Pinkies up! With upper pitchers like dainty cocktail glasses, Nepenthes inermis is a fascinating carnivorous plant with unique trap characteristics, including two (!) trapping mechanisms, that we explore in detail, below. First, let’s imbibe inermis‘ background:
On September 7, 1918, H. A. B. Bünnemeijer collected the first specimen of Nepenthes inermis from Mt. Talang. Found at an elevation of 7,500 feet (1,800 m) to 8,500 feet (2,590 m), inermis is squarely in highland Nepenthes territory. Bünnemeijer returned multiple times to collect additional N. inermis specimens, and it is the fourth specimen from Mount Kerintji collected on April 26, 1920 that became the lectotype, or species-defining plant exhibiting typical characteristics. Here’s a neat illustration published in the 1927 issue of De Tropische Natuur of Bünnemeijer’s first N. inermis herbarium specimen:
N. inermis was formally described one year after this publication by B. H. Danswer in “The Nepenthaceae of the Netherlands Indies.” He described the unique plant:
This new species is easily distinguishable from all others by the peculiar pitchers without peristome and with very narrow lid. Probably it is most nearly related to N. Bongso.
The written words “Galoe-galoe antoe” and “kandjong baroek” were found on a few of the original Bünnemeijer specimens. This was the name of the plant in the local Minangkabau language.
Nepenthes inermis grows on the Barisan Mountains on the western side of Sumatra in the Indonesian provinces of Jambi and West Sumatra. The largest populations are found on Mount Belirang, Mount Gadut, and Mount Talang and even Mount Gadang. Similar to N. veitchii, it has epiphytic tendencies (growing amongst or on trees) within mossy forests, but gravity wins above 6,600 ft (2,000 m) elevation where N. inermis has more terrestrial habits and grows alongside stunted vegetation.
Unique biology of Nepenthes inermis
Nepenthes inermis is commonly known for its unique upper pitchers. They are small, thin-walled, funnel-shaped, pure green, and significantly lacking in peristome. The name inermis comes from Latin, meaning “unarmed” – a play on the fact that upper pitchers are lacking a peristome. Suspended above the mouth of these 2 to 3.5 inch (5 to 9 cm) pitchers is a thin, filamentous lid. There is conjecture that the nectar secreted by this lid paralyzes feasting insects and causes them to fall into the upper portion of the pitcher.
The pitcher produces a thick, sticky, lubricating fluid that insects immediately stick to and then slowly slide down into the digestive juices at the bottom of the trap. In this way, N. inermis employs both pitfall and flypaper trapping mechanisms. The mucilaginous liquid is secreted from numerous pitcher-wall-lining glands and is so viscous that you can turn a pitcher upside down and pour it out like a stream of honey that will stretch multiple meters before breaking.
Pitchers don’t appear to have a waxy zone to prevent insect escape, instead relying on this fluid.
Other notable characteristics
Fun fact: because of how delicate they are and how little protection the lid provides, Nepenthes inermis pitchers frequently collect water and tip over during rainstorms. When this happens, the rainwater is dumped out, the viscous mucilage keeps sticking to pitcher walls, and the insects stuck to it remain intact. It keeps diner solidly planted against the pitcher wall for digestive purposes as the now-water-free pitchers spring back to their normal upright position.
N. inermis is a climber with stems reaching 23 feet (7 m) in length and internodes about 4 inches (10 cm) long. Leaves are short and narrow ending in tendrils about 6 inches (15 cm) in length. N. inermis rarely produces lower pitchers, but if you click through the images immediately above, you’ll find a couple of photos of these rarities. – Just look for the pitchers with a subtle green peristome.
Other Nepenthes species & hybrids
With unique domed pitcher shape and outwardly-facing mouth, Nepenthes aristolochioides is instantly recognizable, and with pitfall, lobster, and flypaper traps, the tropical pitcher plant is a jack of all traps. So beautiful, so deadly.
Nepenthes alata is a highly variable, widely grown, and hugely rewarding tropical pitcher plant. It's great for beginners looking to cut their teeth on an easy-to-grow and pitcher-prolific species.
A heavy-hitting lowland Nepenthes species with broad variability and even broader size. It was treasured by Victorian-era botanists for its beauty and it's easy to see why, even today.
To say Nepenthes ampullaria is unique, among a sea of unique Nepenthes, would be an understatement. The plant leans heavily on a vegetarian diet, playing host to critters that help it digest debris that falls from the forest canopy above.
Nepenthes albomarginata looks like it’s going on a date, all dressed up with a classy white collar. The characteristic band of white under the peristome serves a unique purpose, though - and it’s not for attracting the ladies or gents - rather, a specific type of prey.
Known as the "splendid pitcher plant" for good reason. It combines the most beastly characteristics of a flanged, spikey peristome with the handsome refinement of a cylindrical pitcher shape. It's like a lion in a tuxedo - it will bite your face off, but will do it with style.
Nepenthes robcantleyi x hamata
This gorgeous hybrid Nepenthes is what happens when you take two beauties, N. robcantleyi and N. hamata, and make a celebrity baby.
This tropical pitcher plant has black pitchers and a branched spur on the backside of where the lid and peristome meet. - Kind of like cowboy spurs, but less pokey.
Nepenthes lowii x truncata
This robust Nepenthes hybrid adopts the huge peristome of N. truncata pitchers and gaping mouth and lid of N. lowii. It's truly one beast of a tropical pitcher plant!
With knife-sharp hooks for a peristome, Nepenthes hamata is insect nightmare fuel and, hands-down, the most vicious looking tropical pitcher plant. If I were an insect, I'd refer to this as a Nope-enthes.
Ever imagine what would happen if a vampire bit a Nepenthes? Really? Me too! Well, wonder no more. Nepenthes bicalcarata is our fanged tropical pitcher plant.
Tropical Pitcher Plant
The Tropical Pitcher Plant, or Nepenthes, is an exotic and refined bug catcher. Some even grow large enough to catch small mammals.
The ol' toilet bowl for tree shrews. This tropical pitcher plant is famous for its odd upper pitchers that are not only shaped like toilets, but also act as actual toilets to climbing critters lucky enough to stumble across their secrets.
With upper pitchers like dainty cocktail glasses filled with honey, Nepenthes inermis is a fascinating carnivorous plant that uses both flypaper and pitfall trapping mechanisms.
With a peristome you can serve dinner off of, pitcher volume you can cary 2 liters of soda in, and a hunger that will decimate annoying insects, it's the perfect picnic guest
Translation of sanguinea is "blood red" - suiting name for a Nepenthes with pitchers so red that they almost appear purple.
Nepenthes x ventrata
The name is a combination of "ventricosa" and "alata," like "Brangelina" but with Nepenthes. Because it's easy to grow, popular in cultivation, and has a celebrity name, it's a star in my book.
is an extravagant, fuzzy tropical pitcher plant that hugs and climbs tree trunks as an epiphyte.
Nepenthes mikei Nepenthes mikei is a beautiful highland tropical pitcher plant discovered in 1989 by Bruce Salmon, Ricky Maulder, and Mike Hopkins on an expedition to Mount Pangulubao in Sumatra. The plant was first [...]
Nepenthes truncata A grand lowland Nepenthes, N. truncata is known to swallow entire rats whole. How can you tell? The smell, unfortunately. And the bones. They don't digest the calcium-heavy bones. Nepenthes truncata is [...]