Zygophyllece ,] 
THE COLONY OE VICTORIA. 
99 
TRIBULUS. 
Tournefort, Institut. Hei Herbar . 141. 
Sepals 5, rarely 6, deciduous or persistent. Petals 5, rarely 6, as well as the sepals convolute 
in prseflorescence. Stamens generally 10, sometimes 5, rarely 6-9 or 12, all fertile or some sterile. 
Filaments capillary, those opposite the sepals frequently shorter than those belonging to the petals, 
provided externally with a basilar gland. Anthers two-celled; fertile ones with introrse longitudinal 
dehiscence. Ovary five-celled, girt by an hypogynous disk or surrounded at the base with scales. 
Ovules 1-4 in each cell, inserted to the central angle of the cell, pendulous. Style filiform. Stigma 
with 5 recumbent adnate lobes . Carpels normally 5, woody , indehiscent, coherent without a column , 
at last separating, generally with dorsal thorns, transversely 2-4-celled, or one-celled. Seeds tapering 
at the liilum. Testa membranous. Endopleura and albumen none . Embryo straight. Cotyledons 
plane-convex. Radicle conical. 
Herbs, dispersed over most tropical and subtropical countries, particularly of the eastern hemi¬ 
sphere, found besides in South Europe, South Africa, and extratropical Australia, frequently prostrate 
and annual. Leaves opposite or some or all alternate, abruptly pinnate, stipulate, one of each pair of 
smaller size. Leaflets small, herbaceous, entire. Pedicels solitary, in the axis of the smaller leaf or 
sometimes lateral. Petals tender, yellow, rarely white or below the middle red. Style often short. 
Carpels sometimes partially undeveloped, often tuberculate, rarely winged.— Linnd, Gem Plant 532; 
Adr. deJuss. in Memoir, chi Musdv/m d’Hist. Nat xii. 451-452, 1 14, /. 1; Endl. Gen . 1162; Tribu- 
lopsis, R. Brown in Stmt's Central Australia, ii. Append, p. 70. 
The sjoecies of Tribulus are readily segregated under two subgeneric divisions. The first of these, 
which may be designated Eutribulus, comprises all the formerly described species (with exclusion of 
those already separated as Kallstrosmias), and is characterized by leaves all or mostly opposite, by 
always fertile anthers and, except in rare cases, transversely celled carpels. The second subgenus, 
Tribulopsis, comprises Tribulus Solandri (Tribulopsis Solandri, R. Br. in Sturt's Exp. ii. App. p. 10; 
T. angustifolia, R Br. 1. c.), Tribulus Brownii (Tribulopsis pentandra, R Br. 1. c.) and Tribulus bicolor 
(Tribulopsis bicolor, F. M. Fragm. Phytogr. Austr. i. 47), all three species being restricted to tropical 
Australia, and remarkable for having constantly alternate leaves, fertile and barren anthers in often 
uncertain jnoportions, and normally one-celled carpels. These notes would seem clearly sufficient for 
generic distinction; yet in Tribulus alatus often less than 10 stamens occur, and 5 only in several 
oriental species, mentioned by Kralick, whilst in Tribulopsis Solandri and T. pentandra not rarely 
only fertile stamens, 5 in number, may be observed. The other main characteristic, that of the 
transversely celled carpels, becomes of doubtful value, when we in the North Australian Tribulus 
ranunculiflorus observe the carpels at least occasionally one-celled. The embryonic notes of Eutribulus 
and Tribulopsis are the same. The seeds of the former are, however, frequently depressed and placed 
nearly horizontally, whilst the seed of Tribulopsis is pendulous and more turgid. 
Tribulus terrestris, Linne, Spec. Plant. 554; Lcmark, Encycl. Methodique, t. 346; Kralick, in 
Annal. des Scienc . Nat. xi. 25; T. lanuginosus, Linne, Spec. Plant 553; Wight, Icon. Plant. Ind. Orient, 
t. 98; T. cistoides, Linne, Spec. Plant. 554; T. acanthococcus, F. M. in Transact . Phil. Soc . Viet. i. 9. 
Prostrate; leaves opposite or a few alternate, generally longer than the pedicels, consisting of from 
4-8 pairs of leaflets, which are oblique ovate-lanceolate or oblong or rarely ovate, and generally appressed- 
hairy beneath; forcers decandrous; anthers ovate, all fertile ; sepals almost lanceolate, oppressed, deciduous; 
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