摘要:

When grown under a variety of axenic conditions gametophytes ofE. arvense, E. telmateia, E. sylvaticum, E. palustre, andE. fluviatileare all morphologically distinct. Lamellae from archegonial branches provide several diagnostic features but lamellae associated with antheridia are much less distinct. The archegonia of all five species have two neck canal cells and three tiers of neck cells and are of limited use taxonomically. Although antheridium development is basically similar in all species, during the metamorphosis of the spermatocytes specific differences arise in the shape of the cavity, degree of emergence and the number of opercular cells. A taxonomy of the gametophytes based on antheridium morphology corresponds very closely to the classification of the subgenusEquisetuminto three sections based on the coning behaviour of the sporophytes.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1973.tb02157.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

A study of the development of the gametophyte of 16 thelypteroid ferns from Jamaica reveals similarities and some differences among them which may have some bearing on their taxonomic position. They all possess a hairy, relatively long‐lived thallus which at maturity is cordate, relatively delicate for its size, with a wide cushion, broad wings, abundant colourless or pale tan rhizoids and sex organs of the advanced type. Although spore ornamentation, length of gametophytic simple hair and form and dehiscence of the antheridium are features which differ among the species, two gametophytic characteristics set apart the goniopteroid representatives: a branched hair and the development of the cell plate from subterminal cells of the germination filament when the filament ends in a hair. The presence of these with other minor and inconsistent differences suggests a not very close relationship ofGoniopteriswithMenisciumand supports those authors who prefer generic distinctio

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1973.tb02158.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Leaves of 344 species of the Ericaceae and of 37 species in three related families have been surveyed for flavonoids and simple phenols. The yellow flavonol gossypetin was found in 158 ericaceous species and is of chemotaxonomic interest within the Rhododendroideae (where it occurs in 11 of 19 genera) and in the Vaccinioideae (in 3 of 22 genera). 5‐0‐methylflavonols appear in 81 species, again mainly in the Rhododendroideae (eight genera); whereas 3,5‐di‐O‐methylquercetin, caryatin, is present only inBejaria, PhyllodoceandRhododendron.Dihydroflavonols. common inRhododendron, show a sporadic distribution elsewhere in the family. Of the simpler phenols surveyed, gentisic acid is common but methyl salicylate is present mainly inGaultheria.Hydroquinone appears in ten related genera, methylhydroquinone in three and orcinol in seven. The chemical evidence generally supports Stevens' recent classification of the family, particularly his inclusion ofEpigaeain the Rhododendroideae and his transfer ofDiplarchefrom the Diapensiaceae to the Ericaceae. There is also chemical evidence to support the separation ofCallunaandCassiope, the inclusion of the Aibutoideae within the Vaccinioideae and the retention of the Pyroloideae and Monotropoideae within the Ericaceae. In addition, chemistry indicates thatPhyllodoceshould be placed nearer to the Rhodoreae than in Stevens' system and thatCassiopeandHarrimanella, placed together in the Cassiopeae by Stevens, are distinctly

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1973.tb02159.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Carpels inChoisya, Rufa, PoncirusandCitrusare peltate. InCitrusthe style contains as many isolated canals as there are carpels, and these canals are shown to be bounded by the morphologicallyouter(lower) surface of the carpel. All instances exhibit an at least incipient syncarpy, and the floral axis is always involved in the central merging of the carpels. This is especially obvious here on account of vascular anatomy. Both peculiarities are probably much more widespread than is generally allowed; some other examples are afforded. The axis of the flower is certainly the same as that of the vegetative portion of the plant, and Meeuse's concept of a pseudo‐axis in the flower cannot apply her

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1973.tb02160.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

The two genera of Buxbaum's tribe Wurmbaeae,AnguillariaandWurmbea, have multiovulate carpels. There are deep septal indentations between the carpels ofAnguillaria, but the wings of adjoining carpels are fused to solid septa in most species ofWurmbea.InAnguillariathe carpels have open sutures or prominent commissural markings; inWurmbeathe carpels generally lack these characteristics, and some species have a vascularized, columella‐like axis in the centre of the pistil. In both genera there are a dorsal bundle, lateral bundles, and two placental bundles in each carpel. At the inner edge of the septum there are one or two septal bundles inAnguillariaand one or none inWurmbea.The ovules are monotegmic, the integument and funiculus being partly fused inAnguillariaand mostly fused inWurmbea.An obturator is present inAnguillariabut absent from most species ofWurmbe

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1973.tb02161.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Vegetative branch buds ofC. lutescensare non‐axillary and occur within an abaxial, tubular extension of the leaf sheath, either at the base of a shoot or aerially, a position unusual for palms. Buds are initiated on theabaxialsurface of a leaf during its first plastochron (the youngest leaf primordium). The foliar origin of the vegetative bud appears to be unique for angiosperms. In contrast, inflorescence buds are axillary and are initiated as an adaxial ridge on the base of a leaf during its third plastochron (the third primordium from the apex). Aerial branches and basal suckers are developmentally identical and changes in their phyllotaxis are described. As far as can be established by comparative morphology, other species ofChrysalidocarpushave the same type of branch development as inC. lutescens.The development of branches is related to the morphogenetic characteristics of arborescent monocotyledon

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1973.tb02162.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1973.tb02157a.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY