Paphiopedilum roebelenii a.k.a. Paph. philippinense var. roebelenii
Habitat Information:

Geographic Distribution: Philippines island of Luzon, province of Rizal only.

Elevation: Sea level to 500 meters (Cribb:1997)

Blooming Season (North): April-June

Light requirements: Bright light, for a Paph. 3000 cf.

Temperatures : Intermediate to warm

Substrate: These grow primarily on limestone outcroppings along the coastal region of the island. The limestone creates a pH basic substrate, so this orchid will benefit from crushed oyster shell or dolomite lime added as a top-dressing to the growing medium when cultivated.

Water: There is no distinct dry season in Rizal province, and rain is common throughout the year. Regardless, the roots of roebelenii should not be soggy; evenly moist is ideal, and dryer is safer than wetter. Mineral content in the water is acceptable.

Humidity: High, 70%+, but good air-movement is critical.

Paph. roebelenii is very similar to Paph. philippinense, so much so that many do not recognize it as a separate species (Cribb:1987). However, it is easily distinguished from the typical philippinense bloom by its slightly larger flower and much longer, pedulous petals (about 5-6 inches long).

The spelling of this orchid's name seems to be an item of dispute. The most commonly seen spelling is "roebelenii". However, Jim Cootes, in The Orchids of the Philippines (2001) spells it "roebbelenii", stating that it was named after the original collector, Carl Roebbelen. Paph roebelinii is also a common spelling, or more likely, mis-spelling.