摘要:

Investigation of the fruits and seeds of the Oligocene (?) Brandon Lignite of west‐central Vermont (U.S.A.) is continued with a consideration of the seeds of the Magnoliaceae of the deposit. Following a review of the morphology of modern magnoliaceous seeds and a summary of the fossil record of seeds of the family, two new species are described:Magnolia septentrionalis, which is quite similar to the seeds of the extantMagnolia grandifloraof the southeastern United States, andMagnolia waltonii, which lacks a modern counterpart but is closely comparable to the seeds ofMagnolia lignitaof the European Mid‐Tertiary. The presence of two species ofMagnoliain this deposit supports the assumed warm‐temperate nature of the climate in Vermont during Brandon time. Diagnostic features for the description of the seeds of the Magnoliaceae are pro

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1977.tb01491.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The foliar sclereids in 136 species representing 11 of the 12 genera of Magnoliaceae were studied and compared. Sclereids occur in four different cell assemblages within the leaf: diffuse idioblasts, mesophyll, dermal system, and the vein sheath including terminal elements. Tropical members tend to have the most highly sclerified leaves. In species ofManglietiathe leaves have sclerified spongy mesophyll and either sclerified epidermis or hypodermis. InTalauma, sclerification affects the vein sheath and terminal cells of veinlets, with a specialized thick marginal vein in the Asian taxa but not in the American ones.Liriodendronand the magnolias native to the north temperate zone have only minimal sclerification, which usually is confined to the vein sheath of the midrib and the main lateral veins, and as idioblastic sclereids in the petiole and the midrib near the base of the blade. The two largest generaMagnoliaandMicheliaare heterogeneous and include species which vary as to their combinations of sclerified elements among the four possible types.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1977.tb01492.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The family Salicorniaceae J. Agardh is reinstated and includes 12 genera of succulent, apparently leafless plants formerly contained in the Chenopodiaceae. One of the genera is new and contains 15 species throughout the world, formerly placed in eitherSalicorniaorArthrocne‐mum.The remaining species ofSalicornia areplaced in 3 sections. The classification, origin and evolution of the family are discussed and the typification ofKatidiopsis, here reduced to a synonym ofKalidium, and the lectotypification ofArthrocnemumare examine

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1977.tb01493.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Anatomical characters of the mature leaf blade, petiole, young stem and wood were examined in order to substantiate taxonomic boundaries between genera and species of Theaeeae in Sri Lanka. Two species ofTemstroemia, one ofAdinandra, four ofEuryaand two ofGordoniawere studied.The presence of sclereids in most organs of the plant was found to be a common character within the family. However, three distinct types of sclereid are reported. Two basic types of stomata, anomocytic and gordoniaceous, are recognized. The origin of phellogen in the young stems is pericyclic inGordoniaand subepidermal in the other three genera. The species within these genera also appear to have several distinctive characters of their own. Important wood characters have been tabulated in order to illustrate the primitive and advanced characters.Gordonia, especially, exhibits anatomical features which are quite different from those ofTemstroemia, Adinandra send Eurya.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1977.tb01494.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY