Locust leaf ping
Chinese other names: Centipede Ping, Bian Ji Ping, Water Hundred Feet, Locust Scoop, Water Tongue Grass, Big Duckweed, Bao Tian Ma, Ma Ping, Big Fish Ping, Centipede Drift, Grass Shoe Apple
Latin name: Salvinia natans (L.) All.
English name: Duck-weed
Biological characteristics: annual floating aquatic weed; slender stem, transverse, rootless, densely covered with brown nodular short hairs. Leaves 3 rounds, two pieces of floating water, a fine crack like silk, the formation of false roots in the water, densely knotted coarse hairs, water surface leaves are closely arranged on both sides of the stem, shaped like locust leaves, leaves oblong or oval, 8-13 cm long, 5-8 mm wide, the apex round blunt head, the base round or slightly yellow heart-shaped, the midrib is obvious, the lateral veins are about 20 pairs, there are 5-9 protrusions between the veins, a cluster of coarse short hairs on the protrusions, full margin, above green, below gray-brown, with knotted coarse short hairs, the petiole is about 2 mm long. 4-8 spore fruits are concentrated at the base of the underwater leaf. There are large and small sizes, the macrospore fruit is small, the few large sporangia with short stalks each contain 1 macrospore 1 3 microspore fruit is slightly larger, and most of the small sporangia with long stalks have 64 small spores each. Spore fruit is produced in late autumn and early winter, and the sporangia are dispersed in the spring of the following year, and the spores germinate in the sac. Propagation by spores, or vegetative propagation by plant breakage.
Habitat, hazard and distribution: it grows in ponds, paddy fields, still-water streams, northeast China, Qinling and other areas; weeds are common in rice fields, with small occurrence and little harm. It is distributed in the south of the Yangtze River and north China in China.
Prevention and control strategies: see "Ping" under the same article.
duckweed
Other names: Qingping
Latin name: Lemna minor L.
English name: Common Duckweed
Biological characteristics: annual phytoplankton. The leaf body is symmetrical, inverted ovate oval or nearly circular, 2–5 mm long and 2–3 mm wide, with inconspicuous 3 veins, green on both sides; the root sheath has no appendages, and the root tip is blunt. The fruit is nearly gyro-shaped; the seeds have deep longitudinal veins. The flowering period is from June to July, and it generally does not flower very often, and it is asexual propagation with buds.
Habitat, hazard and distribution: it grows in paddy fields, pond swamps or other still waters, often mixed with ziping, forming a floating community with dense water surface, which is a common weed in rice fields and aquatic vegetable fields, and the harm is general. It is found all over the country.
Prevention and control strategy: roughly the same as "Ping". Options include pyrazulfuron, benzylsulfuron, sodium pentachlorophenol and copper sulfate are highly sensitive to duckweed. In addition, ducking in rice paddies is an application of a biological control method that has not faded for thousands of years.
Zi Ping
Chinese other names: purple-backed duckweed, water duckweed
Latin name: Spirodela polyrhiza (L.) Schleid. = Lemna polyrhiza L.
English name: Common Ducksmeat
Biological characteristics: annual aquatic herb, floating water. The leafy body is inverted and ovate, 4-11 mm long solitary or 2-5 clusters, flattened, dark green, with 5-11 palmate veins, and 5-11 fine roots below. Flower unisexual, female flower 1 and male flower 2 are born together in the bag-shaped Buds; male flowers, anthers 2 chambers; female flower sub-room l room, with 2 upright ovules. The fruit is round and winged. Flowering occurs from June to July, and flowers rarely bloom. Propagate as buds.
Habitat, hazard and distribution: it grows in paddy fields, ponds, shallow ponds, swamps and ditches, often mixed with duckweed, and is a common weed in rice fields and aquatic vegetable fields, and the harm is not great. It is found in all provinces and autonomous regions of the country.
Prevention and control strategy: synonymous with "duckweed" upstairs.
Note: This species is distinguished from duckweed by the leaf back. Duckweed is green on both sides, and the back of the duckweed is brownish green to purple-brown.
Corn grass
Chinese other names: April Fly, Melon Grass, Melon Sore Grass, Universal Detoxification Grass, Dragon Grass
Latin name: Mollugo stricta L. = Mollugo pentaphylla auct. non L.
English name: Strict Carpetweed
Biological characteristics: Annual herb, 10-30 cm tall, whole hairless. The stems are spread out and multi-branched. Basal leaves are rosette-shaped, inverted lanceolate; stem leaves are often 3-5 or alternate, lanceolate or strip lanceolate, 1.5–3 cm long and 3–7 mm wide; petioles are short or nearly sessile. Heterophyllum polygonal inflorescence apical or axillary; peduncle length 2–6 mm; sepals 5, celery, oval or nearly round; petalless; stamens 3; superior ovary, carpel 3. The capsules are ovoid or nearly spherical, about 2 mm long, with 3 lobes. The seeds are mostly kidney-shaped, yellow-brown, with most nodular protrusions. The seedling period is from April to May, and the flowering and fruit period is from July to (August) to September. Seeds propagate and bear large fruit.
Habitat, hazards and distribution: Prefers soils with moderate sunlight and humidity, but is also drought tolerant, especially in hilly and mountainous slopes of sandy arable land. It is an extremely common weed in the autumn drought crop fields of the provinces (regions) south of the Qinling Mountains and the HuaiHe River, which has certain harm to crops and is more harmful in local areas. Henan and Shandong are the northern boundaries of the distribution of this species.
Prevention and control strategies: There are many applicable agents, such as touch-killing glyphosate, paraquat, diphenyl ether herbicides, and systemic benzasone, which have good prevention effects. Generally not treated as a major weed.
Lotus grass
Chinese other names: shrimp pincer vegetable, full of stars, penghua chrysanthemum, knotweed flower, buffalo knee, crab foot grass, horseshoe vegetable, crab leg su, water golden bell, fly therapy grass, gold flower, safflower ink grass, white flower total grass mushroom, white chicken intestine, cabbage cabbage, white flower boy
Latin name: Alternanthera sessilis (L.) DC. = Alternanthera nodiflora R. Br.
English name: Sessile Alternanthera
Biological characteristics: annual herb. The stem is slender, rising or creeping, with two rows of longitudinal columns of white soft hairs, densely covered with soft hairs on the nodes. The leaves are opposite, oval lanceolate or lanceolate, 2–8 cm long, sharply pointed or blunt at the apex, tapering at the base into a short petiole, and wavy at the full margin or middle. Cephalic inflorescences are axillary, 0.5–1 cm long; each flower has bracts 5, lanceolate, dry membranous; dense flowers, indumentum 5, white, dry membranous; stamens are usually 3, sterile stamens triangular diamond-shaped, filament base together to form cups; pistils 1, heart skin 1, stigma-like. The fruit is inverted ovate, slightly flattened, with narrow wings on either side. The flowering period is from May to September, and the fruit period is from July to October. Vegetative propagation and seed propagation are carried out with creeping stems.
Habitat, hazards and distribution: It prefers to grow in wet land, and is a common weed in paddy fields, meadows, wet drylands, vegetable gardens, nurseries and orchards, and the harm is more severe. It is distributed in Anhui, Jiangsu, Zhejiang, Jiangxi, Hunan, Hubei, Sichuan, Yunnan, Guizhou, Fujian, Taiwan, Guangdong, Guangxi and other provinces and regions.
Control strategies: See upstairs under the synonym for "corn grass".
Remarks: This species and "hollow lotus grass" belong to the same genus of lotus grass in the family Amaranthaceae, and confusion often leads to between the two. The biggest difference is in the morphology of the inflorescences of the two: the inflorescence of the hollow lotus grass has a total peduncle, while the lotus grass has no total peduncle (see photo below). In addition, the hollow lotus grass on the stem of the two has no fine villi, and the lotus grass has two columns of fine villi that grow in the recessed grooves, which is an important difference in nutrients. In addition, hollow lotus grass is a perennial herb, while lotus grass is an annual herb except in South China.