Ignored or disdained as a “weed tree” for many years by forest industrialists, Pacific or western yew received an unsustainable amount of interest in the last few decades of the 20th century due to the presence of paclitaxel in its bark.
Paclitaxel is used in the treatment of a range of cancers, including “ovarian cancer, breast cancer, lung cancer, Kaposi sarcoma, cervical cancer, and pancreatic cancer”. Prior to the discoveries of total synthesis of the compound in the early 1990s, paclitaxel had to be extracted from Pacific yew bark. This resulted in the death of the tree. Between exploitation for the chemical compound and forestry practices, the global population of Taxus brevifolia is estimated to have declined between 10 and 30% within its last three generations (a generation being roughly 30 years); this resulted in a IUCN Red List status of Near Threatened.
Taxus brevifolia has a range that spans both the coastal and inland temperate rainforests of western North America. At lower and wetter elevations, it is a small understory tree in forests otherwise dominated by larger conifers. Occasionally, in drier conditions, it will form a sprawling shrub. See the Gymnosperm Database for an excellent write-up and additional photographs: Taxus brevifolia.
Today’s photographs highlight two features of Pacific yew that are uncommon in conifers. The first is the fleshy red cone or aril. Encompassing a single seed, the aril is derived from a single modified seed scale which does not lignify (become woody). It is notably mucilaginous when crushed between one’s fingers. The second photograph is my attempt at showing how even the trunks of established trees can layer; when trunks or branches of Taxus brevifolia touch the ground (or in this case the tree trunk of a larger fallen tree), adventitious roots can be formed in order to increase nutrient and water uptake.