The two Physalis angulata (Bladder Cherry) plants that were sowed in late November 2024 in two separate pots have reached the end of their lifespan by the end of February. The plants' growth has ceased, as indicated by the yellowing leaves and lack of new growth. Flowering has also stopped. This week, the remaining parts of the two plants were removed to make space for other plants. Upon cutting down the plants, it was observed that their stems and main branches were hollow. The fibrous root system is relatively shallow, making the removal from the soil easy.

I was surprised to observe that the lifespan of the plant has been relatively short, only about three months. Despite this, the plant has produced numerous “lantern” fruits. To better visualize the arrangement of the seeds within the fruit, I removed the papery husk (calyx) from one of the fruits and made a cross-sectional cut of the exposed berry (Fig. 1), rather than opening it by force as demonstrated in my previous post in January. Coincidentally, I also had a fruiting Solanum americanum (American Black Nightshade) in my pot, which produces berries as well. Thus, I decided to perform a cross-sectional cut on its ripe purplish fruit for comparison (Fig. 2). The diameters of the berries of Physalis angulata and Solanum americanum are approximately 10 millimetres and 5 millimetres respectively.

Fig. 1: Fruit and seeds of Physalis angulata		Fig. 2: Fruits and seeds of Solanum americanum

Both Physalis angulata and Solanum americanum belong to the Solanaceae family. Furthermore, both species can be found in the wild in Singapore. However, according to my experience cultivating these plants, Solanum americanum has a significantly longer lifespan, exceeding one year. A review of observations on the iNaturalist website on 16 March 2025 reported 33 observations of Physalis angulata and 7 observations of Solanum americanum, indicating that Solanum americanum is evidently rarer than Physalis angulata.

I reviewed the listing of the Solanaceae family in the latest Singapore flora checklist. Eight species are listed (Table 1). This is fewer than the 19 species listed in the earlier version published in 2009. The latest checklist has omitted all cultivated species. Of the eight species, four (Solanum americanum, Solanum lasiocarpum, Solanum torvum and Solanum trilobatum) are classified as “naturalised” in Singapore. There have been no personal encounters with Solanum lasiocarpum and Solanum trilobatum so far. The iNaturalist website has one observation of Solanum lasiocarpum in Singapore from August last year at the Tanglin area. Currently, there is no record of Solanum trilobatum from Singapore.

Fig. 3: Seedlings of Solanum americanum from the bird poo; (from left to right) 5-, 8- and 24-day old seedlings

About a month ago, while observing the excrement left by a bird on my balcony, I noticed several small seeds within it. To determine the parent plant of these seeds, I carefully collected them and placed them in a pot. Based on the appearance of the seedlings, they are likely Solanum americanum (Fig. 3). My sole Solanum americanum plant is also nearing the end of its lifespan. I intend to replant two seedlings into the pots that previously housed Physalis angulata.

Given the relatively short lifespan of Physalis angulata, I have decided not to continue cultivating it for the time being, as I have already harvested numerous fruits. If necessary, I can always propagate another plant from the seeds stored in the berries.