154- CISTACEAIi — 155. BIXACKAI-; 365 



SUBORDER CISTINEAE 



FAMILY 154, CISTACEAE 



Leaves simple, entire. Flowers regular, hermaphrodite. Sepals 3 or 5, 

 with contorted aestivation. Petals 5, with contorted aestivation, deciduous. 

 Stamens hypogynous, 7 or more, usually numerous, unequal. Anthers opening 

 inwards or laterally. Ovary i-celled with 3 — 10 parietal placentas, or more or 

 less completely 3— lo-celled. Style simple or wanting , stigma large. Ovules 

 numerous, usually straight. Fruit a loculicidal capsule. Seeds albuminous ; 

 embryo curved. — Genera 5, species 75. North Africa and Cape Verde Islands. 

 (Plate 102.) 



1. Stamens partly (the outer ones) sterile. Carpels 3. Ovules (> — 12, in- 



verted. Style long. Undershrubs. — Species 5. North Africa. 



(Under Heliantliemum L.) Fumana Spach 



Stamens all fertile. Ovules straight 2 



2. Carpels 5 or 10. Funicle thread-shaped. Petals white or red. Shrubs or 



undershrubs. Leaves opposite, without stipules. — Species 15. North 

 Africa. Some are used as ornamental plants ; the resin of others 

 (ladanum) is employed in medicine and perfumery and as a fumigant. 



(Plate 102.) Cistus L. 



Carpels 3. 3 



3. Style long, usually kneed or sigmoid at the base. Funicle obconical. 



Embryo folded. Herbs or undershrubs. — • Species 40. North Africa 

 and Cape Verde Islands. Some are used as ornamental plants. " Rock- 

 rose." Helianthemum Adans. 



Style short and straight or wanting. Funicle thread-shaped or thickened 

 in the middle. Embryo coiled or hooked 4 



4. Funicle thread-shaped. Embryo coiled. Leaves, at least the upper ones, 



alternate, without stipules. — Species 3. North Africa. (Under 

 Heliantlie^nnm Tourn.) ........ Halimium Willk. 



Funicle thickened in the middle. Embryo hooked. Herbs. — Species 

 i(\ North Africa. (Under Helianthemum Tourn.) Tuberaria Spach 



FAMILY 155. BIXACEAE 



Shrubs. Leaves alternate, entire or lobed, palminerved, stipulate. Flowers 

 in terminal racemes, clothed with scales, regular, hermaphrodite. Sepals 

 5, free, glandular at the base, imbricate in bud. Petals 5, free, rose- 

 coloured, with imbricate or contorted aestivation. Stamens numerous, 

 hypogynous, free or shghtly united at the base. Anthers curved, opening 

 at the top by two short, transverse shts. Ovary superior, i-celled, with 

 2 parietal placetas. Ovules numerous, inverted. Style simple ; stigma 

 small, 2-lobed. Fruit 2-valved, usually prickly. Seed-coat red and fleshy 

 outside, hard within. Albumen copious. 



Genus i, species i {B. orcUana L.). Cultivated and naturalized in the 

 tropics. Yields fibres, dyes (arnatto), and medicaments. . Bixa L. 



