Scientifically known as Piper sarmentosum, this plant is one of the climbing herbs in the Piperaceae family. The genus name Piper is pepper in Latin, and sarmentosum refers to the long slender twigs of this species (Hussain et al., 2012). According to the Forestry Department of Peninsular Malaysia (2016), P. sarmentosum is mostly known as “kaduk’’or “kadok” in the Malay community.
Piper sarmentosum is widely distributed in Southeast Asia, where it is native to Malaysia, Indonesia, Thailand, Vietnam, Laos and Cambodia (POWO, 2022). It also occurs in coastal areas of southeast China (Sun et al., 2020) and in northeastern India (Waman et al., 2019). P. sarmentosum is mostly found in forested wet areas or near villages under shady trees. It usually grows very well understory, covering spacious ground. In Malaysia, this species is considered a weed because it can easily spread and grow wild (Syed Ab. Rahman et al., 2016; Fern, 2014).
This subshrub has alternate heart-shaped leaves and long, slender twigs, associated with long, creeping stems that are slightly hairy (Syed Ab. Rahman, 2016). The leaves are 7–15 cm long and 5–10 cm wide. The young leaves are light green and soon mature to a dark green. Typically, the leaves have waxy or glossy surfaces that enhance the species’ appearance. The flowers are small, rounded and white in the form of spikes (Corner, 1952). The spikes are usually located at the terminal of the leaves. The fruits are small, obovoid berries that mature to a deep green and taste sweet (Ng, 1989). Both fruits and leaves are edible.
Piper sarmentosum is often confused with Piper betle or “sireh” because both look similar with a slight difference between them. The latter is bigger with leaf size of 10-18 cm long and 5-11 cm wide. Even though the leaves of both species are aromatic and pungent, the taste is completely different (Chan & Wong, 2014). Piper sarmentosum has a slightly lemony taste, whereas P. betle tastes like mint.
Piper sarmentosum is a culinary plant whereby aerial parts of the plant are consumed as vegetables in various forms (Hussain et al., 2012). In some countries, the leaves are used to wrap food (e.g., grilled meat) and are often consumed raw as “ulam” in the Malay community (Chan & Wong, 2014). Besides, it is generally used as an essential ingredient in Thai and Lao cuisine. One of them is called “Miang Kham”, a traditional appetiser that looks like a salad bite combined with sour, sweet and salty flavours of other ingredients such as ginger, chillies, lime and dried shrimp (Wan Ibrahim et al., 2020). The leaves can also be added to curries or used to season food (Fern, 2014).
To date, the conservation status of this species has not been assessed, but is considered Least Concern because the species is common in the wild.
