Podocarpus rostratus
None are known.
Type not designated. No synonyms, but De Laubenfels (1985) and Eckenwalder (2009) synonymized this species with Podocarpus perrieri Gaussen & Woltz. Farjon (2010) restored P. perrieri to species rank, citing Gaussen's (1976) discussion of leaf anatomical characters (also explained by Gray 1953), and later authorities have followed suit. To date, the question has not been investigated using molecular taxonomy.
There are, in this treatment, 5 species and 2 varieties of Podocarpus on Madagascar, all endemic. They all belong to subgenus Podocarpus, section Scytopodium (de Laubenfels 1985). The only molecular taxonomic work to consider this group is the Podocarpaceae-wide molecular and morphological study by Knopf et al. (2012), which considered 2 of the 7 taxa (P. capuronii and P. madagascariensis var. madagascariensis) and assigned them to a clade shared with all of the African species. Leaf cuticle micromorphology has also proven to be a useful source of taxonomic characters in Podocarpus, and the analysis by Stockey et al. (1998), considering all Madagascar taxa of Podocarpus, found them very similar. P. perrieri and P. rostratus were found to be particularly similar, as they are in macromorphological characters as well. They are currently recognized as separate species, due largely to their disjunct distributions, but both are still known from very few collections, and the morphological data support a sister relationship between the two taxa.
Usually stunted trees, but up to 10 m tall. Bark exfoliating in small strips and flakes, light brown weathering to gray. Twigs slender and round. Foliage buds ovoid-globose with imbricate, apiculate scales. Leaves somewhat dimorphic; on mature trees sessile, straight or slightly falcate, linear, 15-30 × 1-2 mm, margins entire, upper midrib absent or inconspicuous or a shallow central groove, lower midrib flat or bluntly raised; leaves on juvenile plants up to 60 × 3 mm. Pollen cones axillary in 1's and 2's on 1-6 mm pedicels, 10-15 × 2.5-3 mm, microsporophylls with a 1 mm long rostrate apex. Seed cones axillary, solitary, pedunculate, subtended by two 1 mm spreading or recurved bracts; receptacle cuneate, 3-4 × 2-4 mm, with a solitary ovoid seed 14 × 8 mm within the epimatium, with a small crest below the apex (Farjon 2010).
The very narrow leaves, 1-2 mm wide, distinguish P. perrieri and P. rostratus from all other Madagascar podocarps. Between the two species, P. perrieri has obtuse or acute foliage bud scales, leaves 7-20 mm long, and small seeds (8 × 5 mm). P. rostratus has apiculate foliage bud scales, leaves 15-30 mm long, and large seeds ca. 14 × 8 mm (Farjon 2010).
Madagascar: Antisiranana, Fianarantsoa, Mahajanga, and Toamasina Provinces, where it has been found at elevations of 1800-2400 m on silicate rocks in ericaceous shrublands near mountaintops. Such sites are prone to wildfire, and the species is not well adapted to fire, so it mainly occurs on sites with very little vegetation cover, or on wet sites such as along streams (Farjon 2010).
Distribution data for all species native to Madagascar, based on identified specimens listed by GBIF (2023). Each point includes a link to more data and, in most cases, an image. Podocarpus rostratus shown in brown.
The IUCN reports that this species is in decline. It is primarily known from only 3 highly disjunct populations with a total area of occupancy of less than 175 km2. Moreover, the eastern and southern subpopulations (over 1,000 km apart) are documented from collections made in 1924-25 at locations which have probably since been cleared. Serious decline of small subpopulations is inferred for this species, which is susceptible to fires (Farjon 2013).
No data as of 2023.02.05.
No uses are reported (Farjon 2010).
See the map shown above.
The epithet is from the Latin rostrum, a beak, and refers to the beaked apex of the microsporophyll.
Farjon, A. 2013. Podocarpus rostratus. The IUCN Red List of Threatened Species 2013: e.T34096A2845405. https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34096A2845405.en, accessed 2023.02.05.
Laurent, L. 1915. Les Podocarpus de Madagascar. Annales de la Faculté des Sciences de Marseille 23:52-64 (p. 60).
Stockey, Ruth A., Brenda J. Frevel, and Philippe Woltz. 1998. Cuticle micromorphology of Podocarpus, subgenus Podocarpus, section Scytopodium (Podocarpaceae) of Madagascar and South Africa. International Journal of Plant Sciences 159(6):923-940.
The species account at Threatened Conifers of the World.
Last Modified 2023-02-26
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