Ulva and water lily are two different plants.

One, the appearance of different

1, Ulva

perennial aquatic herb, flowers bisexual, fibrous root system, mainly distributed in the 10-15cm soil layer; rhizome with leaves and stolons, the latter in the node of the root, and the birth of leafy branches and other stolons. Leaves elliptic-rectangular, 3.5-6 cm long, 5-10 cm wide, blue-green below, glabrous on both sides, crinkled from the veins; petiole 25-40 cm long, and pedicels pilose.

Flowers 1-2 cm in diam., dark purple; pedicel 6-10 cm long; sepals and petals striped, 1-1.5 cm long, apex rounded; anthers striped, ca. 4 mm long; carpels striped, puberulent. Nut rectangular-orbicular-ovate, with 3 or more mature carpels; seeds 1-2, ovate. Fl. June, fr. Oct-Nov.

2, water lily

Perennial aquatic herb; rhizome fertile. Petiole cylindrical, slender. Leaves elliptic, floating in the water, entire, leaf base cordate, leaf surface dense green, dark purple on the back. Leaves dimorphic: floating leaves rounded or ovate, base with curved notch, cordate or arrow-shaped, often without emergent leaves; submerged leaves thinly membranous, fragile.

Flowers solitary, floating or emergent; calyx four, green; petals usually eight. Fruit obovate, about 3 centimeters long. Flowers large, beautiful, floating on or above the water, blooming during the day and closing at night; sepals nearly free; petals white, blue, yellow, or pink, in multiple whorls, sometimes the inner whorl tapering to stamens; connective with or without appendages.

Carpels annular, adnate and half-submerged in fleshy cupular receptacle, and partially fused with it in the lower part, extending into style in the upper part, the stigma forming a concave stigmatic disk, the ovules anatropous, pendent on the inner wall of the ovary. Berry spongy, irregularly dehiscent, ripening under water; seed hard, gelatinous, with fleshy cupular aril, embryo small, with little endosperm and abundant exosperm.

Two, different growth habits

1, Ulva

Born in ponds and lakes. Young stems and leaves for vegetables. China's south of the Yellow River, western Hubei Lichuan and Chongqing Shizhu County, all the swamp ponds have grown in Jiangsu's Taihu Lake (or "Taihu Lake, one of the Eight Immortals"), Gao Bao Lake in the north of Jiangsu Province, especially Lichuan City, Hubei Province, Fubao Mountain Ulva exported to South Korea, Japan and other countries.

Hangzhou's West Lake and Leibo County's Lake Ma, Lichuan City, Hubei Province, and Chongqing Shizhu County, Huangshui Town and other places of production of Brasenia schreberi is known around the world. Pick its young leaves have not yet revealed the surface of the water to eat, is a local dish, the ancient so-called "Brasenia schreberi flavor" in the "Brasenia schreberi," refers to this dish, but also for medicinal purposes.

The growth temperature of Brasenia schreberi is 20～30℃, the water quality is clean, the soil is fertile, the water depth is 20～60 cm in the water grows well, the water surface temperature reaches 40℃ when the growth is slow, the temperature is lower than 15℃ when the growth is gradually stopped, the assimilation product to the stem in the storage and transportation, the dormant buds are formed. In case of frost, the leaves and part of the stem in the water withered and died, and overwintered with underground stems and stems left in the water.

2, water lily

Water lily like sunlight, well-ventilated, so the daytime blooming tropical and cold-hardy water lilies in the evening flowers will be closed, and in the morning will open. In ponds with shade along the shore, although it can bloom, but the growth is weak. The soil requirements are not strict, pH 6 ~ 8, can grow normally, the optimal water depth of 25 ~ 30cm, the deepest shall not exceed 80cm.

Prefer organic matter-rich loamy soil. March ~ April sprouting long leaves, May ~ August successive flowering, each flower bloom 2 ~ 5 days. The flowers are followed by fruits, and the stems and leaves wither in October and November. In the following spring, it re-sprouts again.

In the Yangtze River basin in late March to early April sprouting, late April or early May pregnant buds, June to August for the full bloom period, October to November for the yellow leaf period, after November into the dormant period. Born in ponds and lakes, some parks are often cultivated in the pool.

Three, the geographical distribution of different

1, Ulva

Ulva was widely distributed in the northern hemisphere in many areas, is now mainly distributed in China, Japan, India, Australia, North America, Canada, etc., the eastern part of Oceania and the western part of Africa are distributed. In China, it is mainly distributed in Yunnan, Sichuan, Hunan, Hubei, Jiangxi, Zhejiang and Jiangsu provinces, and it is widely distributed in the area south of 30°N latitude.

2, water lily

Water lily most of the native North Africa and Southeast subtropical regions, a few produced in South Africa, Europe and Asia's temperate and frigid regions, Japan, North Korea, India, the former Soviet Union, Siberia and Europe. The United States also have. Domestic distribution of Yunnan to the northeast, west to Xinjiang. Provinces and districts are cultivated.

Baidu Encyclopedia - Water Lily

Baidu Encyclopedia - Brasenia schreberi