t. Phytol. Res. 8 (2): 137-140,1995 WEEDS OF DELHI I - AND EUPHORBIACEAE

RAIM GUITA and ILG. MUKERII. Applied Mycotogy Laboratory, Departmeot of Botany, University of Delhi, Delhi- I I 0007, India eiant weeai *longing to families Cyperaceae and Euphorbiaceae werc collected fron differcnt pzirts of Delhi and identified. Sonr of these weeds occurred through out the year, while others for short periods. Keywords : Cyperaceae; Euphorbiaceae; Weeds.

will be collected with a view to develop Introduction ' mycoherbicides. In agricultural lands and forests, weeds compete with the beneficial and desired Resulb and Discussion quality of vegetation, reducing the yield and Three species of the genus were compete with crop products. Because weeds collected from different parts of Delhi, namely fornutrients, soil moisture and sunlight. Cyperus bulbosus, C. ticeps and C. competition, Depending upon the degree of compressus (Fig.l A-C). These species can yield 157o. v,eeds reduce the crop by l0 to be distinguished by their floral parts and compete with Crops diffei in their ability'to basal part of the stem. They occur through hosts to weeds. Weeds serve as alternate out the year. But their flowering and seed several crop insects, nematoues and formation occurs in the months of July, thrips and stem patlrogens. Insects like aphids, August and September respectively. These fliel survive on wild mustard, wild plants grow on the road side, garden and in pigweed There is no carrot,ragweed, etc. fields. detailed knowledge of Delhi weeds therefore is a 7-15 cm survey work was taken up. The main aim of Cyperus triceps small glabrous on a short this work was to assess weeds which are fast high; annual. Stem tufted smooth. spreading and harmful to the crops. thick root stock obtusely trigonous, kaves are long or usually shorter than stem, Materials and Methods 2-4 mm broad, linear, acute. Heads usually Serious attempts were made to collect all the 3-nate, rarely a few or upto 7, ovoid or Cyperaceaous and Euphorbacious weeds cylindric ovoid, light green sessile, middle growing in different parts of Delhi during one the largest,5-8 mm long, lateral spikelets different seasons. The time of their 2 mm long. Glumes 4 keeled, lower, appearance, reproduction, dissemination were lanceolate, acuminate, herbaceous, green, regularly noted thrciugh out the year (Table strongly nerved. Stamens 2, stigma bifid. l). Identification of tlnise weeds were made Achenes 1.3-1.5 mm long, ellipsoid, obtuse, using standard monographsr-3. Observations yellow bro1n, compressed. presence were also made with respect to of Cyperus bulbosas is a stoloniferous, any facultative and obligate parasites on these glabrous, erect perennial with numerous bulbs. weeds as has been reported by some eadie, Stolons very selender, with brown scales, workersaj. Diseases occurring on these weeds disappearing as soon as bulbs are formed, 137 t38 Gupta & Mukerji

Table 1. Weeds of Cyperaceae and Euphorbiaceae during the different months of the year. Jan. Feb. Mar. April May June July Aug. Sep. Oct. Nov. Dec Cyperaceae Cyperus bulbosus + + + + ++++F+S+S +D +S,D C. triceps + + + + ++++F+S+S +D +S,D C. comperessus + + + + ++++F+S+S +D +S,D Euphorbiaceae Acalypha + +V +B,F +S +S +F +S +S Euphorbia geniculata +D +D +V +F,S +S +F,S +F,S +F,S +s E. granulata +V +F,S E. hirta +F +F +S +V +F +S +S +V +V +F +S +S E. prostrata -+v +V +F,S +S +S +V +V +V Phyllanthus niruri ; +V +V +F.S +F.S +F.S +S +s V-Vegetative ; D-Dispersal of seed; F-Flowering; + for presence; S-Seed formation; - for absence. close to the end of stolons. Bulbs when ripe brown with rather concavd side, minutely ovoid, I cm long enclosed in a hard, black puncticulate some what ribbed at the angles. striate coat, which splits irregularly into . The most commonly ocurring lanceolate leaves. Leaves many, longer than disease on these weeds are leaf spots caused stem, 4 mm wide at the base, tapering whip by Cercospora caricis and Alternaria like. altemata, Tarspot caused by Phyllochora Infloresence subumbellate, tuwaiteii, Leaf rust by Puccinia intemrpted, rays 6-12 mm long. Bracts 3-6, romagnoliana, Stem .and root gall by the lowermuch exceeding the umbel, ending Synchytium cypeiit in whip like structure. Glumes 3 mm long, From the famiiy Euphorbiaceae the boat shaped, adpressed, multistriate, reddish most common weeds encountered were margins hyaline in lower part, obtuse or Euphorbia geniculata, E. hirta, E. prostrata, midrib green, produced into a short arista. E. granulata, Eclipta alba, Acalypha and Cyperus compressus is a glabrous Phyllanthus nisui @i9.2 A-D). These plants tufted annual. Roots with extensive growth, occured ttnough out the year. Euphorbia fibrous. Culms 5-35 cm tall, erect trigonous hirta is an erect, decumbent, annual herb. with rounded, smooth angles, striate. Leaves Stem simple or dichotomously branched, l-4 at base of culms, 1.5-3 cm wide as long rather pilose with yellow, spreading as culms, flat or conduplicate, margins rarely pubescence of minute, curved hairs. Leaves scabrellate, l-nerved, acuminate, sheaths very variable in size, opposite, obliquely purpulish brown. Bracs 3-5, unequal upto 10 lanceolate, oblong, acute. Seeds of E. hina cm long. Spikelets 3-10, subdigitate at the germinate immediately after their dispersal. end ofthe ray, linear, oblong, subcompressed Flowering starts in the month of January and with a median ridge on each side. Achenes seed formation takes place in march. In April, l-1.3 x 0.8-1 mm, obovoid, trigonus, dark germination of seeds take place then flowering J. Phytol. Res. 8 (2), 1995 139

Fig. I (A-C), Showing plants of Cyperus compressus, C. triceps and C. bulbosus. tak.'s place in May and again seed formation obovate, obtuse, rounded at apex, petioles takes place during June and July months. short, stipules subulate. Involucre axillary This process continues through out the year. short, subsessile, short, leaff like Its germination is very quick as well as it is branchlets. E. prostrata is an annual weed. very fast growing. Powdery mildew occurs Stem several spreading upto 2 dm long, also, appears on itduring the month of October branches altemate, usually slightly flattened and November. from above, glabrous with the line of puberulent hairs on the upper side. Leaves E. geniculata is an erect annual, 5- oblong, opposite, rounded at the apex. 9 dim high. Stem glabrous, terete, somewhat Infloresence short axillary, leafy raceme like sulcate when dry, internodes gradually branches with one. shortening towards apex, with a pair of branches coming f'rom the axil of opposite Acalyphaindicais an erect, annual leaves. Leaves elliptic, oblong, obovate, lower herb, 8-10 dm high. Stem simple with rarely alternate, upper forming an open rosette numerous branches, angular, sulcate when margins. Cymes densely corymbose, dry, shortly crisped, pubescent rarely woody involucres shortly pedicellate. Melampsora at the base. Leaves rhomboid ovate, acute, heliscopiae disease is found on this weed serrate, glabrous on both surfaces except at during the winter season6. Further, E the midrib and lateral nerves, lateral nerves granulata is a small, hispidly herb.Stems raised and pubescent on both surfaces. many annual, prostrate, spreading in all Inflorescence axillary, solitarv or geminate, directions. Leaves opposite, obliquely upto 8 cm long with 5-12 rather distantly 140 Gupta & Mukerji

Fig. 2 (A-D). Showing plants of Acalypha indica, Euphorbia hirta, E. geniculata and Phyllanthus niruri.

ranged females in the lower part, males very References few and terminal. l. Bhandari M M 19l.8, Flora of tlw lndian Desert, l-466 2. Collet H 1971, Flora simlenses l-656 Phyllanthus niruiis a small shrub, J. Maheshwari J K 1963, Flora of Delhi 1447 often herb like. Leaves alternate in two rows, botinical sessile or nearly so, glabrous entire. Flowers 4. Mulligan C A 1992, Common and names of weeds of Canada. Marketing and small clustered or solitary male and female Economics and Branch Agricultural Canada. obtuse. on the same plant. Sepals 6, oblong 1397lB-111 commonly occuning diseases on the Most Mukerji K G and Bhasin Jayanti 1986, Plant Phyllanthus are Leaf spot caused by disease of India 1468 by Cercospora phyllanthis, Fruit rot Rajee N Kumar, Gupta Rajni, ,Upadhyay R K Aspergillus niger, Cladospoium herbarum and Mukerji K G 1994, Eradication of a noxious and P enicillium islntdicum. kaf rust caused wend, Euphorbia geniculataby rust pathogen (In by Ravenelia emblicae. press).