(7) Nora Barlow, "The Inheritance of the Three Forms of the Trimorphic
Species," 13 (1923): 133-146.
Capitula homogamous or heterogamous, discoid, disciform, ligulate, or radiate, isomorphic or heteromorphic with dimorphic, sub-dimorphic, or rarely with trimorphic florets, with one to numerous florets; receptacle epaleate to paleate, glabrous, pilose, setose to fimbriate; involucre uniseriate to multiseriate.
Capitula with dimorphic or trimorphic florets; when trimorphic, the intermediate florets with corollas bilabiate to filiformbilabiate, as long as the styles or longer; staminodes generally present Gerbera 41b.
Of the 30 populations sampled, 70% were trimorphic, 20% dimorphic, and 10% monomorphic [ILLUSTRATION FOR FIGURE 1 OMITTED].
In addition to the frequent loss of the M morph, trimorphic populations exhibited major departures from even morph frequencies.
Florets dimorphic to trimorphic
; marginal florets female generally with filiform to well developed staminodes, corolla bilabiate with an expanded outer lip, rarely minute; intermediate florets (when present) female with or without staminodes, corolla bilabiate, rarely filiformbilabiate, as long as the style or longer; central florets bisexual, corolla bilabiate; anther apical appendages acute, tails smooth; style bilobed to bifid, dorsally papillose.
We determined these equilibria by running simulations until the proportion of populations remaining trimorphic consistently fluctuated around a constant value (usually 100-300 yr).
In addition to the loss of morphs from populations, stochastic processes are expected to increase the degree of morph-frequency variation among trimorphic populations.
salicaria population in southern Sweden (Andersson 1994), nor could it by itself explain deviations from even morph frequencies in trimorphic
For Q slightly above 1, the dimorphic distribution is not stable, and we conjecture that, instead, the ESS is trimorphic
for [Mathematical Expression Omitted] just above 1, followed by bifurcations to 5, 7, .
In spite of high self- and intramorph fertility, trimorphic
populations typically outcross (Glover and Barrett 1986; Barrett and Husband 1990) with most outcrossed progeny resulting from intermorph matings (Barrett et al.
We used Monte Carlo simulations to determine the effective population size below which genetic drift would overcome the effects of frequency-dependent mating on the maintenance of trimorphic