Pedilonum malvicolor (Ridl.) Rauschert, 1983

Henry Nicholas Ridley describe this orchid in Results of an expedition to Korinchi Peak, Sumatra (Orchidaceae) 1917. In this book he describe 52 new species orchid from his expedition to Mount Kerinci in Sumatra.

H. N. Ridley places this in section Cuthbertsonia, but it is clearly a typical Pedilonum. Seemingly very close to Dendrobium hasseltii (Bl) Lindl. Liz Dauncey realised that the plant J. B. Comber found in East Java (p. 222 and p. 223, Orchid of Java) is not D. Malvicolor, but in is in fact a new species wich she has named Dendrobium stellare Dauncey, Harvard Pap. Bot. 7: 171 (2003).  
In year 1983 Rauschert transfer this species into porperly to be Pedilonum malvicolor (Ridl.) Rauschert, Feddes Repert. 94: 461 (1983).

Plant  
in tufts, 5-6 cm tall, the stem/pseudobulbs a litle zig-zag, somewhat clavate, the internodes 5-20 mm long.

Leaves
liniesr-lanceolate, more or less acute, apically bilobed, 1.2-3 cm long by about 5 mm broad.

Inflorescences
from the apical half of stems, wich are usually leafless at the time of flowering, the peduncle about 5 mm long, the rachis a little longer, bearing 1-3 (rarely more) flowers; floral bracts ovate-elliptic, spreading, 4.5 x 2.5 mm. 

Flowers
with thin, 1.5 cm long pedicels, pale magenta to bright lilac;

Dorsal sepal
elliptic, obtuse, about 12 x 5 mm;

Lateral sepal
triangular and acute, about 2 cm long by 7 mm broad, forming a 1.5 cm long mentum with their bases wich is curved and has a broad and obtuse base.

Petal
similar to the dorsal sepal.

Lip
spatulate, with eight nerves, claw narrowly linear, adnate to the sepals and column basally, higher up ovate, with an orange blotch in the centre, the nerves reddish towards the base, about 2 cm long by 5 mm broad towards the apex;

Column
orange, its foot pink, the stelids oblong, their filaments rather long.    

Collected originally from near the summit of Mount Kerinci near west Sumatra-Jambi boreder at 1590-3050 m, later found in other part of West Sumatra and from several location in the mountains of Aceh. Endemic.
(Orchid of Sumatra : 624, 2001 by J. B. Comber).

Recently specimen
Our specimen come from Mount Dempo in South Sumatra province collected in December 2012 and flowering during January 2013.
  

Homotypic Synonyms: 
Dendrobium malvicolor Ridl., J. Fed. Malay States Mus. 8(4): 90 (1917). 
Pedilonum malvicolor (Ridl.) Rauschert, Feddes Repert. 94: 461 (1983).

Pedilonum malvicolor (Ridl.)

Pedilonum malvicolor (Ridl.)

Pedilonum malvicolor (Ridl.)

Distribution: 
Sumatera
42 SUM


Lifeform: 
Pseudobulb epiphyte