Revision of Genus Alstonia — MONACHINO 
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masi; K); Kit son 1019 (Ankobra; K). 
Ivory Coast — Chevalier 15194 (Bingeroville; 
G). 
Sierre Leone — Deighton 2993 (K); Thomas 
3934 (K). 
Gambia — Dawe 37 (K). 
Vernacular names. — Belgian Congo: 
Guga, Okuka; Mayombe: Songoti; Bunyoro: 
Mujiva. 
This species is in many respects more closely 
related to A. scholaris than it is to A. congensis. 
It might be conceived as an African variety of 
the former. The three form a closely knit unit. 
The greater part of the material distributed 
as A. congensis belongs to this species. 
4. Alstonia congensis Engl., Bot. Jahrb. 8: 
64. 1886. 
A. Gilletii De Wild., Miss. E. Laurent. 1: 537. 
1907. 
A. Gilletii var. Laurentii De Wild., Miss. E. 
Laurent. 1: 537. t. 162. 1907. 
A. congensis var. glabrata Hutch. & Dalz., FI. 
W. Trop. Africa 2: 42. 1931. 
Leaf blades closely resembling those of A. 
Boonei, more often acuminate at apex, sessiloid 
or sessile. Inflorescence sparsely puberulent or 
glabrous, generally more loosely and sparsely 
flowered than that of A. Boonei; calyx glabrous 
or sparsely pubescent; corolla tube 3.7-5. 7 mm. 
long, pubescent outside; corolla lobes 4.8-7. 3 
mm. long and 2. 5-4.7 mm. broad; anthers 1.2- 
1.6 mm. long; ovary glabrous or sparsely hairy. 
Follicles glabrous. 
Type. — "Congo; infra Ponta da Lenha. 
(4.9.74.).” Dr. Naumann, from Boma district. 
Illustrations. — Vermoesen, Man. Essences 
Forest. Congo Beige (1923) 16 (leafy br. and 
infL, fr., seeds) ; De Wildeman, Miss. E. Laurent. 
(1907) 2: t. 162 (as A. Gilletii var, Laurentii; 
leafy br.). 
Distribution. — West tropical Africa, the 
Congo Luanda, and Belgian Congo to Nigeria. 
Sometimes abundant; prefers humid habitat. 
Congo — Claes sens ( Br ) ; C orbisier-Baland 
1594 (Br, K); Dawe 305 (Angola; K); De- 
meuse 113 (Br); Germain 78 (Yandjia; Br); 
Ghesquiere 771 (Kasi; Br); Gilbert 54 m 
(Wolenge; Br); Gillardin 307 (Bakuba; Br, 
K); Gillet 3532 (Belg.; Br), 3751 (cotype A. 
Gilletii; Br); Laurent (3/1/04; type A. Gilletii 
var. Laurentii; Br); Lebrun 6691 (Mushie; 
Br); Leemans 57 6-580 (Eala; Br); Leontovitch 
28 ( Bud j ala; Br); Louis 12128 and 12134 
(Yangole; Br); Mortehan 848 (Dundusana; 
Br); Naumann (4/9/74; type coll. A. con- 
gensis; K); Paynaert 788 (cotype A. Gilletii; 
Br); Sapin (Kasai; Madibi; Br); Vanderyst 
(Balanda; Br). 
South Nigeria — Dalziel 1256 (type A. con- 
gensis var. glabrata; K ) . 
Vernacular names. — Same as for A. 
Boonei. 
Cotypes of A. Gilletii. — "Region de Kisantu, 
1904 (/. Gillet 3531) ; Sanda, 1904 (leg. 
Oddon, coll. J. Gillet 3751); Eala, decembre 
1906 (L. Pynaert 788)5 The type of A. Gil- 
letii var. Laurentii, collected by Laurent, "Bol- 
ombo, 3 janvier 1904,” is of sterile material. It 
was distinguished from the typical plant by the 
fact that the leaves were more numerous in each 
verticil (9, as against 4—7 in the typical 
species) . This character is too trivial for varietal 
segregation. 
Type of A. congensis var. glabrata (Kew BuL 
1937: 337). — "S. Nigeria: Lagos Town, Oct., 
Dalziel 1256.” A. Boonei (’ ( A. congensis ” of 
most authors and herbarium distribution) served 
as the basis for comparison with this plant. 
Hutchinson and Dalziel did not judge their 
plant as sufficiently different from A. Boonei 
for specific rank. 
The type is sterile and was collected from a 
young plant ("Strauch”). When flowering 
specimens of African Alstonia were subse- 
quently collected they were referred to this 
species because of the great vegetative simi- 
larity and because A. congensis was the only 
African species known at that time. This 
flowering material was accepted as character- 
izing A. congensis. Then A. Gilletii was dis- 
tinguished, chiefly on basis of its strikingly 
different floral features. As numerous collec- 
tions accumulated it became evident that two 
