plant blog

location: moss oasis, endless barren waste

Euopsis granatina 

Lesser rockbud lichen, ground beef lichen

This arctic-alpine lichen grows on acidic rock in moist, sunny microhabitats, often mixed with or overgrowing Rhizocarpon lichens. It has a . . . huh, I don't really know how to describe the thallus form. Kinda scaley? Kinda plate-like? It generally falls into the "crustose" category, but it is like, bigger and thicker and rounder and clearly has its own unique shape thing going on. And that's not all! It has 2 different photobionts (Trebouxia green algae and Gloeocapsa cyanobacteria) but unlike most tripartite lichens which have a dominant green algal photobiont and cyanobacteria stored in smaller thallus subsections, E. granatina's thallus is mostly cyanobacterial, with small green algal subsections. Weeeird. The upper surface is a mottled red-brown, appearing gelatinous and almost fleshy when moist. It produces shiny red-brown apothecia (described as "recalling small garnets"). Just some globs of browned ground beef studded with garnets. Lichens are wild, man.

images: source | source | source

Biological structures aren't 3D printed like some folks may imagine, but are "seeded" or nucleated instead and use a set of rules that end up generating the whole structure with relatively little information compared to needing a whole 3D model to be stored. (Think of an ice crystal forming, allowing other molecules to attach to with, with the shape of that initial crystal informing the rest of the structure)

The pattern was discovered when Elijah Blum, then a high school intern at Cold Spring Harbor Laboratory in New York, noticed the Pilea’s fascinating leaves while plant-sitting for his sister. The leaves were speckled with water-venting pores called hydathodes, each fenced in by veins to form a mosaic. Blum, now at New York University, took the plant to his supervisor, computer scientist Saket Navlakha. “He showed the plant to me, and he said, ‘Look, the veins look kind of interesting here,’” Navlakha says. “And we sort of held it up to the light, and we saw that canonical Voronoi diagram.” In a Voronoi diagram, a surface is divided around a set of points so that every spot in a zone is closer to that zone’s point than any other. Urban planners use the same idea to map services such as fire departments, assigning houses to the nearest station. (Read more)