THALAMIFLOEJE. 451 



Diagnosis. — Herbs or tindershrubs, much branched, with 

 opposite exstipulate leaves, and sessile flowers. Calyx tubular, 

 furrowed, persistent. Petals unguiculate, 4 or 5, hypogynous. 

 Stamens hypogynous, distinct. Ovary superior, 1 -celled, with 

 parietal placentas. Fruit capsular, 1 -celled, enclosed in the 

 calyx, and dehiscing in a septicidal manner. Seeds numerous ; 

 embryo straight, erect, in the middle of albumen. 



Distribution, ^'c. — The plants of this order are scattered over 

 the globe, except in tropical India and North America, but they 

 chiefly occiu' in the south of Europe and north of Africa. Ex- 

 amples of the Genera: — Frankenia, Beatsonia. There are 24 

 species mentioned by Lindley. 



Properties and Uses. — Unimportant. They have been reputed 

 mucilaginous and slightly aromatic. The leaves of a species of 

 Beatsonia are used at St. Helena as a substitute for tea. 



Natural Order 24. Tamaricace^. — The Tamarisk Order. 

 Character. — Shrubs or herbs. Leaves alternate, scaly, en- 

 tire, usually pitted. Flowers in spikes or racemes. Calyx 4 or 

 5-parted, persistent, imbricate. Petals distinct, adherent to 

 the cal}^, withering, imbricate. Stamens hypogynous, as many 

 as the petals, or twice as numerous, distinct or united ; anthers 

 introrse. Ovary superior ; styles 3 ; ovuhs numerous. Fruit 

 1 -celled, dehiscing by three valves in a loeulicidal manner ; henc* 

 each valve bears a placenta in its middle, or sometimes at its 

 base. Seeds numerous, comose, exalbuminous ; embryo straight ; 

 radicle next the hilum. 



Diagnosis. — Shrubs or herbs, with alternate entire scale-like 

 leaves. Calyx 4 — 5-parted, imbricate, persistent. Petals dis- 

 tinct, and attached to the calyx, withering, imbricate. Stamens 

 hypogynous ; anthers introrse. Ovary superior with distinct 

 styles. Fruit dehiscing loculicidally by 3 valves. Seeds nume- 

 rous, comose, without albumen, and having a straight embryo, 

 with the radicle towards the hilum. 



Distribution, ^'c. — The plants of this order usually grow by 

 the sea-side, or sometimes on the margins of rivers or lakes. 

 They are most abundant in the basin of the Mediterranean, and 

 are altogether confined to the northern hemisphere of the Old 

 World. Examiiles of the Genera : — Tamarix, Myricaria. There 

 are 43 species. 



Properties and Uses. — The bark of these plants is astringent, 

 slightly bitter, and tonic. The ashes of some species of Tamarix 

 contain much sulphate of soda. 



Tamarix— T. mannifera produces a saccharine substance, which is known 

 under the name of Mount Sinai Manna. This is considered by Ehrenberg 

 as an exudation produced by a species of Coccus, which inhabits this plant. 

 T. gallica, orientalis, and some other species of Tamarix are liable to the 

 attack of insects, which produce galls on their surface. Theso galls are 

 astringent, and are sometimes used in medicine and as dyeing agents where 

 astringent substances are required. 



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