Nepenthes macfarlanei is a carnivorous

Carnivorous plant

Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants appear adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic...

 pitcher plant

Pitcher plant

Pitcher plants are carnivorous plants whose prey-trapping mechanism features a deep cavity filled with liquid known as a pitfall trap. It has been widely assumed that the various sorts of pitfall trap evolved from rolled leaves, with selection pressure favouring more deeply cupped leaves over...

 species endemic to Peninsular Malaysia

Peninsular Malaysia

Peninsular Malaysia , also known as West Malaysia , is the part of Malaysia which lies on the Malay Peninsula. Its area is . It shares a land border with Thailand in the north. To the south is the island of Singapore. Across the Strait of Malacca to the west lies the island of Sumatra...

. It produces attractive red-speckled pitchers. Lower pitchers are ovoid to cylindrical and up to 20 cm high. The lower surface of the lid is densely covered with short, white hairs. This is a characteristic morphological

Morphology (biology)

In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

 feature of this species, but at present its function is unknown.

Natural hybrids

The following natural hybrids involving N. macfarlanei have been recorded.

• N. macfarlanei × N. ramispina
  Nepenthes ramispina
  Nepenthes ramispina is a highland Nepenthes pitcher plant species, native to Peninsular Malaysia. It is very similar to N. gracillma and there is much debate about whether the two should be treated as separate species.-Natural hybrids:...
  
  
• N. macfarlanei × N. sanguinea
  Nepenthes sanguinea
  Nepenthes sanguinea is a large and vigorous Nepenthes pitcher plant species, native to the Malay Peninsula, where it grows at 900–1800 m altitude. The pitchers are variable in size, from 10–30 cm tall, and range from green and yellow to orange and red. The insides of the pitchers are usually...
  
  

In Nepenthes of Sumatra and Peninsular Malaysia

Nepenthes of Sumatra and Peninsular Malaysia

Nepenthes of Sumatra and Peninsular Malaysia is a monograph by Charles Clarke on the tropical pitcher plants of Sumatra, Peninsular Malaysia, and their minor surrounding islands. It was published in 2001 by Natural History Publications...

, Charles Clarke

Charles Clarke (botanist)

Dr. Charles M. Clarke is a botanist and taxonomist specialising in the carnivorous plant genus Nepenthes. Clarke has an honours degree in Botany from Monash University in Melbourne, and a Ph.D. in Ecosystem Management at the University of New England, in Armidale, New South Wales.Clarke first...

 lists the natural hybrid N. gracillima

Nepenthes gracillima

Nepenthes gracillima is a highland Nepenthes pitcher plant species, native to Peninsular Malaysia.-Infraspecific taxa:*Nepenthes gracillima f. ramispina Hort.Westphal [=N. ramispina]...

× N. macfarlanei. At the time of the book's publication, N. alba was considered a heterotypic synonym of N. gracillima. Since then, however, N. alba has been elevated to a species. As both N. alba and N. gracillima occur on Mount Tahan

Mount Tahan

Mount Tahan , at 2,187 m, is the highest point in Peninsular Malaysia. It is located within the Taman Negara national forest, in the state of Pahang. The mountain is part of the Tahan Range and popular to local climbers....

, from which Clarke recorded the hybrid, it is unknown which taxon was involved in the cross.