BAMBOO, a grass (草), is the fastest growing, fastest rising plant on Earth. Two key attributes of bamboo are its flexible stiffness when cut and dried that returns to a stiff shape after bending, but a second trait little known in the West is that bamboo when green and growing is extremely flexible. Outer plants of a grove can bend completely over with the head touching the roots, and then spring up again repeatedly with a blowing breeze. As a growing plant after becoming mature, BAMBOO does tend to grow HEAD DOWN…at times BENDING COMPLETELY OVER as heavy tops full of leaves on mature plants bow over toward the ground, appearing to continually kowtow and bob. Bamboo species grow to lengths of 30 meters, about 100 feet or so. The root system of bamboo is also hooked together laterally fairly well with「prone streams」(of roots) just under the surface, as anyone who has ever tried to dig it out can attest.
Formerly, glyphs meaning BAMBOO included elements of「lordosis position」with「soil compaction, plugging」(筀),「flow of fluids with LAVA mound, mountain-like shape」(汕), and「kowtow bowing」with「craft in flesh seam, full frontal nudity or kinky and bent over」(筇, 笻, 篔, 簹). This glyph contains「head of rod down, head of male with blasted discharge」that describes the action of drooping and bending down after a climactic event and the subsequent draining of blood from the corpora cavernosa and corpus spongiosum. 竹 describes the opposite condition of 立. Continuing that analogy, bamboo as a「shoot」also emerges from a surrounding sheath as it grows longer.
「Head down, prone with a stream or a vigorous male」describes the LORDOSIS position of kneeling on all fours with one's head down.
As an element, this sometimes depicts bamboo slats that were joined into scrolls and written upon to keep permanent records in ancient China, and the bamboo calligraphy brushes used to write glyphs. The process of writing is described as「head down, head of male」(women were not taught or permitted to read and write, generally) or「head down, with a prone stream」of written characters on the page.
「Head down prone streaming male's head」: bamboo strips were cut when green and pliable and woven into baskets. One of these uses was as a protective supporter, exactly as a codpiece was used in Europe and an athletic supporter with cup is used by male contact sport athletes today. The basket not only provided some protection against painful and unwanted contact of sensitive infected areas, but enabled a poultice filled with mashed grains and herbal treatments to maintain constant contact with the infected areas, provide deodorant functions, and hold absorbent batting.

External source definitions …excluding politically incorrect concepts and other meanings deemed offensive today; may include extended definitions, euphemisms, and mnemonics)
Chinese: bamboo
Japanese EDRDG: bamboo
Unihan extended: bamboo; flute

Used within names (nanori)
たか