Concentric rings of seed traps around individual parent plants of Lepidium campestre (Brassicaceae) used to document the distance and directional components of an individual's seed dispersion pattern in the absence of vegetation.
The federally endangered green pitcher plant (Sarracenia oreophila Sarraceniaceae) in flower. Thirty-five populations of this insectivorous perennial species remain in the southeastern U.S. Allozyme diversity is low in this species; small populations and geographically disjunct populations maintain the least genetic diversity.
Brighamia rockii (Campanulaceae) in full flower at ka'aloa Peak, Moloka'i, Hawaii. Both members of this endemic Hawaiian genus, B. rockii rom Moloka'i and its sister species B. insignis from Kaua'i and Ni'ihau, are federally endangered.
A hover-fly transports pollinia among flowers of Epipactis helleborine (L.) Crantz in England. Dominantly wasp-mediated cross-pollination has generated genetic structures consistent with random mating in both European and introduced North American populations.
A syrphid fly (Toxomerus spp.) visits a wild radish (Raphanus raphanistrum) flower. Syrphids are one of a variety of effective pollinators of wild radish, which also include bumble bees, honey bees, sweat bees, and cabbage butterflies. The strength of selection exerted by these pollinators and the heritability of floral traits in the field are lessened by a large degree of within-plant variation in these traits.
The three most abundant Venezuelan columnar cacti, from left to right, Pilosocereus lanuginosus (Linnaeus) Byles & Rowley, Stenocereus griseus (Haworth) Buxbaum, and Cereus repandus (Linnaeus) Miller. These species depend strictly on nectar-feeding bats for their pollination. Bat-mediated gene dispersal confers high levels of genetic exchange among populations of the three species, a process that enhances levels of genetic diversity within their populations.
A hawk moth (Basiothia schenki, Sphingidae) visiting the night-flowering Zaluzianskya natalensis (Scrophulariaceae; upper left) and a long-proboscid fly (Prosoeca ganglbauri, Nemestrinidae) visiting the day-flowering Z. microsiphon (lower right). These two plant species occur sympatrically on Mt. Gilboa, South Africa. Morphological and inter-simple sequence repeat (ISSR) data support the hypothesis that gene flow is occurring between these species despite their apparent ethological isolation.
Fruit color polymorphisms are striking examples of intraspecific genetic variation
in plants that can interact with animal associates such as seed dispersers.
Diaspores of the Australian desert shrub Acacia ligulata (Fabaceae)
are composed of a black seed (ca. 5 mm in length) surmounted by a colored, lipid-rich
aril (ca. 2.5 mm). The three color morphs-red, orange, and yellow-are dispersed
by both ants and birds.
A coastal prairie and UNESCO Biosphere Reserve north of Lincoln City, Oregon,
USA on the Pacific Ocean. The ungrazed promontory of the preserve supports a
diverse flora and fauna, including rare and endemic species. Color-coded organza
bags were used to retrieve inbred and outbred progeny from hand pollinations
of the rare Silene douglasii var. oraria (inset) for reintroduction.
Transplants of outbred progeny had higher survival over 5 years than the inbred
progeny in this headland (foreground), and seedling establishment was lowest
for the rare variety in natural and experimental plots. This case study will
facilitate the design of larger scale attempts at successful reintroductions.