Weekly Series
Nature Weekly
Short Notes on Nature Singapore

22 November 2020 | Two New Plants | Southern Sandbur | Flaxleaf Fleabane |

photo photo I finally got to add the pictures of Southern Sandbur (Cenchrus echinatus), a member of the Grass family (Poaceae), to my website after seeing pictures from others online taken in Singapore. During an evening walk in late October, I found a few plants growing at both side of a pedestrian walkway beside a road. Some plants already had fruiting stalks, the feature that caught my attention. The soil had been tilled recently due to road expansion while the walkway was re-constructed.

The next day, I went back to the location with my camera and collected 2 fruiting stalks. I will try to grow them in my pot to allow me to take some pictures of its young plant. The dried fruit, known as bur is covered with hooks that help it to stick to any creatures that come into contact with it, thus helping with the dispersion of the seed.

When I did a check in the iNaturalist website today, there were 850 observations reported on this grass. Two observations were in Singapore, at Changi Beach Park on 30 January 2020 and East Coast Park on 6 September 2020. Both reported by the same person. This grass species was first collected in Singapore in 1994 according to the Gardens' Bulletin published in 2004 [1]. Another similar-looking grass, Cenchrus brownii was first recorded here in 1950 but I had yet to see one.

photo photo Separately on 14 November, I came across another new plant or should I say took the pictures of a new plant since I had seen it in the past but not able to take its picture. This one was from the Sunflower family (Asteraceae). It was growing on the soil located between a walkway and a concrete wall. At a first glance, it looked like a larger version of Cyanthillium cinereum (Little Ironweed), with larger leaves and taller in height. I searched the Asteraceae pictures in NParks' Flora & Fauna Web but nothing came close. Then, I screened through the listing of plant species in the Asteraceae section in the 2009 Singapore plant checklist. This was where I found the name Conyza bonariensis.

Conyza bonariensis was listed in a 1997 publication on a botanical survey done at Sungei Buloh Nature Park [2]. Besides the listing of the names, I was not able to find a single picture of this plant online from Singapore. The Plant List website had listed Conyza bonariensis as a synonym of Erigeron bonariensis (Flaxleaf Fleabane or Hairy Fleabane).

When I checked the iNaturalist website, there were 3,578 observations of Erigeron bonariensis around the world as of today with no report from Singapore. There was a single report from Malaysia but that lone picture looked more like a Tridax procumbens (Coat Button). Another similar-looking plant was Erigeron sumatrensis (Tropical Horseweed). It had 2,694 observations in iNaturalist website as of today. Again, nothing from Singapore but there were 4 observations in Malaysia with the closest one in Johor. All of the pictures did not showed any flowers, just leaves. One of the picture was actually a Dracaena fragrans (Corn Plant).

This was the second Erigeron species in my website, the first one being Erigeron bellioides (Bellorita).

References:

[1] Duistermaat H. New grass (Poaceae) records for Singapore, including Panicum laxum new for Asia. Gard Bull Sing 2004;56;29-42.

[2] Tan HTW, Choong MF, Chua KS, Loo AHB, Samsuri H, Seah EEL, Turner IM, Yong JWH. A botanical survey of Sungei Buloh Nature Park, Singapore. Gard Bull Sing 1997;49;15-35.

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