摘要:

Forty‐one variations in calyx morphology and venation, stamen form, trichomes, style shape and aspects of habit and gross vegetative morphology were recorded for a cosmopolitan sample of 100Salviaspecies. Comparative data were subjected to computation under two fundamentally different programs,multclas(a mixed‐data method) andcentclas(taxonomically crude, strictly qualitative). The resulting classifications were essentially similar, but not identical; and inspection suggests that the differences result largely from taxonomic distortion inherent in thecentclasmethod.A classification of these Salvias is suggested, taken from themultclashierarchy, which is fundamentally different from anything yet proposed by taxonomists. Of the five subgenera, onlyCalosphacehas gained support; and of the twelve sections onlyHymenosphaceis homogeneous. The new scheme seems taxonomically reasonable, and is informative in that the groupings are consistent with observations other than those on which it was based. The main subdivision represents a distinction between Central and South American Salvias and the rest, and reflects variation in stylar morphology, though neither geography nor stylar form were subjected to computation. It is concluded that even OENTCLAS, used alone, could have greatly enhanced the taxonomic understanding of this well‐known

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00087.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Taxonomic and nomenclatural confusions encountered in a study of the British species ofCystoseiraare discussed; a number of non‐British species, problems of whose synonymy have become involved with those of the British species, are also included.Fucus concalenatusL. is shown to be a synonym ofF. foeniculaceusL. The combinationCystosira nodicaulis(With.) M. Roberts replacesC. granulata(L.) Grev., as the nameC. granulatais illegitimate and its type does not belong to this speoies.Fucus selaginoidesL. is the earliest description ofCystoseira tamariscifolia(Huds.) Papenf., but the combinationC. selaginoidescannot here be used since Naccari had earlier employed the name to described another species. The identity of the type specimenof Fucus barbatus L. and other descriptions of this species are considered.Cystoseira fimbriata(Desf.) Bory is the correct name for the species often referred to asC. abrotanifoliaCAg. The species currently known asC. discors(L.) Ag. has no legitimate name.Cystoseira iisneoides(L.) M. Roberts is shown to be the correct name of the species known asC. concatenataAg.Cystoseira selaginoidesNacc,C. sauvageauanaHamel andC. hoppiisensu Valiante are briefly discussed; the last has no legitimate nam

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00088.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The rhizome ofOleandra pistillarisand0. wallichiiis elongated (erect in the former, creeping in the latter), cylindrical, clothed with peltate, non‐glandular, hairy paleae and bearing leaves in small clusters separated by long leafless portions. The ground tissue of the rhizome is composed of thick‐walled parenchyma, and there is a peripheral sclerenchymatous sheath as well as a few scattered slender sclerenchyma strands in the pith close to the vascular cylinder. The vascular cylinder is dissected into a loose reticulum of slender meristeles by crowded, spirally arranged leaf gaps. In the ‘leafless’ portions of the rhizome these leaf gaps are associated with a solitary vestigial leaf trace: where well‐developed leaves occur, each gap is associated with two or three leaf trace bundles. In0. pistillaris, well developed leaves are in whorls at regular intervals; in0. wallichiithey are in small well‐separated groups, each group consisting of two to six leaves in two irregular rows on the dorsal surface (i.e. leaves all along the ventral surface are suppressed). Leaves in both the species are simple with an entire, free‐veined lamina and with an articulated stipe, the articulation being towards (but not at) the base and formed of an abscission pad. Branches of the rhizome are borne in pairs and each branch trace is a solitary cylindrical vascular strand, unaccompanied by any branch gap in the stelar cylinder. Sporangia are in circular sori placed in a row close to the midrib and protected by reniform indusia. The sporangial stalk bears glandular hairs, and is two cells thick except at the capsule base, where a short third row is developed secondarily during sporangial development as a protrusion from a lateral wall cell of the capsule base. The spores are of the bilateral type provided with a loose wrinkled perine: spinose excrescences occur over the exine as well as the perine. The prothallus is of the cordate type, bearing unicellular papillate hairs profusely on the surfaces and margin. It develops from a uniseriate germ‐filament which develops into a prothallial plate by longitudinal divisions in the anterior cells. The terminal cell of the germ filament ends in a hair either prior to or immediately after the initiation of plate formation. A meristematic cell is formed early, either as a daughter cell of the terminal cell or of the penultimate cell. On the basis of morphological comparisons it is suggested thatOleandrais probably allied to the Aspidioid rather than to the Dennstaedtioid or Lindsaeoid

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00089.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Cuttings ofTamarix aphyllawere grown in various concentrations of NaCl. Salt glands on newly developed branches were sectioned and examined, both with the light‐ and with the electron‐microscope. An electron‐dense material appears in cuttings grown in all concentrations of NaCl at the anticlinal walls of the innermost pair of secretory cells and, to some extent, on the surface of the gland above the cuticle. In the glands of cuttings grown in high concentration of NaCl this material also appears in large quantities, not only on top of the gland but also beneath the cuticle at the region of the median anticlinal wall of the outermost pair of secretory cells. The material beneath the cuticle is connected to the electron‐dense material on the outer surface of the cuticle via the secretory pores. It is suggested that this material is of pectic nature and forms a continuous system with the walls and wall protuberances of the secretory cells which are also very rich in pectic substances. As pectic substances absorb solutions easily they may enhance the transport of salt.Many proplastids, vacuoles with simple structure and others with infolded membranes as well as numerous mitochondria were observed in the secretory cells. In the walls between the collecting cells and the innermost secretory cells there are numerous plasmodesmata with characteristically arranged me

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00090.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00091.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00092.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Many pteridophytes are capable of two levels of selling, intra and intergametophytic. Since intragametophytio selling (the origin of both gametes from one gametophyte) results in zygotic homozygosity, this introduces a factor in pteridophyte evolution seldom contemplated. Morphological and genetic techniques are presented which may give an estimate of the frequency of intragametophytic selfing in nature.Morphological criteria such as the sequence of the development and the spatial arrangement of the gametangia may be indicative of the importance of intragametophytic selfing in the mating system. Estimates of the genetic load (sporophytio lethals) in a population are related to the frequency of the occurrence of intragametophytio selfing.Onoclea sensibilisL. morphologically has a mating system which gives a low probability of intragametophytio selfing. A genetic load was found in this species.

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00093.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

1The phenolic constituents of the monocotyledons are generally similar to those of the dicotyledons. Ellagic acid is, however, absent and the other ‘regular’ trihydroxy‐substituted constituents myricetin and leucodelphinidin are only rarely present. Leucocyanidin is also relatively uncommon.2The tendency evident in the dicotyledons for leuco‐anthocyanins and flavonols to be less frequently, and navones and methoxy‐substituted aromatic acids to be more frequently present in herbaceous than in woody plants is supported by the present data.3Glycoflavones, i.e. navones carbon‐carbon substituted with glycosyl residues, occur more frequently than in the dicotyledons, especially in the Gramineae, Iridaceae and Liliaceae. In the Iridaceae the glycoxanthone mangiferin is also frequently present.4In the last family, the generaCrocusandIrishave been examined in detail. InIris, where there is considerable morphological diversity, the chemical data support the recognized division of the genus on morphological grounds. InCrocus, where the division of the genus is less clear‐cut, there is corresponding difficulty in ascertaining distinctions on chemical grounds.5The bearing of the chemical evidence on possible phylogenetio relationships within the monocotyledons, and as between the monocotyledons and the dicotyledons

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00094.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The review summarizes the progress achieved in the revision of the Indian species of Commelinaceae and analyses how far the synthetic approach coupled with orthodox taxonomy has helped to clarify the many ambiguities prevalent in the family. Cytotaxonomic studies have definitely contributed to a proper understanding of such genera asCommelina, Cyanotis(sensu lato) andPollia, and also the various ‘species complexes’ in the above genera, though the evidence is not as forthright with reference toAneilemaandMurdannia.In the genusCommelina, polyploidy has played a rather prominent role in speciation, and intra‐specific aneuploidy is relatively of minor significance. The main evolutionary trend follows the pattern with predominantlyx= 15 for a majority of both the Indian and African species and even though a few African species do exhibitx= 14, this basic number is infrequent and at any rate not encountered in any of the Indian species analysed so far. In sharp contrast to this, in the genusCyanotis, both inter‐ and intra‐specific polyploidy is very much restricted, but judging from the recent trends both in Indian and African populations, intra‐specific aneuploidy has to be reckoned as a factor for further speciation within the genus. All the Indian species ofCyanotisanalysed so far share a common basic numberx= 12, but nevertheless there is an increasing evidence of secondary basic numbers such as,x= 8, 11 and 13 in at least a few random populations involving three species ofCyanotis. Moreover, both taxonomic and cytological data favour the splitting up ofCyanotis(sensu lato) into three distinct genera,AmischophacelusHolla Rao et Kammathy,BelosynapsisHassk. andCyanotisD. Don (sensu stricto).There is ample data to justify the separationof MurdanniaRoyle fromAneilema(sensu lato). The evolutionary trend inMurdanniaseems to follow two different patterns, one with a basic number ofx= 10 and the other withx= 6, both the patterns probably arising from a common extinct ancestor withx= 5. Preliminary observations on the Indian species ofAneilemaR.Br, (sensu stricto) suggest a basic number ofx= 14 (7?) in sharp contrast tox= 13, widely prevalent in a majority of the African species ofAneilema. InMurdanniaandAneilema, polyploidy and also aneuploidy are quite common and these two genera offer a fertile field for further study.There does not seem to be any justification for the separation ofAclisiafromPollia. InStreptolirion, intraspecific aneuploidy coupled with structural differentiation of chromosomes Seems to be responsible for further evolution of new varieties within the species. Cytological data favour the retentionof Floscopain tribe Tradescantieae rather than in Commelineae where Brückner has placed it.The various species complexes that had baffled the taxonomists especially inCommelina, CyanotisandMurdanniahave been critically analysed and their affinities clarified, on the basis of the present observations and study, 80 species under ten genera have so far been established, representing the Indian s

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00095.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

An intensive study of the cytology and sexual behaviour of the classicalSpartinaxtownsendiiagg. and their putative parents in southern England reveals a more complex chromosomal situation than had previously been reported, including aneusomaty in SouthamptonS. alterniflorapopulations and inS. xtownsendiiagg. Chromosome numbers are 2n= 60 and 2n= 62 forS. maritimaandS. alterniflorarespectively and 2n= 62 and 2n= 120, 122 and 124 (chromosome races) forS. xtownsendiiF1and Amphidiploid derivatives respectively. These numbers, though their summation is less precise than hitherto reported, still support the hybridity and amphidiploid origin ofS. xtownsendiiagg. and the process is further confirmed by meiotic pairing data and the discovery of wild backcross hybrids (2n= c.90and 2n=76) near the site of origin at Southampton. The 2n= 62 chromosome number ofS. alterniflora, out of line with thex= 10 base number of the genus, is explained as a polysomic condition (2n= 60+ 2) and needs further investigation with a study of North American populations.It is suggested that chromosome races found inS. xtownsendiiAmphidiploid will provide adaptive variation in this highly significant and successful amphidiploid.

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1968.tb00096.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY