Thesium spicatum, commonly known as Spike Rootthug, is a herbaceous perennial plant belonging to the Santalaceae family. This species is recognized for its unique ecological role and distinctive morphology within its native range. Physically, Thesium spicatum typically presents as a low-growing plant, often reaching heights of 15 to 40 centimeters. Its growth habit is somewhat tufted, with erect to ascending stems arising from a woody rootstock. The leaves are linear to narrowly lanceolate, measuring approximately 2 to 5 centimeters in length and about 1 to 3 millimeters in width. They are sessile, meaning they lack a stalk, and are arranged alternately along the stems. The inflorescence is a spike, a characteristic feature that gives the plant its common name. These spikes are terminal and bear numerous small flowers. Each flower is typically bisexual, possessing a calyx but lacking petals. The calyx lobes are ovate to triangular and are persistent. The fruit is a small, indehiscent nut, often ovoid or globose, enclosed at the base by the persistent calyx. The seeds are small and smooth. The native distribution of Thesium spicatum is primarily within Australia, where it is found in various states including New South Wales, Queensland, South Australia, Victoria, and Western Australia. It thrives in a range of natural habitats, commonly occurring in woodlands, mallee scrub, and open grasslands. It often prefers well-drained soils and can be found in both sandy and loamy substrates. Cultivation requirements are not widely documented for ornamental purposes, but its native habitat suggests a preference for sunny to partly shaded conditions and drought tolerance once established. Ecologically, Thesium species are known to be hemiparasitic, meaning they derive some of their nutrients from a host plant through specialized root structures called haustoria. While specific host plant relationships for Thesium spicatum are not extensively detailed in general literature, this parasitic habit is a significant aspect of its biology, influencing the plant communities in which it grows. This adaptation allows it to survive in nutrient-poor environments. No significant ornamental, agricultural, medicinal, culinary, or economic importance has been widely established or scientifically documented for Thesium spicatum. An interesting characteristic of Thesium spicatum, shared with other members of its genus, is its hemiparasitic nature. This strategy allows it to supplement its nutrient intake by tapping into the root systems of neighboring plants, a remarkable adaptation that contributes to its survival in diverse and sometimes challenging ecological niches. The small, inconspicuous flowers are adapted for pollination by insects, though specific pollinators are not commonly detailed. The plant's ability to persist and reproduce in its native environments is a testament to its evolutionary adaptations.