Lotus is a perennial aquatic herb; its rhizome is horizontal, thick, with enlarged internodes, internally containing numerous longitudinal ventilation channels. The nodes are constricted, bearing black scale leaves above and beard-like adventitious roots below.
Leaves are roundish, shield-shaped, with a diameter of 25-90 centimeters, featuring a deep green surface covered in a waxy white powder. The back is gray-green, with entire margins slightly undulate, smooth on the upper surface, powdery, and the lower veins radiate from the center with 1-2 forked branches; petioles are robust, cylindrical, 1-2 meters long, hollow, and covered with small spines externally. Flower stalks are as long as or slightly longer than the petioles, also sparsely covered with small spines; petioles are cylindrical, densely covered with recurved spines.
The single flowers bloom at the top of the spike, towering above the water surface. Their diameter ranges from 10 to 20 centimeters, displaying beauty and fragrance. They come in various types such as single-petaled, double-petaled, triple-petaled, and even multi-layered. The colors vary from white, pink, deep red, pale purple, yellow, to bicolors. The lotus leaves are oblong-elliptical to inversely ovate, measuring 5 to 10 centimeters in length and 3 to 5 centimeters in width, gradually decreasing in size from the outside inward, sometimes transforming into stamens, with rounded or slightly pointed tips. The stamens are numerous. The pistil is separate and embedded within a conical, spongy receptacle, which has many scattered honeycomb-like holes on its surface. After fertilization, it gradually swells into a fruiting body called a lotus pod, with each hole containing a small nut (lotus seed). The flower stems are linear, with slender filaments attached below the receptacle. The style is extremely short, with the stigma located at the top. The receptacle (lotus chamber) has a diameter of 5 to 10 centimeters.
The nuts are elliptical or ovate, measuring 1.8-2.5 cm in length, with a leathery, hard shell that turns dark brown when ripe. The seeds (lotus seeds) are ovate or elliptical, 1.2-1.7 cm in length, with a red or white seed coat. The blooming period is from June to September, with flowers opening in the morning and closing at dusk each day. The fruiting period is from August to October. There are many cultivated varieties of lotus flowers, which can be divided into three major systems according to their uses: lotus root, seed, and flower lotus. [4]
Lotus is one of the ancient dicotyledonous plants, yet it also exhibits certain characteristics of monocotyledons. The bud of the lotus is enveloped by scales, similar to monocots. In terms of flower structure, the lotus has 3 to 4 whorls of sepals, with the outer ones resembling petals and the inner ones sepals, many stamens, a separate pistil, and pollen grains shaped like a boat with a single groove. The stem of the lotus shows distinct nodal segments, with underground stems covered in adventitious roots, features typical of monocots. The bud of the lotus is a mixed bud, with the lotus bud seen by people being the top bud of the rhizome and the axillary buds at each node. The roots are divided into two types: taproots and adventitious roots. The taproots formed from the seedling radicle of the seeds are not well-developed, while the adventitious roots are the ones that function. The stem of the lotus, or the rhizome, is the underground storage organ that stores nutrients and serves as a reproductive organ. The flower of the lotus is solitary, bisexual, consisting of six parts: sepals, petals, stamens, pistils, receptacle, and peduncle. There is a wide variety of species with rich colors. [5]
Lotus is a type of aquatic herb with its rhizome, or "lotus root," horizontally growing in the mud. The cross-section of the rhizome features numerous holes of varying sizes, which are air cavities formed to adapt to life in water. These air cavities can also be found in the petioles and stems. The stem is lined with small tubes for transporting water, their walls coated with a thick, mucilaginous lignocellulose. This material has some elasticity, allowing it to stretch and form many white, interconnected threads when broken. Older rhizomes have more threads than younger ones. The top bud of the rhizome is called "lotus cover," enclosed by scales. After germination, it produces a white, slender, underground stem known as "lotus stem." The stem is segmented, with adventitious roots forming around each node. Leaves and flowers emerge from the nodes. The new rhizome formed at the tip of the stem is called the "main rhizome," which can have 4-7 segments, each about 10-25 cm long and 6-12 cm in diameter. Branching off the main rhizome are the "child rhizomes," and from these, smaller, often single-node "grandchild rhizomes" grow. The size, shape, color, ripeness, depth of mud penetration, and quality and flavor of the rhizome vary by variety and are influenced by cultivation and conditions. [6]
The lotus leaf is large, with a diameter up to 70 centimeters, full and round, resembling a shield, featuring 14-21 radiating veins. The leaf surface is deep green, rough, and covered with short,钝spikes. Between the spikes, there's a layer of waxy white powder, causing raindrops to gather into rolling beads. The underside is a lighter green, smooth, hairless, with prominent veins, and in the center, a cylindrical leaf stalk sticks up, lifting the leaf above the water. The stalk has dense, downward-facing spikes, and the connection to the underground stem is white, while the parts above and below the water are green. The leaves are divided into three types: The initial leaves produced from the tip are small, with thin stems, floating on the surface, known as "coin leaves" or "lotus coins." The leaves that grow early from the lotus rhizome are slightly larger and also float, called "floating leaves." Later, the leaves that emerge from the rhizome above the water are called "upright leaves." Whether coin leaves, floating leaves, or upright leaves, they are all curled inward into ribbons before emerging. The upright leaves, depending on their growth stage, show a distinct ascending and descending staircase in size, height, and order. The upright leaves that emerge when new rhizomes are forming are larger than the previous ones and have shorter spikes, known as "rear leaves." In front of these, a smaller, shorter-stemmed leaf with a slightly reddish underside appears, called the "termination leaf." By identifying the termination leaf, one can locate the direction of the new rhizome in the mud.