- Rhizome (Wikipedia)
In botany and dendrology, a rhizome (/ˈraɪzoʊm/; from Ancient Greek ῥίζωμα (rhízōma) ‘mass of roots’, from ῥιζόω (rhizóō) ‘cause to strike root’) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow horizontally. The rhizome also retains the ability to allow new shoots to grow upwards.
- Schläfli symbol (Wikipedia)
In geometry, the Schläfli symbol is a notation of the form {p,q,r,…} that defines regular polytopes and tessellations.