Huang F., Guo W., Structural and mechanical properties of the spines from Echinocactus grusonii cactus, Journal of Materials Science, 2013, 48(16):5420-5428, doi: 10.1007/s10853-013-7335-4
Microscopy, X-ray microanalysis, nanoindentation and tensile testing describe Echinocactus grusonii spine organisation. The paper compares measurement directions, specimen preparation and fracture appearance. Distinguishing local wall response from axial tension supports interpretation of the fibrous structure.