There's also Rafflelesia in the Temenggor lake area in Northern Perak. Accessibility is very limited unless you have a guide that have a boat.
I went with through this eco-tourism company.
http://www.geocities.com/greenvillagemalaysia/3D2N - stayed in Pulau Tikus, a rat shape island with very basic amenities (N5 41.479 E101 20.89). Most of the activities are done with boat rides along the man made lake, going from seeing these giant flowers, wild bee hives, elephant salt lick, natural hot spring, hornbill watching, Negrito village visitation, dam visit, caves.