REDISCOVERY IN SINGAPORE OF VRYDAGZYNEA LANCIFOLIA RIDL. (ORCHIDACEAE)

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Vrydagzynea lancifolia Ridl. was presumed to be nationally extinct until the rediscovery of a single individual in Bukit Timah Nature Reserve on 29 Oct.2013. Three inflorescences were observed on a single plant, but there was no fruit set. There were no other individuals found in the vicinity. Conservation is necessary to ensure the continued survival of this species in Singapore. A conservation status of critically endangered is proposed for this species. Description. — This is mostly based on the individual found in Bukit Timah Nature Reserve (BTNR). Vrydagzynea lancifolia is a terrestrial herb with branched, decumbent, grey-green stems each about 15 cm long with roots arising at the nodes in the horizontal portion in contact with the ground, ascending to the erect portion bearing about 812 leaves and terminating in an inflorescence (Fig. 1; Pedersen et. al, 2011). Internodes are about 1.6 cm long near the basal part of the erect stem portion, reducing to 0.4-0.5 cm long towards the tip, making the spirally arranged, stalked leaves appear crowded apically. The lanceolate leaf blades are 4.0-6.5 cm long and 1.7-1.8 cm wide, narrowed evenly towards the acute tip, with sheathed petioles of about 1 cm long. The leaf blades were observed to have slightly undulating margins and on the upper side, silver-grey longitudinal bands of about 1.0 mm wide on either side of the midrib (Fig. 2). The upper leaf blade surface is glabrous, while the lower leaf blade surface and the petiole are pilose (Fig. 3). The terminal inflorescence with more than 40 flowers (Fig. 4A) is 3.0 cm tall and 1.5 cm across, with a peduncle about 0.5 cm long. The inflorescence bracts are green, boat-shaped, and have margins bearing white hairs, sheathed bases, and acuminate tips. The flowers are resupinate, with the upper ones being held almost vertically. Each flower measures between 3.5-4.0 mm across, with several opening at a time from the base of the inflorescence upwards. Flowers, when fresh, have white petals and sepals with brown markings on the dorsal sepal, and all have their white parts maturing to yellow (Fig. 4B), fading to brown just before abscission. The flowers have narrowly ovate, c. 0.5 mm-long petals, c. 6 mm-long sepals, and an entire lip with a 4.0 mm-long spur. Contained within the lip of the spur at the base is a pair of stalked glands, each with a stalk 1.5 mm long and 0.8 mm across (Fig. 5) which are characteristics of the genus (Holttum, 1964; Seidenfaden & Wood, 1992; Keng et al., 1998). The column and rostellum is very short. Capsules are formed when flowers are pollinated, with the infructescence growing to 6 cm long (Fig. 6).

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