Weinmannia racemosa. Kāmahi.
Māori names
Common names
black birch (see note)
Dyes
Used for tanning. Exported (Colenso 1868a ; Buchanan 1869).
Kāmahi, kāmai are also names of dyes obtained by boiling and soaking the bark of the kāmahi. Produced reddish, permanent dye. "It was regarded as having a preservative effect and fishing lines were sometimes soaked in it to preserve them, and mats were stained with it." (Beattie 1994)
Domestic
Used like mahogany (Colenso 1868a). (N.B. Details on post-European timber uses generally not part of this database).
Among museum artefacts he tested Wallace 1989 found a fernroot beater and a teka made of kāmahi.
Among Tūhoe, tawhero "generally used for the larger, heavier, and unadorned handles of the adzes used as tools for rough work, as dubbing down baulks of timber" (Best 1912).
Medicinal
Inner bark - purgative decoction (White 1887)
"Bark from west side of the tree, from which the outer rind has been scraped off, is steeped in hot water and the decoction taken internally as an aperient in cases of abdominal and thoracic pain" (Brett's Guide 1883; Goldie 1904).
Bark infused in boiling water - a good tonic ( O'Carroll 1884).
Inner bark is a laxative (Bell 1890)
Related pharmacology, see Brooker, Cambie and Cooper, 1987.
Chemistry
Bark contains tannins and catechin (Aston 1923a).
Tannin properties dealt with by various authors (see Aston 1918b, 120).
Notes
" ... in others [parts of the colony], the name [black birch] is applied to the tawhero (Weinmannia racemosa)." (Conservator of State Forests 1877)