CHROMOSOME NUMBERS IN THE COMPOSITAE. X. NORTH AMERICAN SPECIES

Chromosome counts from 132 plant populations representing 124 taxa (in 67 genera) are reported. These include previously unreported counts for over 70 species and 5 new generic counts (Hofmeisteria, x = 19; Oxypappus, x = 10; Pterocaulon, x = 10; Stenocarpha, x = 8; and Urbinella, x = 8). Two new base numbers are reported for specieis of Perityle (P. californica, x = 13 and P. palmeri, x = 17), and previously unreported n numbers have been found for species of the genera Bidens (n = 17) and Hymenostephium (n = 21). Several gametic cells with differing meiotic configurations were found in the same head of Stevia viscida (n = 11 pairs; 11 pairs and 11 univalents; 33 univalents). When appropriate, the chromosomal information has been related to systematic problems, especially for genera of the subtribes Flaverinae, Coreopsidinae, Galinsoginae and Peritylinae.     

CHROMOSOME NUMBERS IN PERITYLE AND RELATED GENERA (PERITYLANAE-COMPOSITAE)

Chromosome numbers are presented for 28 species of the genus Perityle, one putative inter-sectional hybrid, two species of Amauria, one species of Eutetras, and one species of Pericome. For Perityle, initial counts are recorded for 12 species of sect. Laphamia (n = 16, 17, 18, 36, ca. 102) and 11 species of sect. Perityle (n = 11, 12, 13, 16, 17, 18, 19, 34, 51). Chromosome numbers for the two species of Amauria (n = 18) are first reports for the genus. Including the current information, chromosome numbers have been recorded for 37 of the approximately 50 species recognized for Perityle. At least 24 taxa have numbers of n = 17, suggesting a base chromosome number of x = 17 for Perityle.     

A CYTOTAXOXOMIC SURVEY OF MELAMPODIUM (COMPOSITAE-HELIANTHEAE)

Turner , B. L.. and R. M. King . (U. Texas, Austin.) A cytotaxonomic survey of Melampodium (Compositae-Heliantheae). Amer. Jour. Bot. 49(3): 233–26. Illus. 1962.—Chromosome counts are reported for individuals from 89 populations of Melampodium representing 26 species The genus is multibasic with x = 9, 10, 11, 12, 16 and 23. Chromosome numbers on a base of x = 10 characterize the section Melampodium while basic numbers of x = 23, 16, 12, 11 and 9 occur in the section Zarabellia. Melampodium camphoratum (n = 16) differs from all other species examined in having relatively small meiotic chromosomes. Only 6 of the 23 species are polyploid or have polyploid races. Melampodium leucanthum and M. cinereum have both diploid and tetraploid populations; the latter occur without any apparent morphological or geographical correlation and are probably autoploid in origin. A survey of the basic chromosome numbers known for other genera of the subtribe Melampodinae (12 of 22 genera) is presented. and it is suggested that x = 10 is the most probable basic number of the genus and subtribe.     

CHROMOSOME NUMBERS IN THE LEGUMINOSAE. III. SPECIES OF THE SOUTHWESTERN UNITED STATES AND MEXICO

Turner, B. L., and Olin S. Fearing. (U. Texas, Austin.) Chromosome numbers in the Leguminosae. III. Species of the Southwestern United States and Mexico. Amer. Jour. Bot. 47(7) : 603–608. Illus. 1960.—Chromosome counts for 43 species of the Leguminosae from the southwestern United States and Mexico have been reported. These include first reports for 42 taxa of which 16 are for the subfamily Mimosoideae. Olneya tesota (2n = 18) is the only new generic count listed. Chromosome reports of particular significance include a single polyploid count for a North American species of Acacia, as well as diploid and tetraploid counts for closely related taxa in this genus. Four species of the genus Schrankia were found to be diploid with In = 26, indicating a base of x = 13 instead of the x = 8 reported by some previous workers. Leucaena pulverulenta was found to have a diploid count of 2n = 56 indicating a base of x = 14.     

CHROMOSOME NUMBERS IN THE COMPOSITAE: COLOMBIAN SPECIES

Chromosome numbers are presented for 76 species belonging to 35 genera of Compositae from Colombia. Thirty-nine species and three genera, Espeletia (x = 19), Steiractinia (x = 14), and Vasquezia (x = 19), are reported for the first time. New base numbers or chromosome series are recorded in Baccharis (B. nitida, n = 25), Calea (C. caracasana, n = 24), and Liabum (L. mega-cephalum, n = 10).     

CHROMOSOME NUMBERS IN UMBELLIFERAE. III

Chromosome numbers are reported for 156 collections representing 100 taxa of Umbelliferae. Approximately two thirds of the collections are from Mexico, Central and South America and indicate a high percentage of polyploid species in certain genera found in this area. Chromosome numbers for plants belonging to 78 taxa are published here for the first time, previously published chromosome numbers are verified for 18 taxa and chromosome numbers differing from those previously published are reported in seven instances. No chromosome counts have been previously published for nine of the genera included here. Further aneuploidy and polyploidy were found in Eryngium, and Lomatium columbianum has been found to be a high polyploid with 2n = 14x. Every chromosome count is referable to a cited herbarium specimen.     

New chromosome counts and evidence of polyploidy in Haageocereus and related genera in tribe Trichocereeae and other tribes of Cactaceae

Chromosome numbers for a total of 54 individuals representing 13 genera and 40 species of Cactaceae, mostly in tribe Trichocereeae, are reported. Five additional taxa examined belong to subfamily Opuntioideae and other tribes of Cactoideae (Browningieae, Pachycereeae, Notocacteae, and Cereeae). Among Trichocereeae, counts for 35 taxa in eight genera are reported, with half of these (17 species) for the genus Haageocereus. These are the first chromosome numbers reported for 36 of the 40 taxa examined, as well as the first counts for the genus Haageocereus. Both diploid and polyploid counts were obtained. Twenty nine species were diploid with 2n=2x=22. Polyploid counts were obtained from the genera Espostoa, Cleistocactus, Haageocereus, and Weberbauerocereus; we detected one triploid (2n=3x=33), nine tetraploids (2n=4x=44), one hexaploid (2n=6x=66), and three octoploids (2n=8x=88). In two cases, different counts were recorded for different individuals of the same species (Espostoa lanata, with 2n=22, 44, and 66; and Weberbauerocereus rauhii, with 2n=44 and 88). These are the first reported polyploid counts for Haageocereus, Cleistocactus, and Espostoa. Our counts support the hypothesis that polyploidy and hybridization have played prominent roles in the evolution of Haageocereus, Weberbauerocereus, and other Trichocereeae.     

CHROMOSOME COUNTS OF COMPOSITAE FROM THE UNITED STATES AND MEXICO

Chromosome counts are reported for 126 taxa representing 122 species and 61 genera of Compositae. First reports include two genera, Stylocline (n = 14) and Chromolepis (n = 19), 17 species, two infraspecific taxa, and one interspecific hybrid. Five additional taxa have chromosome numbers differing from previously published accounts. Carminatia is reinstated to generic status.     

CHROMOSOME NUMBERS IN COMPOSITAE. II. HELENIEAE

Raven , Peter H. (Rancho Santa Ana Botanic Garden, Claremont, Calif.), and Donald W. Kyhos. Chromosome numbers in Compositae. II. Heleniae. Amer. Jour. Bot. 48(9): 842–850. Illus. 1961.—Chromosome counts are now available for 42 of the approximately 55 genera of Compositae, tribe Helenieae, which is predominantly a group of western North America. These chromosome numbers are summarized here at the generic level, and 100 original counts for the tribe are added, including what seem to be the first published reports for the genera Amblyopappus, Baeriopsis, Hulsea, Jaumea, Pericome, Rigiopappus, Trichoptilium, and Venegasia, as well as for many species. The phylogeny of Chaenactis is discussed in the light of published records and 46 original counts, and C. douglasii is shown to include plants in which n = 6, 12, and 18, which differ somewhat morphologically. Helenium has species which have a complete series of aneuploid numbers from n = 13 to n = 17. Chromosome numbers coincide with morphological variability in indicating that Helenieae are a diverse group. More detailed studies of various kinds will be necessary before the genera of Helenieae can be re-aligned effectively, but it is evident that different genera show affinities with various other tribes of the family. Nevertheless, it is thought to be convenient to continue to recognize Helenieae at the tribal level for the present.     

CHROMOSOME NUMBERS IN THE COMPOSITAE. XII. AUSTRALIAN SPECIES

Chromosome counts are reported for plants from 171 populations of Australian Compositae; most of these are first reports for the approximately 104 taxa distributed among 37 genera. New generic counts with base numbers indicated include: Astereae —Bellida (x = 9), Minuria (x = 9); Inuleae —Angianthus (x = 12, 13), Calocephalus (x = 7), Cephalipterum (x = 12, 14), Craspedia (x = 11), Gnaphalodes (x = 10), Gnephosis (x = 4, 12), Myriocephalus (x = 6), Isoetopsis (x = 17); Calenduleae —Tripteris (x = 8); and Artcoideae —Arctotheca (x = 9). Most of the counts were from the tribes Astereae (47) and Inuleae (95). The phyletic import of these data is discussed selectively and comparisons are made with the chromosomal variation found in the Australian desert Compositae with that found in the North American desert Compositae.     

Chromosome studies: Latin American Compositae

Chromosome observations reported here from 98 collections representing 91 species from 58 genera of Compositae provide taxonomically useful information. First counts for 52 species, including first counts for eight genera (Alepidocline [n = 8], Damnxanthodium [n = 12], Dyscritothamnus [n = 20 in both species], Idiopappus [n = ca. 31–33], Oblivia [n = 16], Oteiza [n = 17 + 0–3 f], Rensonia [n = 17], and Viguethia [n = 19]), may prove to be especially interesting in relation to generic alignments of the species and tribal or subtribal alignments of the genera.     

CHROMOSOME NUMBERS IN COMPOSITAE. VI. SENECIONEAE. II

Chromosome counts are reported for 76 taxa and 2 natural hybrids of tribe Senecioneae (Compositae). First counts are reported for several species of Senecioneae as well as for the genera Cadiscus and Whitneya. New chromosome numbers are added to those previously known in Arnica, Cacalia, and Senecio. Additional counts from Arnica support our previous suggestion that x = 19 for this genus. It is assumed that observed meiotic irregularities are associated with apomixis in this genus. Basic chromosome numbers for various New World sections of Senecio are proposed, and certain problems of sectional relationships in this genus are discussed. Chromosome numbers and plant morphology of Cadiscus, Hulsea, and Whitneya indicate that these genera should be removed from Helenieae to Senecioneae. The possible affinity of the anomalous genus Adenocaulon with Mutisieae is discussed. Data presented in the paper further support our earlier proposal that the basic chromosome number for Senecioneae is x = 10.     

Chromosome numbers in Tripleurospermum Sch. Bip. (Asteraceae) and closely related genera: relationships between ploidy level and stomatal length

This study includes 24 reports of chromosome counts in Tripleurospermum Sch. Bip. (20 taxa), Anthemis L. (1 species) and Matricaria L. (3 taxa) belonging to the tribe Anthemideae of the family Asteraceae from Turkey. Chromosome numbers of these taxa are 2n = 2x = 18, 3x = 27 and 4x = 36. Nine counts are new reports, one is not consistent with previous report, and the remainder confirm earlier information. Statistically significant differences depending on ploidy level, stomatal length or environmental factors such as altitude were determined in Tripleurospermum. Several systematic and evolutionary aspects of the genera are discussed in the light of chromosomal data.     

CHROMOSOME NUMBERS OF SOME EAST AFRICAN GRASSES

Chromosome numbers of 133 collections of grasses belonging to 51 genera and 105 species are reported here for material from East Africa. These include first counts for 5 genera and 51 species. The basic chromsome number of x = 6 has been found in Sporobolus; x = 10 in Loudetia and x = 13 in Pentaschistis have been confirmed. It is pointed out that chromosomes of Eragrostis vary considerably in size. The genera Harpachne, Commelinidium, Acritochaete, Pseudechinolaena and Exotheca, which are cytologically examined for the first time, have chromosomes with the socalled “panicoid” features, viz., chromosomes with small size and x = 9 or 10.     

Chromosome numbers of dominican compositae

Chromosome numbers of 34 species of Dominican Compositae in 26 genera and nine tribes are reported. First counts are given forCoreopsis buchii (2n = 64),Lagascea mollis (2n = 34),Spilanthes urens (n = 16),Liabum subacaule (n = 18),Eupatorium sciatraphes (2n = 40),Hieracium gronovii (2n = 18),Vernonia buxifolia (2n = 34),V. sprengeliana (2n = 34),V. racemosa (2n = 28), andChaptalia leiocarpa (2n = 48,ca. 58). Our report forNarvalina domingensis (2n = 120) is the first for any species of this genus.     

CHROMOSOME NUMBERS AND THEIR SYSTEMATIC IMPLICATIONS IN HAWAIIAN LOBELIOIDEAE (CAMPANULACEAE)

Chromosome numbers are reported for 20 collections of Hawaiian Lobelioideae (Campanulaceae), representing six genera, 13 species, and two interspecific hybrids. All are n = 14. Chromosome numbers are reported for the first time for eight species of Clermontia, Cyanea, Delissea, Lobelia, and Trematolobelia; the report for Delissea is the first for that genus. Additional determinations confirmed previously reported numbers in five other species of Brighamia, Clermontia, and Cyanea. Chromosome numbers are now known for all seven genera and 20 of the 110 species. All accepted counts are n = 14. It is suggested that all Hawaiian Lobelioideae share this number and are paleotetraploid. There is no evidence that the prolific speciation evident among these plants was accompanied by euploid or aneuploid change in chromosome number. The Hawaiian Lobelioideae, particularly the monophyletic lineage of 91 baccate species, offer further support for the generalization that change in chromosome number is an uncommon mode of speciation in insular floras.     

CHROMOSOME NUMBERS IN MEXICAN ASTERACEAE

Chromosome numbers are reported for 100 collections distributed among 68 species and 46 genera of Mexican Asteraceae. Included are systematic discussions regarding chromosome numbers of the following taxa: Haplopappus spinulosus var. scabrellus (n = 4, 8); Hofmeisteria fasciculata (n = 19), Malperia tenuis (n = 10), and Pleurocoronis laphamioides (n = 9); Cymophora pringlei (2n = 16); Plummera (n = 15); and Porophyllum tridentatum var. crassifolium (n = 15) as related to Chrysactinia and Nicolletia.     

Chromosome numbers of miscellaneous Malagasy Acanthaceae

Meiotic chromosome numbers are reported for 12 species in eight genera of Acanthaceae from Madagascar. Chromosome numbers of 11 species are reported for the first time. Counts inMendoncia (n=19) andNeuracanthus (n=20) are the first for these genera. A new chromosome number (n=30) is reported inJusticia. Systematic implications of the chromosome counts are addressed and basic chromosome numbers for these eight genera of Malagasy Acanthaceae are discussed.     

Cytotaxonomical studies on AsianAnnonaceae

Chromosome numbers of 42 species and 3 varieties from 24 genera of theAnnonaceae have been determined (Table 1); reports for 15 of the genera are new. Among Asian genera 2n = 14 occurs only in the specializedMezzettia, while 2n = 16 is wide-spread and also has been found inAnaxagorea with some primitive characters. 2n = 18 is reported for 11 genera, and tetraploidy (2n = 36) has been observed inPolyalthia. Therefore, an original basic number of x = 8 or x = 9 is suggested at least for the Asian genera of theAnnonaceae.—Cytotaxonomical notes on the critical speciesPolyalthia rumphii andP. affinis are given, and the new combinationNeouvaria parallelivenia (Boerl.)Okada & Ueda is proposed.     

Karyological studies on some Antarctic liverworts

Abstract

Chromosome counts are reported from five species of Antarctic hepatics belonging to five genera and four families. The chromosome numbers in the genera Herzogobryum (H. teres n = 9) and Paehyglossa (P. dissitifolia n = 9) are reported for the first time. The first chromosome count from Lophozia excisa, n = 27, is the highest reported from Lophozia. A diploid number, n = 18, is reported for the first time from Barbilophozia hateheri; a second count, n = 9, agrees with earlier reports. The commonest Antarctic liverwort Cephaloziella cf. exili[lora has n = 18 and this agrees with earlier reports for the genus.