REINWARDTIA Vol. 22. No. 1. pp: 27‒30 DOI: 10.55981/reinwardtia.2023.4423 27 A NEW RECORD OF EUPHORBIACEAE WEEDS FOR PENINSULAR MALAYSIA Received September 30, 2022; accepted May 9, 2023 RAFIDAH ABDUL RAHMAN Forest Research Institute Malaysia (FRIM), Kepong 52109, Selangor, Malaysia. Email: rafidahar@frim.gov.my https://orcid.org/0000-0003-1055-4894. NIK FAIZU NIK HASSAN Forest Research Institute Malaysia (FRIM), Kepong 52109, Selangor, Malaysia. Email: nikfaizu@frim.gov.my https://orcid.org/0000-0003-3377-3942. ABSTRACT RAFIDAH, A. R. & NIK FAIZU, N. H. 2023. A new record of Euphorbiaceae weeds for Peninsular Malaysia. Rein- wardtia 22(1): 27‒30. — Caperonia A.St.-Hil. is a new genus record for Peninsular Malaysia, with the species of Caperonia palustris (L.) A.St.-Hil. This paper will provide a description, distribution, habitat, and colour plates of the species. Key words: Flora, naturalized species, Peninsular Malaysia, taxonomy. ABSTRAK RAFIDAH, A. R. & NIK FAIZU, N. H. 2023. Rekaman baru gulma Euphorbiaceae untuk Semenanjung Malaysia. Reinwardtia 22(1): 27‒30. — Caperonia A.St.-Hil. merupakan rekaman marga baru di Semenanjung Malaysia, dengan jenis Caperonia palustris (L.) A.St.-Hil. Deskripsi, sebaran, habitat dan foto berwarna jenis ini disertakan. Kata kunci: Flor a, jenis ter natur alisasi, Semenanjung Malaysia, taksonomi. INTRODUCTION Weeds are often overlooked, ignored or mis- identified. As weeds become established and later reproduced, they are considered naturalized and become part of the flora. Some weeds are wide- spread and they grow aggressively and later be- come noxious weeds (Kiew, 2009). The majority of the most common and widespread weed species we know have become as a consequence of crop domestication, planting and cultivation (Dekker, 2016). Caperonia A.St.-Hil. (Euphorbiaceae) is a new genus record for Malaysia. Caperonia palustris (L.) A.St.-Hil., is native to Central and South America and was first reported as a new record in Java, Indonesia in 2019 (Anshori et al., 2020) where it grew as a weed along rice fields. Accord- ing to Anshori et al. (2020), the species may have been accidentally introduced into Java as a soil contaminant, but the time and vector of introduc- tion are uncertain. In Peninsular Malaysia, Caperonia palustris was encountered recently in rice fields in Perak and Selangor. At first, the spe- cies might be confused with Croton species, but after further examination and detailed study of the morphology, it was confirmed that the collected species is Caperonia palustris. The species was not recorded in Moody (1989), Turner (1997), or in the weed diversity of Sebarang Perak, Malaysia (Hakim et al., 2013). Hence, it is reported here as an additional new record for the Flora of Peninsu- lar Malaysia. Caperonia palustris has been described as an invasive alien species of rice fields in southern United States since 2007 where it is called as Texas weed (Miller et al., 2010; Godara et al., 2011) and is one of the most troublesome weeds in the Texas and Louisiana rice growing areas (Godara et al., 2012). The seeds are dispersed by water and both Koger et al. (2004) and Godara et al. (2012) showed that the seeds have a capability to survive under flooded conditions. Permanent flood establishment is an important cultural prac- tice for weed management in rice crops (Bouman et al., 2007). However, in Malaysia, the method of rice establishment changed to direct seeding in the 1980’s that provides aerobic conditions for weeds because they are not flooded during the initial growth stages of the crop (Karim et al., 2004). Flooding can affect both weed emergence and growth (Godara et al., 2011). Therefore, more adapted weeds can compete to grow for light, wa- ter and nutrients, which may cause losses in rice yields. The composition of weed species assem- blages in rice fields is rapidly changing due to fac- tors such as the increasing use of herbicides, changes in ploughing and fertilizer practices, crop- ping systems, and also environmental change by the creation of well-drained rice fields (Kosaka et al., 2006). http://dx.doi.org/10.14203/reinwardtia.v19i1.3850 10.55981/reinwardtia.v22i1.4423 https://orcid.org/0000-0003-1055-4894 https://orcid.org/0000-0003-3377-3942 https://dx.doi.org/10.55981/reinwardtia.v22i1.4423 https://orcid.org/0000-0003-1055-4894 https://orcid.org/0000-0003-3377-3942 REINWARDTIA 28 [VOL.22 Fig. 1. Caperonia palustris. A-B. Habit. C. Staminate flowers (lowest position of inflorescence), young buds (centre) and pistillate flowers (at the top). D. Top view of fruits (left) and pistillate flowers with white se- pals (right). E. Side view of fruits with the green persistent sepals. F. Persistent sepals of pistillate flowers (left and centre) and top view of fruit (right). Scale: 5 mm for C, D, E, F. 5 mm A B C D E F RAFIDAH & NIK FAIZU: A new record of Euphorbiacaea for Peninsular Malaysia 2023] 29 Euphorbiaceae is one of the largest, most com- plex and diverse families of angiosperms and are distributed mainly in the tropics, in various vegeta- tion types and habitats. The family comprises 225 genera and more than 6,300 species in the world (Challen, 2015). Euphorbiaceae consists of 81 ge- nera in the Flora Malesiana region (van Welzen, 2020). Now that Caperonia palustris is an addition to the Flora of Peninsular Malaysia, the descrip- tion, distribution and habitat are provided in detail here. MATERIALS AND METHODS Field survey was carried out in 2019 and 2021. Flowering and fruiting specimens were collected, examined and preserved using the standard herba- rium technique of Bridson & Foreman (1998) and deposited in the KEP Herbarium of Forest Re- search Institute Malaysia (FRIM). The morpholo- gical descriptions of this species was based on the examination of the fresh plants. TAXONOMIC TREATMENT CAPERONIA PALUSTRIS (L.) A.St.-Hil., Hist. Pl. Remarq. Bresil 3/4: 245. 1825; Anshori et al., J. Trop. Biol. Conserv. 17: 273. 2020. Basionym: Croton palustris L., Sp. Pl. 2: 1004. 1753 (‘palustre’). Herb to sub-shrub, woody at base, monoecious, erect, to 50–60 cm in height, with milky latex. Stems green, erect, cylindrical, ridged, hollow, with or without glandular hairs. Stipules triangular to lanceolate or subulate, 2–5 × ca. 1 mm, cadu- cous. Leaves simple, alternate; petioles green, slen- der, up to 15 mm long, glandular hairs present; lamina ovate, elliptic to oblong, 4–10 × 2–5 cm, base rounded to acute, margin serrate, with glands on leaf teeth, apex acute or acuminate; midrib prominent beneath, sparsely hairy, secondary vena- tion 8–12 pairs, pinnate, trinerved at base; tertiary venation conspicuous. Inflorescences racemose thyrse, axillary, up to 1 cm long; flowers unisexu- al, 1–4 proximal pistillate flowers, several distal staminate flowers; peduncles 2–4 cm long, hispid; bracteoles ovate, ca. 1 mm long. Staminate flo- wers: ca. 1.5 mm diameter; pedicel ca. 1 mm long; sepals green, 5, united at base, ovate-elliptic, ca. 1.5 × 0.4 mm; petals white, 5, free, obovate- oblong, ca. 3.5–2 × 1.5–2 mm long, clawed, disc absent; stamens 10, filament length unequal, whit- ish cream, united near the base into a column, free distally, filiform, anthers yellowish, oblong; pistil- lode present, minute, cylindrical. Pistillate flo- wers: 1.5–2 mm diameter, sub-sessile to sessile; sepals 5, united at base, ovate, unequal, in two rows, 3 inner larger, 3–5 × ca. 1 mm, 3 outer smaller, 1.5–2 × ca. 1 mm, persistent in fruit; pe- tals 5, white, free, oblong-lanceolate; staminodes and disc absent; ovary green, superior, trilocular with 1 ovule per locule, glandular hairs present, style short, stigma white, greenish at base, bifur- cate. Fruits subsessile, a trilocular capsule, deltoid at shape, 4–6 mm diameter, pilate glandular; per- sistent sepals 5–6, ovate to deltoid, ca. 5 × 3 mm. Seeds 3, brown, globose, ca. 2 mm diameter, ecarunculate. Distribution. Native to Centr al and South America. The species is present in tropical and subtropical America, and in the south of the USA (Texas, Arkansas, and Mississippi). It is common in tropical Africa, South Africa and Madagascar. In Malesia, it is reported as naturalized from Bo- gor (West Java) and Rembang (Central Java) (Anshori et al., 2020). In Peninsular Malaysia, it is recorded in Perak and Selangor. Habitat and ecology. The species can be found in ditches, rice fields along the canals and road- sides. In Bogor and Rembang, the species grows as a weed along rice fields and according to Anshori et al. (2020), the seeds are dispersed by water. A previous study showed that the seeds have a capability to survive under flooded condi- tions (Koger et al., 2004). Specimens examined. PENINSULAR MALAY- SIA: Perak, Hilir Perak, Chenderong Balai, 14 July 2019, Rafidah & Nik Faizu FRI 93110 (KEP); PENINSULAR MALAYSIA: Perak, Kg Changkat Budiman, 15 October 2021, Rafidah & Nik Faizu FRI 97360 (KEP); PENINSULAR MA- LAYSIA: Selangor, Sg. Besar, Pasar Jerami, 14 October 2021, Rafidah & Nik Faizu FRI 97361 (KEP). ACKNOWLEDGEMENTS The study was carried out as part of the Flora of Peninsular Malaysia Project funded by the Ministry of Natural Resources, Environment and Climate Change under the 12 th Malaysian Plans (SPPII No. P230851000210003). The au- thors would like to thank Dr. Ruth Kiew and Dr. Richard Chung for their constructive comments on this manuscript. REFERENCES ANSHORI, Z. A., IRSYAM, A. S. D., HARIRI, M. R. & RINA, R. I. 2020. The occurrence of Croton bonplandianus in Java and a new re- cord of Caperonia palustris for Malesia Re- gion. Journal of Tropical Biology and Conser- vation 17: 273–283. BOUMAN, B. A. M., LAMPAYAN, R. M. & TUONG, T. P. 2007. Water Management in REINWARDTIA 30 [VOL.22 Irrigated Rice: Coping with Water Scarcity. Los Banos (Philippines): International Rice Research Institute. Pp. 54–55. BRIDSON, D. & FORMAN, L. 1998. The Herba- rium Handbook. Kew Royal Botanic Gardens. United Kingdom. CHALLEN, G. 2015. Euphorbiaceae sensu stric- to. In: Utteridge, T., Bramley, G. (Eds.). The Kew Tropical Plant Families Identification Handbook 2nd Edition. Royal Botanic Gardens, Kew: Kew Publishing. DEKKER, J. 2016. Evolutionary Ecology of Weeds. 2 nd ed. Pp 552. GODARA, R. K., WILLIAMS, B. J. & WEB- STER, E. P. 2011. Texas weed (Caperonia pal- ustris) can survive and reproduce in 30-cm flood. W eed Technology 25: 667–673. GODARA, R. K., WILLIAMS, B. J. & GEAGHAN, J. P. 2012. Effect of shade on tex- asweed (Caperonia palustris) emergence, growth and reproduction. W eed Science 60(4): 593–599. HAKIM, M. A., JURAIMI, M. S., RAZI ISMAIL, M., HANIFI, M. M. & SELAMAT, A. 2013. A survey and weed diversity in coastal rice fields of Sebarang Perak in Peninsular Malaysia. The Journal of Animal and Plant Sciences 23(2): 534–42. KARIM, R. S. M., AZMI, M. & ISMAIL, S. 2004. Weed problems and their management in rice field of Malaysia: an overview. W eed Biology and Management 4: 177–186. KIEW, R. 2009. Additions to the weed flora of Peninsular Malaysia. Malayan Nature Journal 61(2): 133–142. KOGER, C. H., REDDY, K. N. & POSTON, D. H. 2004. Factors affecting seed germination, seedling emergence, and survival of texas weed (Caperonia palustris). Weed Science 52(6): 989–995. KOSAKA, Y., TAKEDA, S., SITHIRAJVONG- SA, S. & XAYDALA, K. 2006. Plant diversity in paddy fields in relation to agricultural prac- tices in Savannakhet Province, Laos. Economic Botany 60(1): 49–61. MILLER, J. H., CHAMBLISS, E. B. & LOE- WENSTEIN, N. J. 2010. A Field Guide for The Identification of Invasive Plants in Southern Forests. USDA For. Serv., Gen. Tech. Rep. SRS-119. Asheville, NC: Southern Research Station. MOODY, K. 1989. Weeds Reported in Rice in South and South East Asia. International Rice Research Institute. Philippines. Pp 552. TURNER, I. M. (1997 [‘1995’]). A catalogue of the vascular plants of Malaya. The Gardens’ Bulletin Singapore 47: 1–57. VAN WELZEN, P. C. 2020. Flora Malesiana Eu- phorbiaceae. Naturalis Biodiversity Center. http://www.nationaalherbarium.nl/euphorbs/. (Accessed on September 2022).