6o8 ANGIOSPERMAE—DICOTYLEDONES 



449. Helichrysum Vaill. 

 Ray-florets female, filiform, uniseriate ; disk-florets hermaphrodite, tubular. 



1440. H. arenarium Moench (=Gnaphalium arenarium Z). — The citron- 

 coloured involucral bracts make the heads of this species conspicuous. 



According to Warnstorf (Verb. bot. Ver., Berlin, xxxiii, 1896), only the variety 

 without filiform female ray-florets occurs at Neu-Ruppin ; the variety with orange-red 

 involucral bracts is not rare. The tip of each stylar branch possesses a bunch of 

 papillose sweeping-hairs, below which the stigmatic papillae are situated on the inner 

 surface. At first the style projects but little or not at all from the anther-cylinder, but 

 later on the diverging stigmatic branches project between the anthers so as to ensure 

 geitonogamy. The pollen-grains are golden-yellow in colour, rounded or ellipsoidal, 

 spinose, as much as 31 /a long and 23 /x broad. 



Visitors. — Herm. Miiller (Brandenburg) repeatedly observed the beetle Cocci- 

 nella quattuordecimpunctata L., resting on the heads (' Weit. Beob.,' Ill, p. 89). 



1441. H. bracteatum Andr. (Knuth, ' Bliitenbiol. Herbstbeob.,' ' Blutenbiol. 

 Notizen.') — 



Visitors. — The following were recorded by the observers, and for the localities 

 stated. — 



Knuth (Kiel Botanic Garden), a true wasp (Vespa vulgaris L.), 2 hover-flies 

 (Eristalis arbustorum Z., and Helophilus pendulus Z.), 2 beetles (Coccinella quinque- 

 punctata Z., and C. quattuordecimpunctata Z., especially the latter), and earwigs 

 (Forficula, dvg. the florets). Schletterer (Tyrol), the parasitic humble-bee Psithyrus 

 rupestris F., and the carpenter-bee Xylocopa violacea Z. 



1442. H. angustifolium DC. — 



Visitors. — Schletterer observed the following at Pola. — 



Hymenoptera. {a) Apidae: i. Eriades truncorum Z. ; 2. Eucera interrupta 

 Baer. ; 3. Halictus leucozonius Schr. ; 4. H. quadricinctus F. ; 5. H. scabiosae Rossi; 

 6. Megachile muraria Z. (3) Scoliidae: 7. Scolia hirta Schr.; 8. S. insubrica Scop. 



450. Artemisia L. 



Varies from class An to class Po. As Kirchner mentions (' Beitrage,' p. 67), 

 Delpino has shown that the group of Compositae constituted by him under the name 

 of Artemisiaceae, is anemophilous (' Studi]sopra un lignaggio anemofilo delle Composte, 

 &c.,' Firenze, 1871). The florets have become inconspicuous; the heads are often 

 pendulous ; there is no nectar; the pollen is dry, and scattered without the agency of 

 animals. 



Delpino describes various degrees of anemophily : the initial stage is found in 

 the genus Artemisia, and the adaptation is complete in the closely related genus 

 Oligosporus Cass, as well as in the groups Iveae and Ambrosieae. 



In the genus Artemisia (including Oligosporus) Delpino distinguishes the 

 following stages. — Artemisia (sens, stricl.) embraces species with heads containing 

 hermaphrodite as well as female florets ; the stigmatic branches of the former 

 diverge in the usual way, and ultimately become recurved. Oligosporus is purely 

 monoecious : in each head there are purely male florets along with female ones : 



