Order ROSALES 



By John Kunkki< Smai^l 



Herbs, shrubs, trees or vines, rarely aquatics iPodostemonaceae) , the 

 plants sometimes armed with prickles or thorns. I^eaves alternate, opposite 

 or whorled ; blades simple and entire, toothed, incised or parted, or com- 

 pound. Flowers predominantly perfect, sometimes monoecious, dioecious or 

 polygamous, regular, or typically irregular in Caesalpiniaceae ^ Krameriaceae 

 and Fabaceae, borne in open or congested clusters, the floral envelopes borne 

 on the margin of the manifest or well developed hypanthium, or rarely on the 

 torus below the gynoecium. Calyx of distinct or partially united sepals, regu- 

 lar, or decidedly irregular (^Krameriaceae and Caesalpiniaceae) or sometimes 2- 

 lipped iFabaceae), or rarely wanting {A Itingiaceae) . Corolla of as many dis- 

 tinct petals as there are sepals and regular or irregular, or of partially united 

 petals (^Caesalpiniaceae and Krameriaceae)^ or papilionaceous and with the keel- 

 petals mostly united (^Fabaceae) , or rarely wanting (Podostemonaceae , Altingia- 

 ceae, some Crassulaceae ^ Saxifragaceae^ Ham,amelidaceae ^ Rosaceae and Faba- 

 ceae). Androecium of as many stamens as there are sepals or petals, or twice 

 as many or more, borne on the margin of the hypanthium or rarely on the 

 torus below the gynoecium, sometimes partially reduced to staminodia ; fila- 

 ments distinct or partially united, sometimes monodelphous or diadelphous ; 

 antheis short or elongated, straight or bent, sometimes'^with glandular append- 

 ages. Gynoecium of a single carpel or of several distinct or united carpels, 

 sessile or stipitate. Ovary superior or partially or wholly inferior ; style termi- 

 nal, lateral or basal; stigma minute or inconspicuous. Ovules solitary, few 

 or many in each carpel, variously borne. Fruit a follicle, legume, loment, 

 capsule, pyxis, achene, drupe, pome, or berry, sometimes aggregate. Seed with 

 or without endosperm, sometimes arillate. 



Aquatic alga-like fleshy herbs, usually with spathe-like involucres. Fam. 1. Podostemonaceae. 

 Terrestrial or swamp plants, without spathe-like involucres. 

 Flowers reg^ular or nearly so (actinomorphic). 



Endosperm present, usually copious and fleshy: stipules 

 mostly wanting. 



Herbs. 



Carpels as many as the sepals: stamens as many as the 

 sepals or twice as many. 

 Plants succulent: carpels distinct or united at the 



base, opening lengthwise. Fam. 2. Crassulaceae. 



Plants not succulent: carpels united to the middle, 



circumscissile . Fam . 3 . Pentho r aceae . 



Carpels fewer than the sepals. 



Staminodia present: carpels 3 or 4, wholly united 



into a 1-celled gynoecium. Fam. 4. Parnassiaceae. 



Staminodia wanting: carpels mostly 2, distinct or 



partially united. Fam. 5. Saxifragaceae. 



Shrubs or trees. 

 Leaves opposite. 



I^eaves without stipules: gynoecium not surrounded 



by a disk. Fam. 6. Hydrange aceae. 



lyCaves with stipules: gynoecium surrounded by an 

 annular or a lobed disk. Fam. 7. Cxjnoniaceae. 



I^eaves alternate. 



Fruit a 2^5-celled capsule, or of more or less united 

 follicles. 



VOI.UMB 22, Part 1, 1905] 1 



