HQl NGHI KHOA HQC T O A N Q U O C V £ SINH T H A I V A T A I N G U Y E N SINH VAT L A N THCT 5
DAC DIEM PHAN LOAI CHI RAU DU'A N u ' d c (Ludwigia L.) ' 6 VIET NAM
TRAN TH! HU^ONG, HA MINH TAM Truang Dgi hgc Suphgm Hd Ngi 2 D 6 TBI XUYEN Vien Sinh thdi vd Tdi nguyen sinh vgt.
Viin Hdn ldm Khoa hgc vd Cdng nghe Viit Nam Chi Rau dua nude {Ludwigia L.) thugc hg Rau dira (Onagraceae Juss.) cd 75 loai, phan bo chii yeu d viing nhi?t ddi va cgn nhiet ddi. CJ Vi?t Nam, chi nay hi?n biet cd 6 loai.
Cho dkn nay, da cd mgt so cdng trinh de cap dkn chi Rau dira nude d Vi^t Nam nhung vin chua diy dii vi that sy cd h? thong. Do dd, can cd mgt cdng trinh nghien cuu phan logi chuyen siu vi diy du dl thdng nhat, phyc VM tryc tilp vi?c bien sogn bd sach Thyc vat chi Viet Nam ve hg Rau dira (Onagraceae Juss.) va cho nhirng nghien ciru cd lien quan,
\. PHlTONG PHAP NGHIEN ClTU
L Doi tupng nghien cuu
Gdm tit ci cic taxon thugc chi Rau dira nude {Ludwigia L.) d Vi§t Nam, dya tren co sd la tu lieu va mau nghien cuu gdm 52 so hieu mau vdi 117 tieu bin thugc chi Rau dira nude {Ludwigia L.) cua Vi?t Nam, dugc luu giif tgi phdng tieu ban thyc vat Vign Sinh thai va Tai nguyen sinh vgt (HN) va cac miu vgt d trgng thii sdng trong qui trinh di6u tra thyc dja.
2. Phutmg phap nghien cuu
De thyc hien cac ngi dung nghien cuu, chung tdi da sir dyng phuong phap Hinh thii so sanh, theo Nguyin NghTa Thin (2007). Vi?c thu thap mlu vgt dugc tiln hanh tren phgm vi khip ci nude. Cdng tac dinh logi dugc tiln hanh tai Phdng Thuc vgt (Vi?n Sinh thii v i Tii nguyen sinh vgt) vi Phdng Thi nghiem Thuc vat hgc (Trudng Dai hgc Su phgm Ha Ngi 2).
n . KET QUA NGHIEN CtTU
1. Die diem nhan biet chi Rau dura nude {Ludwigia L.) d Viet Nam LUDWIGIA L.-RAU DU'A NU'CiC
L. 1753. Sp. PI. 1: 118; DeCandoIIe, 1828. Prodromus Systematis Naturalis. 3: 58; Benth.
& Hook. f. 1867. Gen. PI. 1: 788; Back. & Bakh. f. 1963. Fl. Jav. 1: 261; 1968. 3: 644; Vu Van Cuong & J. E. Vidal, 1973. Fl. Camb. Laos Vietn. 14: 18; Raven, 1977. FI. Males. 8 (2): 99;
Phamh. 2000. Illustr. FI. Vietn. 2: 68; Heywood, 1996. Flowering plants ofthe worid. 162;
Chen Jiarui, 2008. FL China. \3: 400.-JusslaeaL. 1753. Sp. PI. 1: 368; Benth. & Hook. f. 1867.
Gen. PI. 1: 788; Gagnep. 1921, FI. Gen. Indoch. 985; Back. & Bakh. f. 1963. FI. Jav. 1: 260.- Cubospermum Lour. 1790. Fl. Cochinch. llS.-Rau mirang.
Cd mdt hoac nhilu nim, gdc thudng hda gd, it khi la cd thuy sinh vdi phao xdp mau tring;
phan non khdng hogc cd ldng. La don, mgc cich, thudng hinh thudn, mep hau hit nguyen, gan hinh mang Idng chim. Hoa mgc don dgc d nach la, ludng tinh. Dai hg^i thanh ong dinh vdi biu, xe 4-5 (-6) thiiy, tdn tgi d qua. Canh hoa bing sd la dai, miu tring hoic vang, tiln khai van;
106
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hinh biu due den trung ngugc hogc hinh thia. Nhj ding sd hoac gi[) ddi sd thuy dai; bao phan dinh lung nhung ddi khi bd ngoai dinh gdc; hat phan don hoic bd bdn. Bg nhuy gdm 4 la noan hgp thanh biu ha 4 d, rat hiem khi nhieu hon; mdi d chua nhieu noan dinh tru giira; num nhuy dang cau. Qua nang, hinh dai dep hogc hinh try, thtrdng cd canh va long. Hat nhilu, hinh trdn hogc hinh trimg ngugc hay hinh bau dye, dinh true tilp vao vd qua hoac vao gia noan.
Typus: Ludwigia altemifolia L.
Co 75 Ioai, chii yeu d viing nhi^t ddi vican nhiet ddi tren the gidi. VietNam cd 6 loai.
Hinh 1. Sa do cdu lao hoa Hinh 2. Sa dd cdu tgo qud
2. Khda dinh loai cac loai thugc chi Rau dira nude {Ludwigia L.) d Viet Nam
IA. Cd thuy sinh ndi hoic bam vao biin, cd re phao trang, xdp 1. L. adscendens IB. Cd tren can, than dirng, phan gdc thudng hda gd.
2A. Nhi gip ddi sd thiiy dai.
3A. Dai cd3 gin, cinh hoa dai 6-17mm, chdp canh hoa lom, hat tron, 2 ranh
2. L. oclovalvis 3B. Dai khdng cd gin, canh hoa dai 2-3mm, chdp canh hoa trdn, hat hinh trung ngugc, nhieu ranh 3 L. hyssoplfoVia
28. Nhi bing sd thiiy dai.
4A. Hgt dai 0,8-1,4mm, dinh tryc tiep vao vdqua 4. L epilobioides 4B. Hat dii 0,3-0,6mm, dinh vao gia noan.
5A. Than non cd long, chdp canh hoa ldm, mdi d cd 2-nhieu hang hgt S.L. perennis 5B. Than khdng cd Idng, chdp canh hoa trdn, mdi d cd I hang hgt 6. L prostrata 3. Phan bo, sinh thai va gia tri tai nguyen chi Rau dira nuoc {Ludwigia L.) d Vict Nam
Phan bo vd sinh thdi: Cic dai dien thugc chi Rau dira nude {Ludwigia L.) a Viet Nam la nhimg cay hoang dgi phd bien, chiing thudng sdng d viing dat am, dam lay, rugng hoang, ven song sudi, ddp cao len den 1500m rai rac khap ca nude. Miia hoa qua rai rac quanh nim, nhung chii ylu thing 3-6.
Gid tri tdi nguyen: Chi Rau dira nude d Viet Nam chi cd 6 Ioai. Tuy cac loai deu la nhirng thyc vgt cd sinh khdi khdng ldn, nhung chimg cd vai trd quan trpng trong cac he sinh thai ndng 107
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nghiep. Trong dd, cd tdi 5 loai dugc ghi nhgn la lam thuoc dk chira nhilu b?nh khic nhau, 2 Ioai dugc dimg lam rau in cho con ngudi vi 5 loai lim thuc in cho gia siic.
IIL KET LUAN
Chi Rau dira nude {Ludwigia L.) d Viet Nam hien biet cd 6 loai, phan bo rai rac khap ca nude. Trong dd, cd tdi 5 loii dugc dung lim thudc, 2 loai lim rau an cho con ngudi va 5 loai lam thuc in cho gia sue. Chung tdi da tiln hanh xiy dyng ban md ta die dilm nhan biet chi, cung cip cac thdng tin tdm tit vl phan bo, sinh thai va gia trj tai nguyen, xay dung khda djnh loai cho 6 Ioai thudc chi Rau dira nude {Ludwigia L.) is Viet Nam.
Ldi cdm an: Chiing ldi xin trdn trgng cdm an sir gidp dd ve tu liiu nghien cuv vd dieu kiin nghien cim cua PGS TS. Nguyin Khde Khdi. PGS TS Vu Xudn Phuang. TS. Duang Due Huyen vd cdc ddng nghiip igi Phdng Thirc val hoc- Viin Sinh thdi vd Tai nguyen sinh vgt; cdc nha khoa hgc va cdc ddng nghiep Idm viic tgi cdc phdng lieu bdn th\rc vdt thugc Viin Sinh thdi vd Tdi nguyen sinh vgt. Tnrdng Dgi hgc Khoa hgc li.r nhien-Dgi hgc Qudc gia Hd Ngi, Vien Sinh hgc nhiet ddi thdnh phd Hd Chi Minh.
TAI LIEU THAM KHAO
Nguyen Tien Ban, 2003. Danh luc cac loii thyc vat Vi?t Nam. NXB. Nong nghiep, Ha Noi, tap 2- 933-934.
Backer C. A. & C. R. Bakhuizen, 1963. Flora of Java. The Netherlands, vol, 1:261.
Vo VanChi,2003.Tiidilnlhiic valthongdiing. NXB, KHKT, HiNpi, tap 1; 1609-1612.
Gagnepain F., 1921. Supplement a la Flore Generale de Tlndo-Chine, Paris,p.985-989.
5, Pham Hoing Hg, 2000. Cay co Vi?t Nam. NXB, Tre, tp. H6 Chi Minh, tgp 2: 67-69.
6. Raven, 1977. Flora Malesiana. The Netherlands, vol. 8 (2): 99-107.
' Tardieu-Blotm. L., 1975. Flore du Cambodge, du Laos et du Vietnam. Paris, tome 14: 18- 31.
8. Nguyen NghTa Thin, 2007. Cic phuong phip nghien ciiu thyc vgt. NXB. Dai hpc Quoc gia Hi Npi, 171 trang.
TAXONOMICAL CHARACTERISTICS OF Ludwigia L. IN VIETNAM
TRAN THI HUONG, HA MINH TAM, DO THI XUYEN
SUMMARY
Genus Ludwigia L. (Onagraceae Juss,) has 75 species, widespread distributed in tropical and subtropical regions of the world, on different kinds of soil. In Vietnam, the Ludwigia has 6 species. In this article, we described characteristics of genus Ludwigia in Vietnam, added information of distnbution.
habitat, ecology and use of Uiis genus in Vietnam, and established diagnostic key to the 6 spedes of Ludwigia in flora of Vietnam.