Gymnosperm Database
Link to jump to start of content Home Topics Bookstore Links Site Map Contact Us

Search
Search the Database

photograph

Nageia nagi in Japan [Tom Velardi, 2004].

 

Valid HTML 4.01 Transitional

Nageia

Gaertn. 1788

Common names

Taxonomic notes

A genus of five species:

Syn: Decussocarpus de Laub. 1969. The genus was substantially reshuffled by Page (1989): N. falcata was moved to the new genus Afrocarpus; the new genus Retrophyllum received N. comptonii, N. minor, N. piresii, N. rospigliosii and N. vitiensis; and N. formosensis was split out from N. nagi. It is not clear to me that these changes necessarily increased our understanding of this group of podocarps (most of which were initially described simply as new species in the vast genus Podocarpus), but a conclusive understanding probably must wait for nucleic acid sequencing studies.

Description

David de Laubenfels (1988) described the genus sensu latu as "dioecious, erect shrubs or trees, 1-54 m tall. Bark tan to brown within and dark brown to black on the surface but often weathering to gray, peeling in irregular shaped plates to short vertical strips. Leaves opposite-decussate (or mixed with some leaves spirally placed), distinctly narrowed to a decurrent base. Juvenile leaves mostly larger than the adult leaves which are otherwise similar, twisted at the base so as to appear distichous, in most cases amphistomatic with the abaxial face uppermost on the left side of the shoot and the axial face uppermost on the right side (in a few species the leaves are hypostomatic and without this unique orientation). Pollen cones sessile or terminal, solitary or grouped, cylindrical (or oval). Each inverted seed completely covered by the fertile scale (epimatium), one or occasionally two subterminal on a scaly shoot, the usually persistent leathery covering becoming more or less fleshy when ripe."

Section Nageia, which includes the five species not reassigned by Page (1989), is described as follows:

"Erect shrubs or trees, 1-48 m tall. Bark smooth, on trees peeling in large thin irregular shaped plates with scattered lenticels. Foliage buds a compact cluster of lanceolate deciduous scales abruptly wider than the shoot and distinctly acute, when terminal often 2-3 mm beyond the last leaf bases, 3-6 mm long, lateral buds sessile. Primary shoots not differentiated from ultimate shoots. Leaves with many parallel vascular bundles (one of which is medial) converging towards the acute to acuminate apex, more or less elliptic but juvenile leaves very acuminate and adult leaves sometimes more or less blunt, distichous, amphistomatic with equal basal twists (or hypostomatic with opposite basal twists), narrowed to a short broad petiole. Fertile shoots arising in the axils of leaves from sessile buds essentially the same as foliage buds, one to several pairs of deciduous scales below the first pollen cone or the female receptacle. Pollen cones cylindrical solitary or grouped with one terminal and others forming sessile decussate pairs about 5 mm apart, each cone in the axil of a sterile scale but the terminal three often fused at their bases. In some species a part of the fruit-bearing shoot becoming enlarged and eventually fleshy forming a receptacle, otherwise a part of the shoot often remaining attached to the seed when it falls. Seed smooth, nearly spherical but elongated on the micropylar end into a small asymmetrical beak" (de Laubenfels 1988).

"Sterile specimens often confused with Agathis with very similar leaves, but in Agathis the parallel vascular bundles do not markedly converge towards the leaf apex and the terminal bud is globular, not acute but very blunt-rounded" (de Laubenfels 1988).

Distribution and Ecology

The five species are distributed from S India and Bangladesh across Indochina and Malesia to New Britain, and through S China to S Japan (de Laubenfels 1988).

Big tree

Oldest

Dendrochronology

Ethnobotany

Observations

Remarks

Citations

See also

Laubenfels, D.J. de. 1987. Revision of the genus Nageia. Blumea 32:209-211.

Last Modified 2012-11-23