Plant blindness or the inability to notice plants in one’s everyday life is a complex phenomenon in the field of science education. Although plant blindness is well documented in the literature, the underlying factors, whether biological or cultural, are still under research. Here I focus on its biological basis. That is, I review and discuss how plants’ own inherent characteristics cause effects on human visual and cognitive processes. Animals versus plant differences in human attention and memory are also addressed. Grounded on that knowledge, some recommendations for effective practice in plant science education emerge. I conclude that only when we understand human-plant relationships will we know how to enhance teaching and learning about plants.

Individuals of the aquatic oligochaete species Stylodrilus heringianus Claparède, 1862 were collected across a part of this species’ distribution range in Sweden, Estonia, Great Britain and Spain to test whether they represent a single metapopulation or several separately evolving lineages. Using sequences of the barcoding gene cytochrome c oxidase subunit I (COI) and two nuclear genes (internal transcribed spacer region and histone 3), three different approaches were conducted: pairwise distance-method, Bayesian inference and network analysis. Both the COI phylogeny and network analyses were concordant in recovering six haplotype clusters, which showed a maximum genetic distance of 7.7% (K2P) among each other. Nevertheless, nuclear genes failed to confirm any lineage separation, and we conclude that the sampled specimens all belong to the same species. A phylogeographic history with allopatric divergence and secondary contact is suggested to explain this intraspecific pattern of mitochondrial divergence and nuclear non-divergence. The study shows that a mitochondrial single-locus approach can be problematic for the accurate delimitation of species, and we emphasise the need for nuclear genes as supplementary markers, when taxonomic resolution is assessed with COI barcodes.

Partial sequences of the mitochondrial genes 16S rRNA and cytochrome c oxidase subunit I (COI) were used (1) to resolve the internal relationships of the subfamily Tubificinae (Annelida : Clitellata) and (2) to test the existence of cryptic species within the stygobiont oligochaete Troglodrilus galarzai (Giani & Rodriguez, 1988). Phylogenies were estimated using maximum likelihood, Bayesian inference and parsimony. Although trees were incompletely resolved at intergeneric level, a close relationship between Heterochaeta Claparède, 1863 and Troglodrilus Juget, des Châtelliers & Rodriguez was revealed, and the separation of Lophochaeta ignota Štolc, 1886 and Heterochaeta costata Claparède, 1863 from Tubifex Lamarck, 1816 was corroborated by mitochondrial molecular data. Maximum genetic divergence between allopatric populations of T. galarzai was 18% for COI (uncorrected pairwise distance), suggesting cryptic speciation within this nominal species.