JDH informs Asa Gray that he thinks Picrasma japonica is the same as P. ailanthoides. He is not convinced that Gray's Amaroria is a valid genus, it is close to Soulamea. JDH has seen Monroe. Asks Gray not to send things via bookseller as it is expensive, Trupena's charges are especially high. Mentions Gray's description of Holacantha, & correct use of the term hypogynous. Work on the Arctic flora has led JDH to consider the correct classification of North temperate flora, for example Alsineae; many of which could be referred to Stellarias, Holostea or Gramineae. Speculates that Greenland flora is unique & limited due to glacial factors. JDH can find no specimen of Dupontia cooleyi [at the RBG Kew herbarium]. He asks how Narthecium americanum differs from N. ossifragum. JDH has a newborn son [Brian Harvey Hodgson Hooker]. [George] Bentham is continuing the Hong Kong colonial flora, FLORA HONKONGENSIS, with support from the Treasury. JDH gives his opinion on [Richard] Owen's review of [Charles] Darwin's theory of evolution [ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL SELECTION]. Mentions reviews of his own essay [on plant distribution in the FLORA ANTARCTICA, supporting Darwin's theory]. Gray owes JDH for Horsfield's plants. JDH bought Booth's Bhutan plants at the [Thomas] Nuttall [estate] sale. [Letter incomplete, it bears no valediction or signature but is written in the hand of Sir Joseph Dalton Hooker].