has found M. donatii south and southeast of Esperanza and at Azumbilla in Puebla and Tecamayuca and Acultzingo in Veracruz? There are several reasons which seem to make the last mentioned interpretation less likely.
Reppenhagen did not assign any field number to a plant identified by him as M. donatii and found by him at Esperanza even though this could be the putative type locality.
However, Reppenhagen did find M. haageana at Esperanza (Rep. 924) and he describes the locality as follows: M. haageana grows with M. uncinata and M.
discolor var. ochoterenae at the rounded peak of the Esperanza mountain in short grass and fully exposed to the sun.
Further information about the site situation, the accompanying flora and the climate can be found at the Reppenhagen description of Rep. 922 (M. mystax). Here the text reads: Rep. 922 M. mystax, Esperanza PUE, 2500 m, 1.2.1975. A free-standing rounded mountain with meadow-like vegetation. An icy wind blows from the nearby Pico de Orizaba which carries a continuously frozen snow cap. The plant community on this side of the mountain consists only of grasses and herbs. On the top some dwarf cacti appear. On the lee side small shrubs, Nolina, Dasylirion, Agaves, Hechtias, Opuntias and Ferocactus are present. The calcareous rock of the subsoil is nowhere bare. Nevertheless the soil is rocky. The following Cactaceae are present: Echinofossulocactus crispatus, M. mystax, M. uncinata, M. discolor var. ochoterenae, M. haageana, Ferocactus hamatacanthus, F. recurvus, Opuntia huajuapensis and O. macdougaliana.
Echinofossulocactus crispatus has a mass occurrence in the western area of the peak. Cristates occur in outsized numbers. A little lower and in the wind shielded areas one can sporadically find Ferocactus hamatacanthus between low bushes. Ferocactus recurvus, which forms large groups, does also grow at higher elevations. In places where it is exposed to the wind, it remains smaller. Its spines often carry a black fungus-like coating.
M. mystax occurs widely scattered in wind protected areas of the small bushes. It grows there at open places between stones where it may get 3 hours of sun. The substrate contains much humus. It does not form offsets and it becomes unusually large. On February 1, 1975 it stood in flower, these flowers are particularly large and dark-carmine. On the same day at 15.00 pm it was 13 °C near a M. haageana. It was clear and windy.
Among the many species occurring at this site no M. donatii or other representative of the series Elegantes/Supertextae (with the exception of M. haageana) is being mentioned. If M. haageana and M. donatii would both have occurred at Esperanza, then we would have the situation that two valid species of one series would occur at the same site and this would clearly contradict the theory of D. Hunt.
As a last point it has to be mentioned that Linzen, Rogozinski and F. Wolf have also examined the surroundings of Esperanza quite thoroughly during their field investigations. They could not find an occurrence of M. donatii in this region and reported about only one species from the series Elegantes/Supertextae which had its distribution here (in Mtbl. AfM No. 5+6/1991). This species is M. collina J.A. PURPUS or M. haageana var. collina (J.A. PURPUS) LINZEN et. al.
part4
The reasons mentioned above make it very unlikely that Reppenhagen will actually have meant with his annotations that he had found M. donatii at Esperanza, the location described by Berge.
Reppenhagens confusing play with M. donatii as the main actor goes on, however, and becomes much more interesting. For this purpose we will look more closely at the site and plant descriptions of the three field numbers stated by Reppenhagen for M. donatii and we will compare this information with the description of M. donatii BERGE ex K. SCHUMANN. In the three descriptions of the plants from Azumbilla, Tecamayuca and Acultzingo there are written but unpublished recordings of W. Reppenhagen for his field number (translation and underlining by the author of this article):
Rep. 878
M. donatii México, Veracruz, Tecamayuca, 1400 m, 22.10.1974
An east-west running mountain range with high limestone hills. On the grassy stony slopes under the rocks some cacti can be found: Coryphantha greenwoodii, flat Opuntias and Stenocereus pruinosus. The slope is so densely populated with epiphytic Bromeliads that the Cerei almost disappear under them. The slope resembles a shaggy broom. The moist air which is brought up by the wind from the humid and hot lowland of Veracruz allows this lush epiphytic growth. In the rocks Tillandsia gigantea settles in large quantities. The funnel-shaped rosettes are more than 1 m high and are directly attached to the rocks by strong clip roots. The giant plants feed exclusively on the precipitation collected by the funnel-shaped leaves. M. donatii is rare: it grows in the limestone gravel of small rock crevices in a humus-rich soil. It receives sun for about 3-4 hours daily at this site. It is in flower at this moment and it carries ripe fruits in small numbers.
Body: globose, solitary, flowering heads 40-70 mm high, 70-90 mm thick. Tubercles: rather closely set, firm in texture, conical, 5-7 mm long, 5-6 mm thick, without milky sap, bluish-green. Radial spines: 13-15, 4-7 mm long, acicular, the upper ones the shortest and thinnest, straight, radiating and porrect, at times covering the body, glassy white to glassy yellow. Central spines: 2, 5-11 mm long, thick acicular, straight with thickened foot, glassy yellow to brown, with dark tip. Flowers: appear in April, several ones near the apex, only a few open simultaneously, slightly convex funnel-shaped, 18-22 mm long, 14-18 mm broad, carmine. Sepals: cuneate with blunt top, margins entire, carmine-pink with bright margins. Petals: lanceolate, 6-7 mm long, about 2 mm wide, margins entire (carmine, brighter near the throat. Fruits: mature about 12 months after flowering, in habitat and in cultivation in the fall, conical with large perianth residue attached, red, 3-5 mm thick, 10-20 mm long. Seed: dark brown, drop- to kidney-shaped, about 1.1 mm long, 0.9 mm thick, testa slightly wrinkled, hilum subbasal. It is not self-fertile.

Rep. 880
M. donatii México, Veracruz, Aculcingo, 1800 m, 23.10.1974
A southern incline of a very steep rocky limestone mountain. There are grassy places in the lower less steep places. Here grows Coryphantha greenwoodii. Higher up where it becomes stony and rockier, a very open xerophytic flora is encountered. Bromeliads are missing. It is difficult walking on the crumbly rocks. Besides low bushes one can find Agave lechuguilla, Dasylirion acrotrichum and Hechtia podantha. M. donatii is encountered in large numbers. Smaller and larger groups are found in exposed places of rock crevices. They get approximately five hours of sunshine. They are in flower and the flowers are quite large.
Body: globose, becoming a little elongated, solitary, 60-100 mm high, 60-80 mm thick. Tubercles: rather closely set, conical, about 7-8 mm long, 5-7 mm thick, without milky sap, bluish-green. Radial spines: 20-24, 3-6 mm long, acicular, the upper ones the thinnest and shortest, all radiating and porrect, glassy white. Central spines: 1-2, 5-12 mm long, acicular, straight, when there are two centrals then the lower one is the longest, glassy white to glassy yellow or brown with dark tip. Flowers: appear in April/May in rings around the apex, only a few open simultaneously, convex bell-shaped, 16-19 mm long, 18-22 mm wide, silk-carmine. Sepals: few, carmine, tapered, margins entire, with white margins. Petals: lanceolate, 8-9 mm long, 2-3 mm wide, margins entire, carmine or pink with carmine midstripe. Fruits: mature about 12 months after flowering, conical with perianth residue attached, 4-5 mm thick and 15-25 mm long, carmine. Seed: brown, kidney-shaped, 1 mm long and 0.8 mm thick, wrinkled testa, hilum subbasal. It is not self-fertile.
Rep. 882
M. donatii México, Puebla, Azumbilla, 2100 m, 23.10.1974
Relatively bald limestone mountains on the western side of the Puerto del Aire pass that forms the border between Veracruz and Puebla. The mountains are not very steep, but very rocky. Windswept shrubs and cushion forming plants indicate that there are frequently very strong winds here. The wind blows across the pass, up from the plains of Veracruz. Nevertheless the air is quite cold when it arrives here as I found out. The Valle de Tehuacán begins here. This valley has a dry and hot climate with cold nights. In the plant community cacti and other succulents take a favoured place. Occasionally they dominate the flora. Examples of this are the large Cereus fields of Zapotitlan and Ajalpan. The plant community around Azumbilla is certainly not as cactus-rich as it presents itself further south, but a lot of species which are typical for this region do occur here already. Among other plants: Agave atrovirens, A. lecheguilla, Coryphantha greenwoodii, C. retusa, Echinocactus platyacanthus, Ferocactus robustus, Hechtia spec., Mammillaria donatii, M. haageana, M. sphacelata, Yucca periculosa and several Sedum- and Echeverias-species.
M. donatii is quite rare. It can be found on southeastern slopes, where it grows between blocks of stone which offer sufficient wind protection. The substrate is a weakly humous mineral earth. It gets sun about 3 hours of sunshine at this site.
Body: globose to somewhat elongated, flowering heads 40-90 mm high, 40-70 mm thick. Tubercles: quite densely set, conical, 8-10 mm long, 6-8 mm thick, without milky sap, dark gray-green. Radial spines: 15-18, 2-7 mm long, fine acicular, the upper ones the shortest and thinnest, the ones on the side the longest and thickest, straight, smooth, radiating, sometimes covering the body, glassy yellow. Central spines: 2, 4-9 mm long, thicker than the radial spines, the upper one the longest and thickest, bent towards the apex, brown but lighter below. Flowers: appear in March/April in a ring around the apex, only a few open simultaneously, funnelform, 14-16 mm long and 15-20 mm wide, silk-carmine. Sepals: cuneiform, margins entire, brownish-red with bright margins. Petals: linear-lanceolate, 8-9 mm long and 1.5 to 2 mm wide, margins entire, silk-carmine with lighter tinted edges. Fruits: mature 6-7 months after the flower, clavate with large perianth residue attached, red, 3-5 mm thick and 10-20 mm long. Seed: brown, drop-shaped, about 1 mm long and 0.8 mm wide, testa somewhat pitted, hilum small, subbasal.

Was Reppenhagenhagen right with M. donatii? ( PART 3)

67a. M. donatii BERGE ex K. SCHUMANN
Mexico. Without specific locality introduced by Berge in Leipzig
Annotation: This very elegant, small species is closely allied to M. elegans DE CANDOLLE. It distinguishes itself by the decisively blue-green colouring of the body.
Body: simple, later sparsely offsetting, globose to flattened globose, rounded above, slightly sunken apex, closed with white wool and surmounted by black-brown spines, up to 8 cm in diameter. Tubercles: arranged in 13 and 21 spirals, conical, to 8 mm high, shorter near the top, bright cyan-coloured. Areoles: 2 mm in diameter, circular, dressed with white wool, soon becoming naked. Axils: naked. Radial spines: 16-18, aciculate, radiating, the middle ones the largest, up to 8 mm long, glassy. Central spines: 2, the lower one the largest, 10 mm long, stronger, straight, pointed and directed downward, the other one directed upward, young spines are black-brown, later all spines become grey. Flowers: a few, close to the apex, the length of them is 15 mm, no wool at the basis, funnel shaped, 12-14 mm as the largest diameter. Petals: lanceolate, tapering off to a point, fiery carmine-red. Ovary: turbinate (inversely conical), greenish-white; stamens: less than half the length of the flower; filaments: white; anthers: yellow. Style: white, well surmounting the anthers with four spreading stigma lobes of the same colour.
Let us first consider the three descriptions of Reppenhagen and especially the information underlined by me. For the two finds from Veracruz Reppenhagen indicates the following information: Fruits mature about 12 months after flowering, testa of seeds weakly wrinkled or wrinkled. Furthermore he writes that the plants on the 22th October and 23th October 1974 are in flower. These data are different from the data of his find of M. donatii from Azumbilla. Here the fruits mature 6-7 months after flowering, testa are somewhat pitted and because Reppenhagen in the site information of his Rep. 882 does not mention that the plants are in flower, this can be interpreted only in such a way that he did not encounter flowering plants on the date of his visit. Certainly, one could also consider the options that Reppenhagen has jumbled up his seed probes or that the plants at Azumbilla normally do flower in the fall, except for this year. I also realize that there can be considerable differences in the time needed for the fruits to mature, but honestly I do not believe that in this case. Exactly these three features, flowering period in the fall, wrinkled seed testa and a quite long maturity time of 12 months, are all features which are very characteristic for species of the M. discolor Group, series Heterochlorae. In my opinion, Reppenhagen may have made a mistake in the case of M. donatii, but whether this mistake is with the seeds, the plants or his field notes, I do not know.

W. Reppenhagen has observed very accurately when a species flowers in nature and in cultivation, whether a species is self-fertile or self-sterile, and how long the fruits take to mature. Hardly any other field collector or grower can beat him in this respect. Unfortunately, too little attention is usually being paid to these important and also characteristic features. This is probably caused by the fact that it is very difficult or impossible to study these features at the field locations. From there, some specimens would have to be taken into cultivation, but this is not possible without running into problems and anyhow, this is not even allowed anymore.
Furthermore the plants would have to be observed over a longer period in cultivation and this is something which is hardly being done at present. In the days of Reppenhagen there were no problems with the removal of plants from field locations and this allowed Reppenhagen to observe a lot of his finds in cultivation over a long period of time.
Very probably, W. Reppenhagen did not determine the fruit maturity times in habitat, but quite likely, they will have been based on observations of cultivated plants. These maturity times were therefore established under almost identical conditions of cultivation for different taxa. Reppenhagen classified the phenological feature of the fruit maturity time as very characteristic and specific and considered it to be of great importance. And so he employed this feature as an important distinguishing factor for his newly described species. A tabular survey of 18 plants in "Die Gattung Mammillaria nach dem heutigem Stand meines Wissens, 1987" gives the fruit maturity times of these species (time for the fruit to mature is given in months):
M. puberula (6- M. brevicrinita (2)
M. pottsii v. pottsii (6) M. pottsii v. multicaulis (3)
M. apamensis (2) M. discolor (10)
M. isotensis (4-5) M. gasterantha (3)
M. compacticaulis (14-18) M. bambusiphila (4)
M. crassior (6- M. spinosissima (12-14)
M. silvatica (14) M. crassior (6-
M. claviformis (16-19) M. hubertmulleri (12)
M. krassuckae (4) M. rekoi (12-14)
M. monticola (12) M. conspicua (7-
M. lanigera v. juxtlahuacensis (6) M. lanigera v. lanigera (12)
M. albata (6- M. leucocentra (12)
M. parrasensis (12) M. grusonii (4-7)
M. crassa (3) M. pettersonii (6)
M. bocensis v. rubida (12) M. bocensis v. bocensis (6)
M. centralifera (8-10) M. compressa (3-4)
M. rioverdense (6) M. saxicola (10)
M. erythra (5) M. mystax (12)
Which species are actually involved in the case of the Reppenhagen finds from Veracruz is unclear, but what can be said, however, is the following: If one uses the descriptions of Reppenhagen as a basis, Rep. 878 and Rep. 880 can certainly not be one of the species discussed here, i.e. neither M. donatii nor M. collina or M. haageana.
The description of the Rep. 882 from Azumbilla at first sight corresponds quite well with the description of M. donatii. On closer examination one finds, however, several small differences, particularly in the body color, the flower size and the flower color which factors, when combined, must lead to the conclusion that Rep. 882 is not M. donatii BERGE ex K. SCHUMANN, but M. collina J.A. PURPUS and/or M. haageana PFEIFFER sensu REPPENHAGEN.
Let‘s summarize:
The description of M. donatii by Berge ex K. Schumann was quite detailed compared to other descriptions of those days. However, information about the type locality and a corresponding illustration are lacking. The authors place M. donatii into the series XI. Elegantes as number 67a, behind number 67 M. elegans. In cultivation M. donatii had disappeared very fast and from the illustration which was published in 1920 by Britton & Rose in The Cactaceae Vol. 4 on page 111 – the illustration is of a plant that they had obtained from Haage and Schmidt – it is not very clear anymore, whether the illustration is in agreement with M. donatii as described by Berge, at least there is no further proof or evidence for that. Therefore, an unambiguous assignment as to which plants correspond to M. donatii BERGE ex K. SCHUMANN is not possible anymore.
The attempt by Reppenhagen to establish M. donatii (which had already disappeared into synonymy) once more as a good species can be considered as completely unsuccessful, for the reasons given above. Furthermore, the illustration in Reppenhagens book on page 502 shows a plant which is currently known under the name M. collina. Neither his plants found at Azumbilla in Puebla, nor the plants found at Acultzingo and Tecamayuca in Veracruz correspond to the description of M. donatii.
The illustration in Britton & Rose already vaguely resembles a plant which has its distribution in Veracruz and which has been described by Linzen, Rogozinski and F. Wolf under the name M. acultzingensis in 1994. Because there is legitimate doubt that the illustrated plant in Brittton & Rose can be identified as M. donatii, M. acultzingensis cannot be viewed as a redescription of M. donatii. It makes little sense to consider M. donatii as a good species and it also does not make any sense to place M. donatii as a synonym of any other species in the M. haageana or the M. elegans-haageana group of forms, as for example J. Pilbeam does in his book “The Cactus File Handbook 6, Mammillaria”. Here he views M. donatii together with M. dyckiana ZUCCARINI (1837) and M. kunthii EHRENBERG (1844) as a synonym of M. haageana ssp. haageana. The name M. donatii should better be classified as dubious and also be treated as such, or as D. Hunt already wrote in 1984: In view of the unsatisfactory typification of the original M. donatii, the name is best discarded.
An open question remains, namely which species has actually been found by W. Reppenhagen at Acultzingo and Tecomayuca (Tecamalucan). Perhaps this question is an incentive for Mexico-visitors to undertake once again more precise field research in this region. M acultzingensis LINZEN et. al. which grows at Acultzingo, Veracruz cannot be connected to Reppenhagens plants because M acultzingensis clearly is a representative member of the series Elegantes/Supertextae with its dark red flower, the pitted seed-testa and a fruit maturity time of approx. 6 months (unless Reppenhagen has made some mistakes as suggested above). Perhaps some of you prefer to consider M. acultzingensis as a subspecies of M. haageana as D. Hunt has proposed in 1997. Or perhaps you will agree with the latest opinion of D. Hunt in The New Cactus-Lexicon and see M. acultzingensis only as a synonym of M. haageana. I do not support these two views, however, and perhaps I will report about this very characterstic species (in my opinion) in one of the next issues of this journal.
Acknowledgement:
I would like to thank O. Appenzeller for the critical check of the German text and T. Linzen and M. Lacoste for the appropriation of photographs. My very special thanks go to Wolter ten Hoeve for his help in the translation of the original German text of this manuscript and for his useful remarks concerning the views presented in this publication.

Holger Rudzinski