May 35, 1914 
Eremocitrus 
87 
the stamens are normally four times as numerous as the petals, with the filaments 
free. The ovary is obovate, with a rather thick, subcylindric, caducous style, 4- 
or 5-celled, with two ovules in each cell; the disk is small. The fruits are 1% to 
2% by 1% to 1X cm.—smaller than those of any known species of Citrus—subglobose, 
oval or somewhat pyriform, with a thin, fleshy peel, like that of a lime, covered 
with oil glands. The pulp is vesicular, sour, and juicy. The pulp vesicles, which 
separate easily in the ripe fruit (fig. 2, A-D), are subglobose, and are borne on slender 
stalks. The seeds are small (5 to 6 by 3 to 4 by 2JA to 3 mm.), pointed ovate, yellow¬ 
ish gray with a hard testa, irregularly verrucose and furrowed in a longitudinal 
direction. (See fig. 2, E.) The cotyledons are plano-convex, remaining hypogeous 
in germination; the postcotyledonary leaves are slender cataphylls (fig. 3). 
This monotypic genus is based on Triphasia glauca Lindl., native to the drier parts 
of northeastern Australia. 
RELATIONSHIPS 
Eremocitrus is most nearly related to the three aberrant Australian 
species of Citrus, C. australis Planch., C . australasica F. Muell., and C. 
Garrowayi F. M. Bail., and 
agrees with them in having free 
stamens, subglobose pulp vesi¬ 
cles, and the first postcotyledo¬ 
nary leaves of the young seed¬ 
lings reduced to cataphylls. It 
differs from these Australian 
species of Citrus in having gray- 
green leaves, with palisade cells, 
stomates, and curious appressed 
hairs on both surfaces, and also 
in having the stomates of the 
twigs situated at the base of 
pits, in the usually 4-merous flowers, and in the much smaller fruits 
with only one or two seeds in a segment. 
Eremocitrus resembles the kumquat ( Citrus japonica Thunb.) in being 
a shrub bearing very small fruits and in its physiological adaptations 
to secure extreme winter dormancy. The kumquats differ decidedly 
from it in having usually 5-merous flowers, polyadelphous stamens, and 
a 5- or 6-celled ovary, short-stalked, fusiform pulp vesicles, and bifacial 
glabrous leaves. Eremocritrus shows little affinity to any other species 
of Citrus. 
From true Atalantias, such as A . monophylla (Roxb.) DC. and A. 
citrioides Pierre, having 2- to 4-celled fruits with pulp vesicles, Eremocitrus 
differs in having the stamens four times as numerous as the petals instead 
of twice as numerous. It also differs markedly from Atalantia in the 
structure of the leaves. It differs from the African cherry oranges 
(Citropsis spp.) in having simple leaves, two ovules in each cell of the 
ovary, stalked pulp vesicles, and in many anatomical characters. 
ju 
Pig. 2.— Eremocitrus glauca: Fruits and seed from Tambo, 
Queensland, Australia (S. P. I. No. 29537, James Pink, 
January, 1911). A, large pyriform fruit, natural size; 
B t small oblate fruit, natural size; C, cross section of a 
4-celled fruit, showing four seeds and numerous pulp 
vesicles, natural size; £>, a single, short-stalked pulp 
vesicle. X2; £, seed, showing rugose testa. XiM- 
Drawn by M. W. Gill. 
