Syncolostemon comptonii Codd
Information extracted from Donald McCallum's unpublished thesis.
Syncolostemon comptonii Codd.
Description: Shrub to 160 cm tall; stems slender, shortly hairy. Leaves appear clustered at nodes, oblanceolate to narrowly elliptic, 2 – 3.5 x 0.3 – 0.6 cm; apex acute; margin entire; petiole short. Inflorescences compact with 2-flowered verticillasters spaced 2 – 3 mm apart. Corolla white, 9 – 10 mm long.
Distribution: This species is known only from one area in Swaziland. The type was collected near Komati bridge in 1959 (Codd, 1976). By the time the name was published a new shorter road had been built to Piggs Peak, and the new Komati bridge was 2 km downstream from the old bridge. The old bridge is near an ultramafic site, and the old road crosses ultramafic rock on the ascent out of the Komati valley on the way to Piggs Peak while the new road is on granite for the entire transit of the valley. Superimposing the geological map on the map of the old road and marking positions of the three specimens at the National Herbarium (PRE) and the one collected in the present study it is found that all specimens were collected on ultramafic soils. This taxon is probably uncommon in the localities where it occurs. Added to this the serpentine sites are small in extent and remote from the present road so little if any collecting is likely to have occurred at these localities. Anyone wanting to relocate populations of the plant could easily have searched in vain near the present road. The paucity of vouchers for this taxon is probably due to a combination of the very localised distribution and probably small populations.
Discussion: This species closely resembles S. parviflorus E. Mey. ex Benth. which also occurs in the area. D. Otieno (pers. comm.) considers the species to be so close that S. comptonii should perhaps be recognised as a variety of S. parviflorus rather than at species level. The close resemblance and presence in the same area suggest neoendemism.
IUCN Red List assessment: The infrequent collection of this species can be explained by:
- The limited extent of possible habitat.
- The change of route of the road which probably occurred before or shortly after the species was described in 1976.
- An extensive area where it was previously collected (Komati Pass) is now under plantation.
- It being uncommon where it does occur.
The present classification in Golding (2002) is critically endangered (CR A1cB1B2a) but that classification is partly based on incorrect information. The Maguga Dam threatens the area around the Komati bridge on the present Mbabane – Piggs Peak road, not the area where the plant was actually collected at the previous Komati bridge, upstream of the dam.