ROSACEA. 375 



the petals, and the other ten are placed one on either side of each 

 of the latter set. Every stamen consists of a free filament, inflexed 

 in the bud, and an introrse two-celled anther, dehiscing longitudinally.' 

 The edge of the disk projects internally to the androceum into ten 

 more or less prominent glandular lobes, two superposed to each sepal. 

 The gynseceum consists of five carpels, each superposed to a petal (fig. 

 441), and composed of a free one-celled ovary tapering above into a 

 style which is sHghtly dilated at the tip and covered with stigmatic 

 papillae. In the internal angle of the ovary is a longitudinal placenta 

 with two lips, each bearing an indefinite number of horizontal or 

 obliquely descending anatropous ovules.- The multiple fruit consists 

 of five many-seeded follicles, surrounded by the persistent receptacle 

 and calyx. The seed contains within its membranous coats a fleshy 

 exalbuminous embryo. All the species of Spircea analogous to the 

 one just studied,' representing the most perfect types of the 

 genus, possess alternate simple stipulate or exstipulate leaves, and 

 corymbose flowers.^ But of about fifty species of this genus there 

 are many, which, with the general organization of those we know, 

 present in several of the floral organs various modifications which it 

 is now our duty to mention. 



The flowers are sometimes tetramerous.' The form of the recep- 

 tacle may vary somewhat ; it may be pouched or bell-shaped, or it 

 may form a shallow cupule ; it is very rarely like a long tube or 

 an inverted cone.*^ The aestivation of the sepals may be imbricate. 

 There are pretty often as many as twenty-five or thirty stamens, 

 and in some few cases more.' There are rarely less than fifteen.' 



• The pollen of several species of Spiraa has below the insertion of the pedicel, but some 



been described by H. Mohl {Ann. Sc. Nat., ser. way up the latter, which was at first axillary 



2, iii. 340) as consisting of ovoidal papillate to it and has carried it up; sometimes the 



grains with three grooves ; in water they are bract is even close against the base of the 



spherical, with three bands ; the species were S. flower. 



Ulmaria, S. sorhifoUa, S. oppositifoUa, and S. * Sometimes they have six sepals and six petals, 



Filipendula (without papillje). or even more, as in S. Filipendida, which has 



- They have only a single coat in this species, often seven, eight, or nine petals, 



as in several others that I have examined ; it ® " In S. parvifolia Benth., specie admodum 



would be worth while to study all the cultivated singulari, calycis tubus obconicus est, lobis 



Spiraas from this point of view. exalte valvaiis." (B. H., Gen., 612.) 



3 They form the two sections Chamadri/on ' Either because there are five in front of 



(See., op. cit., 542) and Spiraria (See., op. cit., each petal (where we only found three in ^. Ian- 



544), united by Endlichee (loc. cit,, b) into a ceolata), or because there are two or three in 



single one. front of each sepal inste:id of only one. 



^ Or they may be in usually short racemes. In * In Eriogyna, which we were the first 



S. lanceolata, as in many other species, the pe- (Adansonia, vi. 6) to place near Spircra, the 



dicel does not appear to spring from the axil of stamens have been said to cohere by the bases of 



a bract, for this is not found on the chief axis, their filaments. This is not constant, and is in 



