Chapter 7: The Phenological World of Guyu (Part One) — Duckweed Begins to Grow: The Image of Rootless Life and Warming Waters

Section 1: The Philosophical Significance of Phenology — Heaven and Earth Speaking Through Things

Guyu has three pentads (five-day periods): in the first, duckweed begins to grow; in the second, the cuckoo flaps its wings; in the third, the hoopoe descends upon the mulberry. Before delving into each pentad, we must first understand: why did the ancients place such weight upon phenology$6

Because, in the ancients' cosmology, Heaven does not speak, but rather "speaks" through phenology. The Master said: "What does Heaven ever say$7 The four seasons proceed on their course, and the hundred things are born—what does Heaven ever say$8" (Analects, "Yang Huo") Heaven never uses language; it expresses itself through the movement of the four seasons and the growth of the hundred things.

And phenology is precisely the concrete vocabulary of Heaven's "speech"—when duckweed grows, Heaven is saying "the water has warmed"; when the cuckoo calls, Heaven is saying "it is time to plow"; when the hoopoe alights on the mulberry, Heaven is saying "tend the silkworms." The ancients read phenology as one reads a book written by Heaven; through these subtle natural signals, they grasped the rhythm of Heaven and Earth's qi in motion, and accordingly arranged human production and life.

Guyu's three pentads happen to encompass three distinct domains: plants (duckweed), birdsong (the cuckoo), and sericulture (the hoopoe descending upon the mulberry). Through this cross-verification of phenology across three distinct domains, the ancients confirmed the true arrival of Guyu's qi, embodying a plain yet rigorous spirit of empirical verification.

Section 2: "Duckweed Begins to Grow" — How Does Duckweed Grow Without Roots$9

Guyu's first pentad is "duckweed begins to grow"—duckweed starts to sprout. The "Explanation of the Seasonal Instructions" chapter of the Lost Book of Zhou (Yi Zhoushu) records: "On the day of Guyu, duckweed begins to grow." This pentad, seemingly plain, in fact contains the ancients' profound apprehension of the relationship among "water," "warmth," and "life."

Duckweed is an exceedingly peculiar plant. It has no roots (or only fine, hair-like roots hanging in the water without taking hold in soil), floats upon the water's surface, and drifts with the waves. In the eyes of the ancients, this plant that "lives without roots" was a sign laden with meaning.

The ancients observed that duckweed sprouts and multiplies only once the water temperature has risen to a certain degree. Thus "duckweed begins to grow" is, at its core, a signal of "the water having warmed": when duckweed begins to spread across the water's surface, it shows that the water has already warmed, that the earth's qi has already risen, and that the chill has already been exhausted.

This responds precisely to "at Guyu, frost ceases"—the beginning growth of duckweed is precisely the phenological confirmation of "frost ceasing." The frost has ceased, the water has warmed, the duckweed has grown—these three are the manifestation, on different levels, of one and the same event: warmth overcoming cold.

Section 3: Life Without Roots — The Daoist Interest of Duckweed

"Duckweed begins to grow" is thought-provoking also because duckweed's characteristic of "living without roots" happens to touch upon the deepest mysteries of Daoist thought.

Ordinary grasses and trees all sink deep roots, firmly rooted, planted in the soil—this is the image of "a firm foundation" that Confucianism exalts ("the noble person attends to the root; once the root is established, the Way is born"). Duckweed, by contrast, has no root at all, does not take hold in the soil, but is born with the water and drifts with the waves. Its "life" does not depend on any fixed foundation, but depends on that "water" which upholds it and nourishes it. What a free, what a compliant posture toward life this is!

Master Zhuang (Zhuangzi), discussing life, places the greatest weight on "riding upon things to let the mind roam free" and "yielding and adapting along with things"—following the natural tendencies of the ten thousand things, letting the mind wander freely at ease. Duckweed, rootless and drifting, living with the water, is precisely a natural depiction of this posture of "riding upon" and "yielding and adapting": it clings to no single fixed foundation, does not resist the direction of the current; when the water warms, it grows; when the water flows, it follows; when the water dries up, it stops—all according with what is naturally so, entirely free of entanglement. The Most High says, "concentrating one's qi and attaining the utmost suppleness, can one become like an infant$10"—and also praises water's yielding suppleness and non-contention. Duckweed's suppleness, its compliance, its rootless ease, may well be regarded as a small embodiment, among plants, of the virtues of "suppleness" and "non-contention."

At a still deeper level, that duckweed can "live" despite having "no root" reveals a Daoist-style paradox: the foundation of life need not be a tangible "root," but might instead be that intangible, flowing "water" (the Dao) that upholds all things. Confucianism attends to the "root" (a tangible foundation), while Daoism reminds us: there is also a kind of "life" that depends on no tangible root at all, but rests directly within that ceaselessly flowing river of great transformation (water, the Dao). Guyu's first pentad, "duckweed begins to grow," quietly conceals, in utter silence, this very Daoist mystery.

Section 4: Duckweed and the Waters of Late Spring — Another Brushstroke of Heaven and Earth's Nurturing

The name Guyu places its emphasis on "rain," on "water." And the first pentad, "duckweed begins to grow," is likewise a matter of "life within water"—it forms a precise echo with "rain giving birth to the hundred grains," together writing out the theme of Guyu "nurturing life through water," differing only in that one occurs in the fields, the other in the water; one is prominent (the hundred grains), the other minute (duckweed).

The birth of the hundred grains is grand, bound up with the people's livelihood, and prominent; the growth of duckweed is minute, unrelated to livelihood, and unremarkable. Yet in the eyes of Heaven and Earth's nurturing, the two carry no hierarchy—both alike are life coaxed forth by a single warmth, a single expanse of water.

The humaneness of Heaven and Earth does not care only for the five grains that sustain the multitude, but cares equally for that duckweed drifting unnoticed upon the waves. A single Guyu brings forth both the hundred grains and the duckweed; it moistens both the prominent and the great and the humble and the small. This is precisely the other face of the Daodejing's statement, "Heaven and Earth are not humane; they treat the ten thousand things as straw dogs"—Heaven and Earth regard all things with perfect impartiality, neither favoring the hundred grains for their "usefulness" nor slighting the duckweed for its "uselessness."

Viewed in this light, "duckweed begins to grow"—this seemingly most unremarkable of pentads—in fact reminds us: the nurturing grace of Guyu extends universally to all things, without the slightest partiality. It bids us, even as we gaze upward in admiration at the abundance of "rain giving birth to the hundred grains," not to forget to look down as well, at that small duckweed quietly spreading across the water's surface, equally blessed by Heaven's grace.