304 



XLV. ZYGOPHYLLE^. 



Tribulus terrenlrit. 



Tribuliu. 

 Vertical section of flower (mag.). 



CALYX 4-5-raerows, generally imbricate. PETALS kypogynous, usually imbricate. 

 STAMENS usually double the number of the petals, hypogynous ; filaments usually with a 

 scale inside. OVARY several-celled. FRUIT a loculicidal capsule, septicidally dividing 

 into cocci. EMBRYO exalbuminous, or enclosed in a cartilaginous albumen. Scentless 

 plants. LEAVES opposite, pinnate, stipulate. 



HERBS, SHRUBS or TREES ; branches often divaricate and jointed at the nodes. 

 LEAVES opposite, or alternate from the suppression of one, stipulate, compound, 

 sometimes pinnate or imparipinnate, sometimes 2- (rarely 1-) foliolate (Zygophyllum) ; 

 petiole sometimes flattened and winged ; leaflets sessile, entire, not punctate, often 

 inequilateral, flat, or fleshy, or terete ; stipules geminate at the base of the petioles, 

 persistent, sometimes spinescent. FLOWERS ? , regular or irregular, white, red or 

 yellow, rarely blue ; peduncles usually 1-2, springing from the axil of the stipules, 

 1 -flowered, ebracteate. SEPALS 5-4, usually persistent, free, rarely connate at the 

 base, aestivation imbricate or very rarely valvate (Seetzenia}. PETALS 54, very rarely 

 (Seetzenia), hypogyiious, free, aestivation usually imbricate, sometimes contorted 

 (Zygophyllum) ; disk hypogynous, convex or depressed, rarely annular (Tribulus), 

 sometimes inconspicuous (Fagonia, Guaiacum, &c.), or (Seetzenia). STAMENS 

 usually double the number of the petals, rarely equal (Seetzenia), inserted on the re- 

 ceptacle, 2-seriate, the outer opposite to the sepals ; filaments filiform, usually with 

 a small scale on the base within, or on their centre ; anthers introrse, dorsifixed 

 above their base, versatile, dehiscence longitudinal. OVARY free, sessile, or rarely 

 borne on a short gynophore (Larrea, Guaiacum), furrowed, angular, or winged, 4-5- 

 (rarely 10-12-) celled (Tribulus, Augea), or 2-3-celled (Zygophyllum), cells sometimes 



