91 
Order LXIX. CISTACEi^. The Rock-Rose Tribe. 
CiSTi, Juss. Gen. 294. (1789).— Cistoide^, Tabl. 3.219. (1799). — Cistine^e, DC. 
Prodr. 1. 2G3. (1824) ; Lindl. Synops. 36. (1829). 
Essential Character. — Sepals 5, continuous with the pedicel, persistent, unequal, 
the three inner with a twisted aestivation. Petals 5, hypogynous, very fugitive, crumpled 
in aestivation, and twisted in a direction contrary to that of the sepals. Stamens indefi- 
nite, hypogynous, distinct; anthers innate. Ovary distinct, 1- or many-celled ; oww/eswith 
the foramen at their apex; style single; stigma simple. Fruit capsular, usually 3- or 5- 
valved, occasionally 10-valved, either 1 -celled with parietal placentae in the axis of the 
valves, or imperfectly 5- or 10-celled with dissepiments proceeding from the middle of the 
valves, and touching each other in the centre. Seeds indefinite in number. Embryo 
inverted, either spiral or curved in the midst of mealy albumen. Radicle remote from the 
hilum. — Shrubs or herbaceous plants. Branches often viscid. Leaves usually entire, oppo- 
site or alternate, stipulate or exstipulate. Racemes usually unilateral. Flowers white, yellow, 
or red, very fugacious. 
Affinities. Distinguished from Violacese, with which they were for- 
merly confounded, by their indefinite stamens and inverted embryo; from 
Bixaceae by this last character, by their mealy albumen, habit, and not having 
the leaves ever dotted ; from Hypericacese by the latter character, and the struc- 
ture of the fruit ; they are akin to Papaveraceae by the genus Dendromecon. 
But their true station seems to be in the vicinity of Linaceae, Hugoniaceae, and 
Chlenaceae, to the first of which they approach by the genus Lechea. 
Geography. S. Europe and the north of Ajfrica are the countries that 
Cistaceae chiefly inhabit. They are rare in North America, extremely un- 
common in South America, and scarcely known in Asia. 
Properties. None, except that the resinous balsamic substance, called 
Labdanum, is obtained from Cistus creticus, and neighbouring species. 
GENERA. 
Cistus, Tourn. Lechea, L. 
Helianthemum, Tourn. Hudsonia, L. 
Order LXX. REAUMURIACEtE. 
Reaumurie.®, Ehrenberg in Ann. des. Sc. 12. 78. (1827). 
Essential Character. — Calyx 5-parted, surrounded externally by imbricated bracts. 
Petals 5, hypogynous. Stamens definite or indefinite, hypogynous, with or without an 
hypogynous disk ; anthers peltate. Ovary superior ; styles several, filiform, or subulate. 
Fruit capsular, with 2 to 5 valves, and as many cells, and a loculicidal dehiscence. Seeds 
definite, villous, erect ; embryo straight, surrounded by a small quantity of mealy albumen ; 
radicle next the hilum. — Shrubs. Leaves fleshy, scale-like, or small, alternate, without sti- 
pules. Flowers solitary. 
Affinities. Ehrenberg suggests {Ann. des Sc. 12. 78.) that Reaumuria 
and Hololachna, both of which have, according to him, hypogynous stamens, 
may constitute a httle group, to be called Reaumuriacese. To me the order ap- 
pears more nearly related to Hypericaceae than to either Mesembryaceae or Ta- 
maricaceae. From the former it chiefly differs in its succulent habit, and definite 
villous seeds, agreeing, in Reaumuria at least, even in the obliquity of the 
veins of the petals, and in the leaves being dotted. From Mesembryaceae its 
hypogynous stamens and seeds distinguish it ; from Tamaricaceae its plurilocu- 
lar ovary and distinct styles ; from Nitrariaceae its erect villous seeds, distinct 
styles, and hypogynous stamens. 
