The concept of the “largest plant” is not straightforward, as “largest” can be defined in multiple ways. Plants exhibit gigantism across various metrics, including total mass, the area they cover, and their vertical height. Each of these definitions highlights different biological strategies for growth and survival, leading to diverse organisms holding distinct records. Understanding these various measures provides insight into the remarkable scale and adaptability of plant life on Earth.
Largest by Mass and Volume
The largest plant by sheer mass or volume refers to the total living material or woody tissue within a single organism. This often means the trunk and branch volume of a tree, excluding the root system for practical measurement. The current record holder is the giant sequoia ( Sequoiadendron giganteum ).
The most well-known example is the General Sherman Tree, located in Sequoia National Park, California. This monumental tree stands approximately 83.8 meters (275 feet) tall and boasts an estimated bole volume of 1,487 cubic meters (52,513 cubic feet). Its dry mass is estimated at 582 metric tons (642 US tons), with bark contributing 48 metric tons (53 US tons). The General Sherman Tree is estimated to be between 2,000 and 2,700 years old, dating back to the early Roman Empire.
Measuring the volume of such immense trees involves complex methods. This is achieved by subdividing the tree into smaller sections, measuring their dimensions, and totaling the volumes. Methods include tree climbers taking direct measurements or using ground-based optical and electronic surveying equipment. These measurements focus on trunk volume, not including branches, foliage, or roots, as these are challenging to quantify accurately.
Largest by Area
The largest plant by area refers to a single genetic individual that has spread extensively through vegetative reproduction, forming a clonal colony. What appears as many individual plants above ground is interconnected by a vast, shared underground root system, making them genetically identical clones of an original parent.
The most prominent example is Pando, a quaking aspen ( Populus tremuloides ) clone in the Fishlake National Forest in Utah. Pando spans approximately 43 hectares (106 acres) and comprises an estimated 47,000 genetically identical stems. Its estimated total weight is 6,000 metric tons (6,600 US tons), making it the heaviest known living organism. While individual aspen stems live for about 100 to 130 years, Pando’s root system is estimated to be several thousand years old, dating back to the last ice age.
This spread occurs through suckering, where the root system sends up new shoots that develop into what appear to be individual trees. Clonal reproduction via underground stolons or rhizomes is common in species like aspens, allowing them to colonize vast landscapes. Another notable example is the seagrass Posidonia australis in Shark Bay, Western Australia, covering approximately 200 square kilometers (77 square miles).
Largest by Height
The largest plant by height is the tallest living individual, measured from its base to its highest point. The current record holder for this vertical dimension is the Coast Redwood ( Sequoia sempervirens ). These trees are native to a narrow band along the Pacific Coast of North America, from central California to southern Oregon.
The tallest known living tree is Hyperion, a Coast Redwood in Redwood National Park, California. Discovered in 2006, Hyperion measured 116.07 meters (380.8 feet) tall by 2019. It is estimated to be between 600 and 800 years old. Its exact location is kept confidential to protect the tree and its surrounding habitat from visitor impact.
These towering trees thrive in specific environmental conditions, including abundant winter rain, moderate year-round temperatures, and consistent coastal fog. Fog plays a significant role in their survival, protecting them from summer drought by condensing on their crowns and dripping to water their roots. The thick, reddish bark of Coast Redwoods provides resistance to insects, fungi, and fire, contributing to their longevity and immense heights. Measuring such tall trees presents challenges due to visibility, distance for accurate measurement, and instrument limitations. Experts use laser rangefinders or direct tape-drop measurements by climbers to ensure accuracy.