336 MANUAL OP BOTANY 



a pome, 1 — 5-celled or rarely spuriously 10-celled. Seeds 

 erect or ascending. Illustrative Genera : — Pyrus, Linn. ; 

 Crataegus, Linn. 

 Distrihution and Numbers. — The Ohrysohalcmece are princi- 

 pally natives of the tropical parts of America and Africa. The 

 DrupacecE are almost exclusively found in the cold and tem- 

 perate regions of the northern hemisphere. The EosecB and 

 SamguisorhecB are also chiefly natives of cold and temperate 

 climates, although a few are, found within the tropics. The Pomece 

 occur only in the cold and temperate regions of the northern 

 hemisphere. The order Rosacese comprises about 1,000 species, 

 of which about one-half belong to the sub-order Eosese. 



Properties and Uses. — The plants of the order are principally 

 remarkable for their astringency, and for their succulent edible 

 fruits. The seeds, flowers, leaves, and young shoots of many 

 of the BrupacecB and Pomece, when moistened with water, yield 

 hydrocyanic acid ; hence parts of such plants are sometimes 

 poisonous. All other Eosaoeae are entirely devoid of poisonous 

 properties. 



Order 122. SaxifeagacBjB, the Saxifrage Order. — Charac- 

 ter. — Herbs with alternate leaves, which are entire or lobed, 

 stipulate or exstipulate. Calyx of 4 or 5 sepals, which are more 

 or less united at the base, inferior or more or less superior. 

 Petals 4 or 5, perigynous, imbricate, alternate with the lobes 

 of the calyx, sometimes wanting. Stamens 5 — 10, perigynous 

 or epigynous ; anthers 2-celled, with longitudinal dehiscence. 

 Disc usually evident, either existing in the form of 5 scaly 

 processes, or aimular and notched, epigynous or perigynous. 

 Ovary superior or more or less inferior, usually composed of two 

 carpels, united below, but more or less distinct towards the 

 apex ; 1- or 2-celled ; styles equal in number to the carpels, dis- 

 tinct, diverging. Fruit capsular, 1 — 2-celled, usually mem- 

 branous. Seeds small, numerous ; embryo in the axis of fleshy 

 albumen, and with the radicle towards the hilum. 



Diagnosis. — Herbs with alternate leaves. Calyx inferior 

 or generally more or less superior, 4 — 5-partite. Stamens 

 perigynous or epigynous. Ovary superior or more or less 

 inferior, composed of 2 carpels united at the base, and diverging 

 at the apex; styles distinct, equal in number to the carpels. 

 Fruit capsular, 1 — 2-celled. Seeds numerous, small, with 

 fleshy albumen. 



Bentham and HooTcer include the succeeding orders, Fran- 

 coacecB, Escalloniacece, Philadelphacem, HydrangeacecB, Hen- 



