PLUMBAGINEAE 57 



myia mortuorum L. i. {d) Syrphidae: 7. Eristalis intricarius Z.; 8. Platycheirus 

 sp. S, skg. C. Hymenoptera. 9. Colletes cunicularius L. $, po-clt";. (J). Hein- 

 sius (Holland), various flies (Ceratopogon sp. 5 ; Dilophus vulgaris Mg. 5 ; Hilara 

 chorica Fall. (?) ; Rhamphomyia sp. 5), a shoit-tongued bee (Prosopis communis 

 Nyl. S), and a butterfly (Coenonympha pamphilus L.) (Bot. Jaarb. Dodonaea, Ghent, 

 iv, 1892, pp. 84-5). Scott-Elliot (Dumfriesshire), a humble-bee, an Empid, a Muscid, 

 a hover-fly, and several Dolichopodids ('Flora of Dumfriesshire,' p. 142). 



1791. A. alpina Willd. (Kerner, 'Nat. Hist. PI.,' Eng. Ed. i, II, p. 358; 

 MacLeod, Bot. Jaarb. Dodonaea, Ghent, iii, 1891, p. 373.) — The flower mechanism 

 of this species agrees entirely with that of A. elongata. MacLeod says that crossing 

 and automatic self-pollination are successively ensured. According to Kerner, the 

 stamens of the homogamous flowers are so situated in the first stage of anthesis that 

 insects probing for the abundant nectar are obliged to rub against the pollen-covered 

 anthers, while the five styles with their stigmas are erect in the centre. Anthers and 

 stigmas then change places, the former turning towards the middle of the flower, 

 and the latter moving to its periphery. Should insect-visits fail, the styles ultimately 

 twist up spirally, move back to the centre, and become intertwined with the similarly 

 twisted stamens, so that the stigmas are brought into contact with any pollen that 

 may remain clinging to the latter. 



537. Statice Tourn. 



Flowers blue-violet in colour, and arranged in conspicuous corymbs ; the con- 

 cealed nectar secreted and stored up in the bases of the flowers. Sometimes hetero- 

 styly. 



1792. S. Limonium L. ( = S. Behen Drejer, and S. scanica Fries). (Mac- 

 Leod, Bot. Centralbl., Cassel, xxix, 1887; Knuth, ' Bl. u. Insekt. a. d. nordfr. Ins.,' 

 pp. 1Z4-5, ' VVeit. Beob. ii. Bl. u. Insekt. a. d. nordfr. Ins.,' p. 239, ' Bloemenbiol. 

 Bijdragen.') — The plants of this species I examined in the North Frisian Islands were 

 protandrous. The lobes of the corolla, as in Armeria, are held together by the calyx 

 during the first stage of anthesis, and the pollen-covered anthers project 1-2 mm. 

 from them. After these have withered, the styles, which are glabrous at the base, 

 elongate so that the receptive stigmas project from the entrance of the flower. 

 Crossing is therefore ensured by insect-visits, but should these fail, automatic self- 

 pollination is possible by means of the pollen which has fallen out of the anthers and 

 remains in the flowers. Geitonogamy appears to be brought about by the wind, for 

 masses of pollen are not infrequendy seen on and near the flowers. 



I observed only one type in the North Frisian Islands, but MacLeod describes 

 the following three varieties for the coast of Belgium (near Ter Neuzen and Nieuw- 

 port) :— 



(a) macrostyla n. var. : style 7-8 mm. long ; stigmatic papillae occupying 2-2^ 

 mm. of the tip of the style, not prominent; stamens short; extine with polygonal 

 markings. 



(b) brachyslyla n. var. : style 4-5 mm. long ; stigmatic papillae occupying only 

 f-i mm. of the end of the style, small but more prominent ; stamens long ; extine 

 without polygonal markings. 



(c) isostyla n. var. : stamens and style about the same length. 



