Carbacanthographis sipmaniana is a species of corticolous (bark-dwelling) lichen in the family Graphidaceae. Found in Malaysia, it was formally described as a new species in 2022 by Shirley Cunha Feuerstein and Robert Lücking. The type specimen was collected from a montane rainforest in Kinabalu Park (Kota Belud, Sabah), at an elevation of . It is only known to occur at the type locality. The specific epithet sipmaniana honours lichenologist Harrie Sipman, "in recognition of his valuable contribution to tropical lichenology".
The lichen has a greyish brown to yellowish grey thallus lacking a cortex and a black prothallus. It has hyaline ascospores that measure 17âÂÂ20 by 6âÂÂ8 üm; these spores have between 5 and 7 transverse septa. Carbacanthographis pseudorustica contains norstictic acid and connorstictic acid, which are lichen products that can be detected using thin-layer chromatography.