Raoulia tenuicaulis, known as the tutahuna in Te reo or mat daisy, is a species of flowering plant, endemic to New Zealand. It is the most widespread "Raoulia", and grows mainly in riverbeds. Description. A small shrub that grows on mats in river-beds. It forms mats up to 1m in size. Distribution and habitat. "Raoulia tenuicaulis" is known from across New Zealand, on both the North and South Island. It thrives in stony riverbeds in both montane and lowland regions. It is not considered threatened in its range. Ecology. "Raoulia tenuicaulis" is known to host "Cuscuta epythymum." Etymology. "tenuicaulis" means 'thin-stem' in Latin. The description also includes the note that it is thin-stemmed, so presumably this is why the name was chosen. Taxonomy. "Raoulia tenuicaulis" contains the following varieties: However, these are suspect, as the form can change with the growth pattern. The type series is uncertain, but a lectotype was gathered by William Colenso in 1863.