Jalap is a medicinal material derived from the storage root of a climbing plant. The source tissue and its extracted resin are distinct preparations.

Jalap resin is the resinous fraction obtained from jalap material. Extracting this fraction changes the chemical mixture relative to the intact storage root.

Rhubarb is a common name covering Rheum plants and distinct materials obtained from them. The medicinal root material is not the same plant part as the culinary leaf stalk.

Senna is a medicinal plant material obtained from certain Senna species, especially leaflets or fruits. Different parts and processed preparations require separate identification.

Logwood is the heartwood of the logwood tree, historically used as a source of coloring and medicinal material. Its extract is chemically distinct from intact wood.

Oak bark is bark material from oak trees, traditionally associated with tannin-rich preparations. Tissue identity and extraction conditions affect the resulting mixture.

Pareira root is a historical medicinal root material associated with Chondrodendron and related identifications. A trade name alone does not settle the botanical identity of every historical specimen.

Clove is the dried flower bud of the clove tree. Its volatile oil and solid tissues contribute different chemical fractions.

Chamomile is a common name applied to aromatic plants and their flower-head preparations. Several botanical sources occur in commerce, making source identity part of the definition of a preparation.

Calumba is a bitter root material associated with Jateorhiza palmata. The botanical source and the processed root are related but different objects of description.

Male fern is a traditional name for a fern and its medicinal rhizome material, especially Dryopteris filix-mas. The plant tissue contains a mixture of compounds.

Linseed is the seed of flax, valued for its oil and mucilage. The lipid-rich fraction and the water-binding seed-coat material have different physical properties.

Juniper oil is a volatile oil obtained from juniper material. Botanical source and the plant part used help specify its composition.

Anise oil is a volatile oil obtained from anise material. Its aromatic fraction differs from the complete chemical composition of the seed-like fruit.

Olive oil is the lipid-rich oil obtained from olive fruits. Its constituent triglycerides differ from the volatile compounds responsible for much of a plant’s aroma.

Volatile oil is an aromatic mixture of relatively volatile plant constituents, often called an essential oil. It differs chemically and physically from a nonvolatile storage fat.

Gum is a plant-derived, water-binding polysaccharide-rich material. Hydration can produce viscous solutions or dispersions.

Juice is liquid expressed or otherwise obtained from plant tissues. It is a mixture of dissolved and suspended constituents.

Creosote is a mixture obtained from distillation of organic material, historically including wood tar. Its composition depends strongly on origin and processing.

For $g(v,n)={\gamma }_K(v+v_K)n^4-(1-v)(H-n)M(v)$, with rapidly increasing saturating activation $M$, the zero-current nullcline satisfies $n^4/(H-n)=(1-v)M(v)/[{\gamma }_K(v+v_K)]$ in the physical strip. The left side increases strictly, so it defines one height for each voltage. Since $g_n>0$, its slope is $-g_v/g_n$. Rapid activation can make $g_v$ negative between two positive-slope current regimes, giving two descending attracting branches and an ascending repelling branch in the voltage–recovery phase plane. Sufficient activation steepness is a parameter condition; the shape is not forced by monotonicity alone.