182 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
DC., the type of the section, placed in the second group, hardly 
belongs there, as its inflorescence does not differ sensibly from that 
of J. marginata or the other species of the first group, while it 1s very 
distinct from the dense, short panicles of 7. aggregata or I, alba. 
Inga alba (Swartz) Willd. Sp. Pl. 4: 1013. 1806. 
Mimosa alba Swartz, Prodr. Veg. Ind. Occ. 85. 1788. 
Represented in the Gray Herbarium by several of Spruce’s collections (246, 
1076, 2289) identified by Bentham, and, in all the herbaria consulted by me, by 
Rusby & Squires 186, from Santa Catalina, Lower Orinoco, Venezuela. The 
specimens of this last number were distributed as Inga bourgont DC., but the 
flowers are much smaller than in that species, and the type of the inflorescence 
is very distinct. The large, flat glands and the strongly veined leaves also are 
characteristic of J. alba. The average dimensions of 5 flowers of Spruce 2289 
are 1.2 to 1.5 (1.3) mm. for the calyx and 3.4 to 3.8 (3.6) mm. for the corolla, 
as against 1 mm. and 3.1 mm., which are the dimensions given by Bentham. 
Inga aggregata Don, Hist. Dichl. Pl. 2: 391. 1832. 
Represented in our collections by Bang 1439, from between Guanai and 
Tipuani, Bolivia, also distributed under the name of J. bourgoni. Although I 
have not seen authenticated material of that species, the Bang specimens 
agree so well with the descriptions that I have no doubt about their identity. 
Inga marginata Willd. Sp. Pl. 4: 1015, 1806, excl. syn. 
This species is known to be exceedingly variable. In Central American spec- 
imens the flowers are usually pedicellate, though very shortly so; the calyx is 
always pubescent and the corolla broader and shorter than in the Brazilian 
tree. The form with marginate folial rachis is very seldom met with, and wings 
are present below both the basal and terminal pairs of leaflets. However, as 
all grades of transition are observed between the extreme forms, the separation 
of the species into subspecies is hardly practicable. 
Undescribed species of the marginata group probably will be found in Cen- 
tral America. Mr. William R. Maxon collected at Las Animas, near Maza- 
tenango, Guatemala, specimens whose leaves resemble those of the marginate 
form of Inga maryinata, or those of I. laurina, the leaflets being either 2 or 3- 
jugate. But the flowers are larger and the perfect pods are from 3 to 3.5 cm. 
broad and 12 em. long, with a strongly prominent margin. It does not seem 
desirable to describe this as a new species until further material is obtained. 
The same variability is noticed in I. laurina (Swartz) Willd., two or three 
apparently constant forms of which are found in Central America, The type is 
West Indian and the area of the species probably limited to the West Indies 
and the continental section between Panama and Mexico. The identification 
of the Bolivian plant distributed under this name by Dr. Buchtien (under 
no. 1767) is doubtful, but the specimens at hand are insufficient for the determi- 
nation of their real relationship. 
Section 4. PSEUDINGA. 
Series 1. GLABRIFLORAE, 
This group consists of a few Brazilian species, and has received 
no increase recently. Among its species /nga capitata Desv. is 
best known and has several varieties. Some specimens distributed 
under this name to American herbaria were found to belong to two 
distinct species of Pithecolobium. 
