SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Laubenfels, D.J. de; Adema, F..

The genus Cycas L is divided into four subgenera, all new, and thirty species are described, of which two are new. A new Asian genus, Epicycas de Laub., is recognized for several Cycas species and one undescribed species with a subterranean bulbous stem base. Keys to the subgenera of Cycas and their species, and to the genus Epicycas are given.

Distribution maps of Pacific plants

Palavras-chave: Cycas; Epicycas; Morphology; Taxonomy.

Ano: 1998

URL: http://www.repository.naturalis.nl/record/525403

Avé, W.; Balgooy, M.M.J. van; Franken, N.A.P.; Roos, M.C.; Hoogland, R.D.; Veldkamp, J.F.; Laubenfels, D.J. de; Jansen, M.E.; Vink, W.; Kessler, J.J.; Haegi, L.; Symon, D.E..

Name: Campynema Labill, Nov. Holl. Pl. Sp. 1 (1805) 93, t. 121. Family: Amaryllidaceae.

Revision of the genus Nageia (Podocarpaceae)

Ano: 1984

URL: http://www.repository.naturalis.nl/record/509482

Because of changes in nomenclature rules the species previously included in Decussocarpus are moved to Nageia.

Ano: 1987

URL: http://www.repository.naturalis.nl/record/525942

Araucariaceae

Monoecious, medium-sized to very large trees (rarely shrubby in very exposed situations). Either four independent cotyledons or two fused pairs (which may be retained in the seed after germination). The growing point of foliage shoots quite distinct between the two genera, being just a few highly reduced leaves in Araucaria and a highly organized bud formed of overlapping scales in Agathis. The leaves vary from scales or needles to broad leathery forms with many parallel veins sometimes on the same plant at different stages of growth. Pollen produced in cylindrical cones from one to as much as twenty cm long with numerous pedunculate spirally placed microsporophylls each with several to many pendent elongated pollen sacs attached to the lower side of an...

The pollen cone of Falcatifolium papuanum De Laubenfels (Taxaceae)

Ano: 1984

URL: http://www.repository.naturalis.nl/record/532694

Recent collections in New Guinea (Havel and Kairo NGF 17342) have brought to light the hitherto unknown pollen cone of Falcatifolium papuanum de Laubenfels (J. Arnold Arb. 50, 1969, 312). These cones are of interest because of their small size, particularly compared to the other species of the genus where the pollen cone usually reaches several centimetres in length. The fully mature cone of F. papuanum is c. 5 mm long and 2 mm in diameter. It appears both in terminal and lateral positions; when terminal it is subtended by a few sterile scales, when lateral by a larger number.

Ano: 1969

URL: http://www.repository.naturalis.nl/record/526129

Podocarpaceae

Monoecious or dioecious trees and shrubs, some prostrate (and one parasitic on another member of the family, Parasitaxus, in New Caledonia). Each cotyledon, of which there are usually two but in a few cases more, a fused pair with a corresponding bifid tip. Foliage buds ranging from a loose cluster of reduced leaves to a complex specialized structure (in Podocarpus). Leaves of many shapes and sizes. Pollen produced in small cones with many microsporophylls, each of which have two inverted dorsal pollen sacs above which is a small sterile tip. Male cones may be solitary in the axils of ordinary leaves, sometimes many adjacent cone subtending leaves, or they may be terminal or clustered on special structures involving sterile scales, or in a few cases they...

A taxonomic revision of the genus Podocarpus

Ano: 1984

URL: http://www.repository.naturalis.nl/record/532614

In connection with the forthcoming revision of the Coniferae for the Flora Malesiana, the author thought it necessary to revise the genus Podocarpus. Although this genus has a substantial representation in Malesia (30 species), the revision is too involved to be appropriate with the Flora Malesiana per se. One new subgenus and 17 new sections are described, and 94 species are enumerated, of which 11 species and 1 variety are described as new, and 3 varieties have been raised to specific rank. Two keys are given to the 18 sections; each section has a key to the species.

Ano: 1985

URL: http://www.repository.naturalis.nl/record/524516

Pinaceae

The pine family is one of the most characteristic families of the holarctic realm of which family a few genera reach the margins of the tropics in highlands, but only Pinus extends into tropical lowlands including Malesia.

Ano: 1984

URL: http://www.repository.naturalis.nl/record/532560

Cupressaceae

Both Cupressaceae and the closely related Taxodiaceae are important Holarctic families which also have representatives in the southern hemisphere. A few species of both extend into habitats on the margins of the tropics or into tropical highlands. Of 18 genera of Cupressaceae only Libocedrus reaches into Malesia. Occasional reports of Callitris in New Guinea have been based on similar appearing specimens of Casuarina.

Ano: 1984

URL: http://www.repository.naturalis.nl/record/532508

Taxaceae

The affinity of Taxaceae has been much debated, with many authors favouring a separate order, Taxales, for it, a position with which I tend to agree. Further questions are raised concerning the grouping of other families with Taxaceae, as against the other conifer families, based on the lack of seed cones, fleshiness of the mature fruit, or lack of a fertile seed scale. Cephalotaxaceae (not in Malesia) has a reduced seed cone structurally organized quite differently from other conifers and vegetatively strongly resembling Taxaceae, so I would group these two together. All other conifer families show seed structures easily derivable from a compound cone with ovules produced on the upper face of a fertile scale which grows in the axil of a bract. Although...

Ano: 1984

URL: http://www.repository.naturalis.nl/record/532519

Coniferales

In spite of generalized impressions sometimes advanced about the decline and decrease of the Gymnosperms through the enormous development of the Angiosperms in the Cretaceous and their rapidly accelerated development in the Tertiary, it must be realized that this impression is confusing as far as Coniferales are concerned. It is of course a truism that the Gymnosperms are completely outnumbered in genera and species by the Angiosperms, the latter occupying terrain earlier beset by Gymnosperms. It must be realized, however, that possibly the almost entirely woody Gymnosperms did never have the potential for producing such immense numbers of genera and species as now found among the Angiosperms. This statement is also valid for the Coniferales.