Unless you are a plant ecologist, classifying the flora in New Zealand quickly becomes a guessing game as to what is native versus invasive. Unfortunately, so many of the plants and wildlife (most noticeably birds) are introduced that it practically becomes a 50/50 shot at the correct answer. However, others stick out like a sore thumb… in this case the russell Lupin (Fabaceae: Lupinus polyphyllus). Belonging to the same genus as my hometown Texas bluebonnet (L. texensis), they are characterized by palmately compound leaves that are alternate. Leaf matter resides at the base with near vertical stalks terminating in dense clusters of plump flowers. While the coloration of Texas bluebonnet does not vary much, russell lupin displays a wide variety of white, pink, purple, and red hues. Due to their striking colors, sheer abundance, and tall stature, russell lupin has become one of the most popular botanical attractions of New Zealand.
Near bodies of water at lower altitudes in NZ, the perennial lupins thrive extremely well. During the summer months especially, fields of russell lupin are impossible to pass by unnoticed. As invasive weeds, russell lupins dominate grasslands and wetlands, outcompeting native tussocks and marsh plants through sheer area coverage. Lupins are supposedly excellent dispersers as well, durable seeds transported through waterways and lakes. Much money and effort has been put into limiting the lupin distribution in NZ for over two decades, in hopes of preserving native plant biodiversity as well as nesting habitat for shorebirds. However, regulation is complicated. The flourishing sheep industry benefits from lupin as a nutritious feed which creates more productive pastureland. Lupin’s simultaneous agricultural value and detrimental ecosystem effects is a point of discord between local farmers and The Department of Conservation, creating the need for protocols that can effectively prevent the spread of lupin to areas that are currently untouched.
