A low\ glabrous\ evergreen shrub\ "4#Ð09Ð14Ð"39# cm tall[ The ~owering stems are decumbent to erect\ spar! ingly branched\ arising from a creeping\ woody rhi! zome "Warming 0897^ Fl[ Eur[ 2^ Fl[ Br[ Isl[^ Hegi Fl[ 0\ ed[ 2^ Rameau et al[ 0882^ Stace 0886#[ The leaves are narrow\ alternate\ subsessile\ coriaceous\ oblong to linear\ dark green above\ silvery!glaucous beneath\ 09Ð39 × 1Ð7 mm "Barvaux 0847^ Fl[ Eur[ 2^ Fl[ Br[ Isl[^ Rameau et al[ 0882^ Stace 0886#[ They are mucronulate "Anderson 0850# or acute to apiculate "Fl[ Eur[ 2#^ their margins are usually revolute "Fl[ Br[ Isl[^ Rameau et al[ 0882#[ The ~owers are pentamerous "Barvaux 0847^ And! erson 0850^ Hegi Fl[ 0\ ed[ 2#\ in very short\ umbel! like terminal racemes of 1Ð6Ð"01# "Warming 0897^ Fl[ Eur[ 2^ Rameau et al[ 0882#[ However\ Warming "0897# reported 3!merous ~owers in Finnmark and in Greenland[ The pedicels are pinkish\ 1Ð3 times as long as the corolla "Barvaux 0847^ Fl[ Br[ Isl[^ Hegi Fl[ 0\ ed[ 2#^ they are 6Ð04 mm long and slender "Fl[ Eur[ 2#[ The sepals are persistent\ triangular\ reddish\ acute\ about 0[4 mm long "Anderson 0850^ Fl[ Eur[ 2# and connate at base "Fl[ Eur[ 2#[ Two bracteoles lie at the extreme base of the pedicel\ concealed by a bract "Fl[ Eur[ 2#[ Corolla globose!urceolate with 4 recurved teeth^ drooping "Webb 0856#\ inclined or pendent "Fl[ Eur[ 2#\ bright pink at _rst\ fading almost to white[ It reaches 4Ð7 mm long "Warming 0897^ Barvaux 0847^ Anderson 0850^ Fl[ Br[ Isl[^ Hegi Fl[ 0\ ed[ 2^ Rameau et al[ 0882# and it continues to grow during ~owering "Warming 0897#[ The interior of the corolla is covered with erect\ usually somewhat upturned\ hairs that extend to the margin of the limb "Warming 0897#[ The stigma lies just at or immediately within the throat of the corolla\ and the 09 anthers\ which are at the level of the middle of the pistil and the corolla\ bend inwards towards the style "Warming 0897^ Barvaux 0847^ Hegi Fl[ 0\ ed[ 2^ Rameau et al[ 0882#[ The _laments are strongly swollen just above their slender short bases and are covered with fairly long hairs along the greater part of their length "Warming 0897^ Anderson 0850#[ The anthers are covered with small protuberances^ they open at the apex by two pores of irregular shape "Warming 0897^ Hegi Fl[ 0\ ed[ 2#[ The two apical appendages are as long as the anthers\ glabrous and slightly curved "Warming 0897^ And!

Biological flora of the British Isles

The Natural History of Pollination.

Outline of the classification of flowering plants (Magnoliophyta)

SUMMARY
The role of the involucral bracts of the Compositae capitulum in fruit dispersal, the behaviour of the pappus of composite fruits to changes in humidity, and the presentation of the achene-pappus units for wind dispersal, are briefly reviewed. Arguments put forward in the literature for and against the effectiveness of the pappus in facilitating wind dispersal are presented. A method is described for comparing the dispersal efficiency of achene-pappus units of selected composites. The computed trajectories for fruits of selected species under the independent effects of wind speed and plant height, wind speed and boundary layer, and the combination of these with convection velocity are given.

It is shown that the efficiency of dispersal is determined more by the fine details of the pappus geometry, which directly affects its aerodynamic properties, than by the size ratio of pappus to achene. Under steady horizontal winds, increased height of fruit release increases dispersal distance. Reported patterns of wind dispersal are discussed in terms of air movement, flight path interference by neighbouring plants and, for some species, the fruit dissemination mechanism.

While increased wind velocities increase the trajectory distance, dispersal of many composites is hampered by the pappus response to humidity. Increased dispersal distances are given by steady convection currents, whereas turbulence may either curtail or prolong transportation.

The apparent inefficiency of wind dispersal reported under field conditions is explained by the combined effects of these various environmental factors upon the dispersal units during the period of dissemination.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1973.tb04415.x

The dispersal effectiveness of the achene-pappus units of selected Compositae in steady winds with convection

s. Albuquerque, New Mexico, August 12-16, 2001. Botanical Society of America. Pp. 132. Panero, J.L., Baldwin, B.G., Schilling, E.E. & Clevinger, J.A. 2001c. Molecular phylogenetic studies of members of tribes Helenieae, Heliantheae, and Eupatorieae (Asteraceae). 3. General systematics and proposed taxonomic changes in current classification. In: Botany 2001 Abstracts. Albuquerque, New Mexico, August 12-16, 2001.s. Albuquerque, New Mexico, August 12-16, 2001. Botanical Society of America. Pp. 132. Panero, J. & Funk, V.A. 2002. Toward a phylogenetic subfamilial classification for the Compositae (Asteraceae). Proc. Biol. Soc. Wash. 115: 909-922. Pelser, P.B., Gravendeel, B. & Meijden, R. 2002. Tackling speciose genera: species composition and phylogenetic position of Senecio sect. Jacobaea (Asteraceae) based on plastid and nrDNA sequences. Amer. J. Bot. 89: 929939. Raven, P.H. & Axelrod, D.I. 1974. Angiosperm biogeography and past continental movements. Ann. Missouri Bot. Gard. 61: 539-673. Robinson, H. 1983. A generic review of the tribe Liabeae (Asteraceae). Smithsonian Contr. Bot. 54: 1-69. Robinson, H. 1999. Generic and subtribal classification of American Vernonieae. Smithsonian Contr. Bot. 89: 1-116. Rzedowski, J. 1972. Contribuciones a la fitogeografia floristica e historica de Mexico. III Algunas tendencias en la distribucion geografica y ecologica de las Compositae mexicanas. Ciencia (Mexico) 27: 123-132. Schmidt, G.J. & Schilling, E.E. 2000. Phylogeny and biogeography of Eupatorium (Asteraceae: Eupatorieae) based on nuclear ITS sequence data. Amer. J. Bot. 87: 716726. Scotese, C.R. 2002. PALEOMAP website. (http://www.scotese.com) Skavarla, J. 1977. Pollen Morphology. In: Heywood, V.H., Harborne, J.B. & Turner, B.L. (eds.), The Biology and Chemistry of the Compositae. Vol. 1. Academic Press, Lon-

Everywhere but Antarctica: using a supertree to understand the diversity and distribution of the Compositae.

I the Compositas the mechanism involved in the presentation of pollen to the insect visitor includes both styles and stamens. These essential oi'gans ai-e discussed, therefore, in the present chapter, but for convenience the variation in structure of styles and stamens is described and discussed in separate sections, while their functions in the pollen-presenting mechanism is considered partly in section D of the present chapter and partly in Chapter III which deals with the irritability of the mechanism.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1918.tb07269.x

James Small

Papers

The origin and development of the compositæ.

The Pollen-presentation Mechanism in the Compositae

The origin and development of the composit

The origin and development of the compositæ.: chapter vi.

On the Floral Anatomy of some Compositæ.