The Mercurialineae and Adenoclineae of South Africa. 
BY 
D. PRAIN, C.I.E., F.R.S. 
Director of the Royal Gardens , Rezv. 
Introductory. 
I N a former paper (Ann. Bot., xxv. 575—638) the writer, in reviewing the 
Euphorbiaceous genera Erythrococca , Benth., and Micrococca , Benth., 
discussed a suggestion made by Baillon in 1 86a (Adansonia, iii. 167-76) 
that these two genera, with Claoxylon . A. Juss., Adenocline , Turcz., and 
Seidelia, Baill., are referable to Merciirictlis. There is little to add to the 
reasons given in 1911 for adopting another view. But as a revision of 
Erythrococca and Micrococca was called for then 1 when preparing the 
‘Flora of Tropical Africa’, so now, in preparing the ‘Flora Capensis’, 
a similar revision is required of Seidelia and Adenocline, and of certain 
South African species included in 1862 by Baillon in Mercurialis , but 
transferred in 1866 to two new genera, Leidesia and Par adenocline, proposed 
(DC. Prodr., xv. 2, 792 ; 1141) by Muller. 
History of Mercurialis procumbens. 
When Linnaeus dealt with Mercnrialis in the first edition of the 
‘Species Plantarum ’ in 1753 on b / his fourth species, M. procumbens , Linn. 
(Sp. PL, ed. i, 1036), was African. The earliest reference to this species is 
over half a century older ; it was one of the plants obtained in South 
1 Since that revision appeared one doubtful point has been cleared up. It was stated (Ann. 
Bot., xxv. 605) that Claoxylon sphaerocarpum, O. Kuntze (Rev. Gen. PI., iii. 2, 248), almost 
certainly belongs to some other genus. Through the kindness of Dr. N. L. Britton, Director- in-Chief, 
New York Botanic Garden, we have seen the original specimen; it is really Croton sylvaticus, 
Hochst. Since 1911 it has been necessary to describe two new species of Micrococca : M. scariosa, 
Prain (Kew Bulletin, 1912, 192), an East African species representing a new section ; and M. land - 
folia , Prain (Kew Bulletin, 1912, 282), a Madagascar plant most nearly allied to the South-east 
African M. capensis. To the synonyms of the genus Micrococca must be added Mercurialis § Tris- 
megista, Endl. (Gen. PI., mi [1840]) ; to those of the species M. Mercurialis , Benth., should be 
added Ricinokarpos indica glabra Mercurialis folio , Burm. (Thes. Zeyl., 205 [1737]). From a recent 
contribution to African botanical literature by Dr. Mildbraed (Wiss. Ergebn. Deutsch. Zentr.-Afr. 
Exped., 1907-8, ii. 452 [1913]) we learn that Dr. Pax now treats Claoxylon § Discoclaoxylon, Mull, 
arg., as a distinct genus Discoclaoxylon , Pax, and that he also treats Claoxylon § Athroandra , Mull, 
arg., as a distinct genus Athroandra. Both decisions, as has been explained (Ann. Bot., xxv. 596, 605), 
though permissible, are really unnecessary ; the latter, however, had been, with a defect of ortho- 
graphy, anticipated by Pierre (FI. Trop. Afr., vi. 1, 868). The generic name used by Pierre and 
by Pax is not permissible; if the group Athroandra be treated as a genus the name to be used is 
Chloropatane , Engl. 
[Annals of Botany, Vol. XXVII. No. CVII. July, 1913.] 
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