Dacrydium comosum description

Conservation Status

Dacrydium comosum

Corner (1939)

Common names

No common names are recorded.

Taxonomic notes

Type: Malaysia, Malaya, Negeri Pahang, Pine Tree Hill, E. J. H. Corner SFN 33222 (holotype SING). Syn. Corneria comosa (Corner) A.V.Bobrov & Melikyan. Phylogenetics of this species seem not to have been investigated, but its distribution in peninsular Malaysia suggests a close relationship to D. beccarii and D. elatum.

Description

Shrubs, or small trees to 15 m tall and 50 cm dbh, typically with a single stem; on exposed ridges dwarfed and flat-topped. Branches spreading and ascending, making an umbrella-like crown with crowded, upturned foliage branches at the ends of the primary branches. Juvenile leaves and adult leaves very similar. Juvenile leaves spreading more perpendicular to branch, acicular, curved forward, very narrowly tapering, to 33 mm long, 1 mm wide at base, keeled abaxially, ending in a pungent apex. Adult leaves densely crowded and covering the shoot completely, spreading forward, acicular, straight or slightly curving outward, 12-20(-30) mm long, 0.6-1.2 mm wide at or just above a slightly widened base, 0.2 mm thick, flattened with a sharp abaxial keel, gradually tapering to a pungent apex. Amphistomatic with stomata on both sides in a few intermittent lines nearly to apex. Pollen cones mostly lateral on foliage branches, subtended by a few short leaves 4-5 mm long, 8-10 × 3 mm; microsporophylls terminating in a narrow extension, 1.5-2 mm long and 0.5 mm wide at base, with two basal pollen sacs. Seed cones few, terminal on short foliage branchlets, ca. 3 mm long, nearly hidden by leaves, with several lanceolate, colored bracts and 1(-2) exposed, ovoid, light brown seeds 4-5 mm long covered at base by the epimatium (de Laubenfels 1988, Farjon 2010).

Corner (1988) says D. comosum resembles D. beccarii but has "much longer needles, giving the twigs a woolly appearance"; twigs with sun foliage have leaves 12-19 mm long, while twigs with shade foliage have leaves 18-30 mm long. No other species of Dacrydium has both juvenile and adult leaves that commonly exceed 20 mm long, though D. xanthandrum comes close.

Distribution and Ecology

Malaysia: Malaya, "[K]nown only from the crest separating Selangor and Pahang and on the G. Tahan massif; Pine Tree Hill; Ulu Kali; Ginting Highland... On exposed ridges as a local dominant in stunted mossy forest between 1440 and 2200 m" (de Laubenfels 1988). Grows at elevations of 1170-2200 m on rocky acidic soil or shallow peat, usually on exposed mountain ridges as a local dominant in stunted mossy forest. Occasionally individuals are found in forest below the ridge and attain tree size to reach the canopy (Farjon 2010).

Distribution data for all species, from GBIF Occurrence Download https://doi.org/10.15468/dl.yvmru2, accessed 2025.12.08. D. comosum color is dark green. Click on any point for more info.

The IUCN (2025) reports that this taxon is endangered: "Extensive surveys of the flora of Peninsular Malaysia have resulted in the discovery of only five locations of this species. The extent of occurrence is 1,619 km² and the area of occupancy only 20 km². Four of these are situated within areas that have been highly developed for tourism hence there is continuing decline. This restricted occurrence increases the risk of disasters like fire even if the actual rocky localities themselves were not subject to further development." This assessment was performed in 2010 and needs to be updated.

Remarkable Specimens

No data as of 2026-01-10.

Ethnobotany

No data as of 2026-01-10.

Observations

It is reportedly a common species near the summit of Gunung Ulu Kali, 1758 m elevation (Chua and Saw 2001). Access is easy and the peak appears to be a popular hike.

Remarks

The epithet comosum means "having much hair", referring to long, pliable leaves.

D. comosum undergoes an extended period of seed dormancy, requiring both growth of the embryo to critical size and breakdown of physiological dormancy (Baskin and Baskin 2001). The advantage of this trait is not apparent; it plausibly may contribute to the species' rarity and limited distribution.

Citations

Baskin, C. C., and J. M. Baskin. 2001. Seeds: Ecology, Biogeography and Evolution of Dormancy and Germination. Academic Press, San Diego.

Chua, L. S. L., and L. G. Saw. 2001. A reassessment of the flora of Gunung Ulu Kali, Genting Highlands, Malaysia-preliminary findings and trends. Malayan Nature Journal 55(1/2):65-76.

Corner. 1939. Notes on the Systematy and Distribution of Malayan Phanerogams III. Gardens' Bulletin, Straits Settlements, Singapore 10:244, t. 10. Available: Biodiversity Heritage Library, accessed 2025.12.09.

Corner, E. J. H. 1988. Wayside Trees of Malaya, 3rd ed. Malayan Nature Society.

de Laubenfels, David J. 1988. Coniferales. P. 337-453 in Flora Malesiana, Series I, Vol. 10. Dordrecht: Kluwer Academic. Available: Biodiversity Heritage Library, accessed 2025.12.11.