ALBERT

Description: The chromosome numbers of 16 species of Angiosperms, collected in Cameroun and the Ivory Coast, were determined. The numbers given for 14 species are new, in the remaining species the results of other authors could be confirmed.

Description: The chromosome number of 157 species of Angiospermae occurring in the Netherlands is dealt with.

Description: The chromosome numbers of 31 species of Angiospermae collected in S. Brazil were determined. Of these species 5 were studied before, the other numbers are new, 11 are first counts for genera and one even for a family. Some notes on the cytology and morphology are added.

Description: Previously, the chromosome numbers of some species of Loganiaceae were dealt with (Gadella, 1961, 1962, 1963). The chromosome numbers of 7 species are reported in this paper, of which 4 species, all belonging to the genus Strychnos, had not been investigated cytologically before. The materials, kindly supplied to me by Dr. A. J. M. Leeuwenberg and by Ir. F. Breteler, were collected in the form of seed-samples in the Ivory Coast and in Cameroun. The plants of 2 species originate from botanical gardens. Living material of all species (except for Strychnos lernata Gilg. ex Lwb.) is grown in the botanical garden of Wageningen (WAG). The determination of the chromosome numbers was based on the study of roottipmitoses. Roottips of the plants were fixed in Karpechenko, embedded in paraffin, sectioned at 15 micron and stained according to Heidenhain’s haematoxylin method. The results may be summarized as follows: 1. Nuxia floribunda Benth.: 2n = 38 Origin of the material: S. Africa, obtained from the University of Stellenbosch. Seeds probably collected in the wild. Herbarium material of the mother-plant: J. J. Bos, no. 310 (WAG). Herbarium material of seedling: A. J. M. Leeuwenberg no. 3665 (WAG). References: Gadella (1963): 2n = 38. 2. Strychnos dinklagei Gilg.: 2n = 44 Origin of the material: Ivory Coast, Forêt d’Abouabou, between Abidjan and Grand Bassam. Herbarium material of the mother-plant: R. A. A. Oldeman no. 845 (WAG). Herbarium material of the seedling: A. J. M. Leeuwenberg no. 3561 (WAG). References: Gadella (1963); 2n = 44. 3. Strychnos innocua Del. subsp. innocua: 2n = 44 Origin of the material: Ivory Coast, 16 km S. of Ferkéssédougou. Herbarium material of the mother-plant: A. J. M. Leeuwenberg no. 4435 (ABI, WAG). 4. Strychnos millepunctata Leeuwenberg: 2n= 441) Origin of the material: Ivory Coast, Forêt d’Abouabou, between Abidjan and Grand Bassam. Herbarium material of the mother-plant: J. J. F. E. de Wilde & A. J. M. Leeuwenberg no. 3447 (ABI, WAG). 5. Strychnos samba Duvign.: 2n = 44 Origin of the material: Cameroun, 4 km S. of Nguélémendouka. Herbarium material of the mother-plant: F. J. Breteler no. 2051 (WAG). 6. Strychnos spinosa Lam.: 2n = 44 Origin of the material: obtained from the botanical garden of Groningen, the Netherlands, origin unknown. Herbarium material of cutting: A. J. M. Leeuwenberg no. 3564 (WAG). References: Mangenot and Mangenot (1958): 2n = 44. Miège (1960): 2n = 44. Gadella (1962): 2n = 44. 7. Strychnos ternata Gilg. ex Leeuwenberg: 2n = 44 1) Origin of the material: Cameroun, 27 km from Bertoua on road to Bétaré Oya. Herbarium material of the mother-plant: F. J. Breteler no. 2196 (WAG). Herbarium material of the seedling: F. J. Breteler no. 2994 (WAG). Twenty-one species of the genus Strychnos have been studied up to the present. The following chromosome numbers have been counted: 2n = 24 (3 species, counted by Mohrbutter, 1936); 2n = 44 (16 species); 2n = 88 (2 species). From these data the conclusion may be drawn that the more common basic number of the genus Strychnos is X = 11 or 1 = 22.

Description: The chromosome numbers of 67 species of Dutch Angiosperms were determined. Notes on 11 species are added.

Description: In Sweden Erlandsson (1942) showed that the species Parnassia palustris L. has two chromosome numbers, 2n = 18 and 2n = 36. Rozanova (1940) found the same numbers in plants collected in the U.S.S.R. Some morphological differences could be demonstrated in the Swedish material (Erlandsson, 1942). This was confirmed by Löve and Löve (1944) and, therefore, these authors (1950) distinguish 2 species: the diploid Parnassia palustris L. em. Löve and the tetraploid Parnassia obtusiflora Rupr. em. Löve, also separated by sterility barriers and by their geographical distribution. In the Netherlands a tetraploid population was found by Gadella and Kliphuis (1963). As the tetraploid population occurs in an area situated far south of the circumpolar distribution area of the tetraploid plants, it seemed worthwhile to determine the chromosome numbers of other plants of Parnassia palustris L. growing in the Netherlands.

Description: The present paper, the fifth¹) in this series, is a continuation of the documented list of chromosome numbers of Angiospermae occurring in the Netherlands. In this paper 49 species and two hybrids are listed. Some species show variation in chromosome number, as was concluded after comparison of our results with those of other authors [cf. the lists published by Löve and Löve (1961); Cave et al. (1956-1964); Ornduff (1967, 1968, 1969); Solbrig and Gadella (1970); Moore (1970)]. Some notes on 14 species and two hybrids are given.

Description: 106 populations of Symphytum officinale were cytologically investigated. The distribution of white-flowered diploids and white- and purple-flowered tetraploids in Europa is discussed. The authors present a hypothesis which aims to give an explanation for the observed differences in distribution pattern.

Description: 1. The chromosome numbers of 38 species belonging to 11 genera of the tribe Campanuleae of Schönland’s system were determined. 13 of these species had not yet been investigated before. 2. A discussion is given of the differences between the present author’s results and those of other authors. 3. The systematic position of the species of Campanula with the diploid chromosome number 2n = 28 is reviewed. Some arguments are presented in favour of transferring Campanula erinus L. and Campanula drabifolia Sibth. to Dumortier’s genus Roucela. 4. A hypothetical explanation of the origin of the chromosome numbers 2n=28, 30, 32 and 34 of the genus Campanula is given. 5. The inclusion of Specularia perfoliata A. DC. and Specularia biflora Fisch. et Mey. in Triodanis is supported by cytological evidence. 6. Campanula vidalii Wats. and Campanula americana L. should be placed in the genera Azorina and Campanulastrum, respectively, both on morphological and cytological grounds. 7. The segregation of the genera Asyneuma, Synotoma, and Petromarula from Phyteuma is supported by cytological evidence. 8. The relation between the genera Campanula, Symphyandra, and Adenophora is discussed.

Description: In the present paper, the third in this series, the chromosome numbers of 46 species of Angiospermae occurring in the Netherlands, are listed. A comparison of our results with data derived from literature revealed the fact that these species show cytological differentiation in their distribution area.