Observation Series
Growing Black Nightshade

I started drafting this piece of work on the Black Nightshade back in October 2012 but did not publish it in my website until January 2013. When I stated the draft, I thought that this plant was Solanum nigrum, commonly known as the Black Nightshade. After a more thorough research on the on this herb, I started to doubt its current identity. Firstly, the name Solanum nigrum was not listed in the Singapore flora checklist published in 2009 [1]. However, the name Solanum americanum was in the checklist and its appearance looked similar to my pictures of this herb. When I thought I had finally got my answer, I came across an article that questioned my new found knowledge. According to this article published in 2007 by Manoko [2], the herb that I saw was more likely to be Solanum nodiflorum.

photo photo My special interest on this herb was triggered when someone wrote to me in May 2012 with great urgency to obtain it. Unfortunately, I was not able to help then. This is a rather illusive and rare herb in Singapore, where you will never know exactly where to find it. Usually, it sprouts spontaneously on newly cleared land where the top layer of the soil has been tilled. But, it is no match to many other wild herbacious plants. As soon as the other plants start to occupy the land, it vanished. In April 2010, I saw a lone plant growing in a pot. It did not look likely a cultivated one but rather one from a spontaneous growth. There were some flowers but no fruits. I had no clue how the tiny seeds in the berries get dispersed.

photo photo Nearly a year later in February 2011, I found a few of this herb at a newly cleared land in a park. There were at least 3 matured plants with flowers and fruits. The fruits were still green when I first encountered the colony. When I returned a month later in March, the ripe black berries were ready for harvest. At that time, I did not have the urge to collect the berries since I had no intention to grow it. Since then, I had not seen the herb until October 2012.

This time round, it was a single plant with flowers, ripe and unripe berries located again in a newly cleared land by the side of a forested area. Recalling that someone was anxiously looking for it in May, I was then interested to grow this herb and picked 2 bundles of the ripe berries. Before this collection, I had approach someone who grow herbs to attempt to obtain a plant but was told that this herb is difficult to cultivate. He had not success yet in growing one.

Back home, I dissected 2 berries. The berries contained fleshy pulp where the tiny seeds were embedded. Each berry had around 32-36 tiny seeds. The dark purple colouration of the ripe berries was confined to its skin while the fleshy pulp surrounding the seeds was actually light green in colour. Since I was had no idea on their survival rate, I placed 4 seeds in each small plot of the cultivation tray. A total of 48 seed were sowed. A week later, 20 seedlings appeared ----- less than half of the seeds sowed.

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The growth of the seedlings seemed to be rather slow. Two weeks later, there were still only 2 tiny leaves. I was worried that the seedlings might not continue to grow. They seem to be rather fragile and not much growth was seen in the past one week.

photo photo photo Meanwhile, the leftover berries had shrunk in size due to the loss of water content in the berries. I sliced opened another 2 of them. There was no more sticky pulp as it had dried up. In all, over 70 seeds were collected and kept in a sealed container for future use.

I was concern that the depth of the soil in the cultivation tray might be too shallow and the sunlight condition might not be optimal. I decided to move all the seedlings to a bigger pot located at my balcony with direct sunlight. During the move, 3 seedlings did not make it which then reduced the surviving count to 17.

photo photo photo Surprisingly, more seedlings appeared in the bigger pot bringing the total number to 42, which means that only 6 out of the 48 seeds did not make it. Three weeks later on 26 October 2012, the third leaf was visible in some of the seedlings. By 31 October, some seedlings had as many as 5 leaves.

The growth of the young plants accelerated over the next few weeks which made the tiny land very crowded for over 40 plants. At the end of November, I started to move a few plants to some other pots but was not able to find enough space to relocate all of them. As expected, these relocated plants thrived well while those that stayed in the crowded pot looked malnourished.

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To cut the long story short, the first bundle of flower buds appeared on 22 December 2012 and eventually, the long awaited ripe purplish berries arrived on 21 January 2013. In all, it took nearly 3.5 months or 14 weeks from seeds to berries. After all, it was not too difficult to grow this herb.

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Soon, 2 types of pests, namely mealybugs and white flies started to invade this herb. Both pests positioned themselves on the underside of the leaves. The mealybugs were transported around the plant by ants while the white fly colonies appear as white patches under the leaves.

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I had collected the ripe berries from my own cultivation and might continue to grow them in the future.

Reference:

(1) Chong, K. Y., H. T. W. Tan & R. T. Corlett, 2009. A Checklist of the Total Vascular Plant Flora of Singapore: Native, Naturalised and Cultivated Species. Raffles Museum of Biodiversity Research, National University of Singapore, Singapore. 273 pp. | Read article |

(2) Manoko, M. L. K., R. G. van den Berg, R. M. C. Feron, G. M. van der Weerden & C. Mariani, 1997. AFLP markers support separation of Solanum nodiflorum from Solanum americanum sensu stricto (Solanaceae). Plant Systematics and Evolution 267: 1-11.

Last updated: 26 January 2013

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