rE0TEACE2E. 



387 



base of which the equal perianth-leaves are inserted all on a level. 

 But in the second case it is oblique, and more or less bevelled ; and 

 this it is which causes the inequality of the perianth-leaves. These 

 are sometimes collected into a straight tube, more or less swollen in 

 the upper part, corresponding with the anthers ; sometimes they 

 form a bowed revolute sheath ; and two often separate from one 



G-re v illea Thelemanniana . 



Fig. 216. 

 Floriferous branch. 



Fig. 217. 

 (Flower f ) 



Fig. 218. 



Longitudinal section 



of flower. 



another along the edges at a variable height, to give passage to part 

 of the style (fig. 223), while its stigmatiferous apex is retained be- 

 tween the stamens 1 and the closed summit of the perianth. The gyn- 

 seceum is inserted on the centre of the receptacle in those species in 

 which it is most slightly irregular ; but where the base of the flower is 

 very oblique, that of the pistil becomes similarly oblique, often for a 

 considerable extent. 2 At the base of the foot of the ovary is a hypo- 

 gynous disk, annular, or more frequently forming a semicircular scale 

 or horseshoe on the placentary side of the gynajceum. The ovary 

 is unilocular, surmounted by a bowed or straight style ; this is 

 very variably dilated towards the apex ; and is surmounted by a 

 stigmatiferous head which may be straight or oblique, and convex, 



1 According to R. Beown, and H. Mohl (in 

 Ann. Sc. Nat., ser. 2, iii. 31.4, the pollen is flat 

 and triangular, with three large papillae on the 

 angles. We have observed it in O. glabrata 

 Meissn., Prodr. 391, n. 170 (O.Mariglesii Hort,; 

 — Manglesia glabrata Lindl., Swan, Riv., 37 ; 

 — M. cuneata Endl., Nov. Stirp. Dec, i. 25, not.) 

 (figs. 219-222). The grains have the same gene- 

 ral form as in Onagracea, with somewhat thin 

 edges. On each of the three obtuse angles is a 

 sort of cap, where a pollen-tube is sometimes 



produced very rapidly in contact with water. 

 The surface is smooth or very finely punctate, 

 sometimes prominent towards the centre of both 

 faces. There are grains of exceptional form, 

 quadrangular, or with the three angles unequal, 

 the smallest of the three sometimes disappearing 

 entirely. 



2 In this case the foot of the ovary app< trs 

 welded to one side of the perianth for a long way ; 

 but, it is really inserted along a ven long un- 

 equally developed, narrowly -bevelled receptacle. 



( • c 2 



