84 
In 1888 Balfour dealt with the forms of Chrozophora trom 
Socotra (Trans. Roy. Soc. Edin. xxxi. p. 277) and enumerated 
three: —Chrozophora tinctoria, which is the condition during its 
first season of C. oblongifolia, A. Juss. (1826) and therefore is C. 
tinctoria, Schweinf. (1867) non A. Juss.; C. obliqua, which is 
normal C. oblongifolia, A. Juss. (1826) and therefore is C. 
obliqua, Miill.-arg. (1866) non A. Juss; lastly C. obliqua var. 
frutescens, Schweinf., which is based on specimens of C. oblongi- 
folia, A. Juss., from a plant older and more woody than usual. 
The species to which all three Socotra forms belong is rather 
variable in habit and appearance, a fact which is emphasised by 
the circumstance that in 1899 Schweinfurth (Bull. Herb. Boiss. 
vii. App. 2, p. 306) proposed the recognition of two more varieties, 
angustifolia and incisa, neither of which represents more than a 
condition of the type. 
In 1906 Broun enumerated four forms of Chrozophora from the 
Sudan (Cat. Sud. Fl. Pl. p. 72). These are C. obliqua from the 
Red Sea coast at Suakin which is C. obliqua, Mill.-arg. (1866) 
non A. Juss. and therefore is C. oblongifolia; C. Brocchiana from 
Dongola, Khartum, Sennar and Kordofan, supposed to be the 
‘species of Visiani as understood by Schweinfurth in 1862; C. 
senegalensis, based on the plant collected by Kotschy at Abu 
Gerad in Kordofan, an identification accepted from Miiller’s 
monograph of 1866; lastly C. plicata, the plant common “ on 
river-banks and in depressions on cotton-soil in most parts cf 
the Sudan,’’ which was the basis in 1790 of Croton plicatum, Vahl. 
In 1912 an official account of the tropical African forms was 
published by Kew (Fl. Trop. Afr. vi. 1). In this account four 
species were recognised, viz. :— 
1. Chrozophora plicata, A. Juss. (1826), delimited as it was 
in 1887 by Ascherson and Schweinfurth with the subdivision 
adopted by those authors into two varieties; one corresponding 
with Croton plicatum, Vahl (1790), the other corresponding with 
Croton obliquifolium, Vis. (1836) which is also Chrozophora 
obliquifolia, Baill. (1858) 
2. C. oblongifolia, A. Juss. (1826), under the name which it had 
borne without question until in 1866 Miiller inadvertently mis- 
identified the species with Croton obliquum, Vahl (1790). 
3. C. senegalensis, A. Juss. (1826), as the equivalentof Croton 
senegalense as cited by Lamarck in 1786 but as described by Vahl, 
through the agency of Geiseler, in 1807; with at the same time a 
variety lanigera, based upon the plant described as Croton sene- 
galense by Lamarck in 1786 but not cited by that author. 
4. C. Brocchiana, Vis. (1836), also with two varieties, one of 
which is that figr age Schweinfurth as var. Hartmanni in 1862, 
ich 
a form for w renberg had proposed the name Croton 
macrocalyz. 
History oF THE Inpran Species, 1869-1906. 
In 1869 Stewart alluded to the species of Chrozophora of the 
Panjab (Punjab Pl. p. 192). The influence of Miiller’s mono- _ 
graph on his treatment is evident. Stewart recognised only two 
