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Ligusticum
porteri J. M. Coult. & Rose
Standardized Common
Name: Osha
Other Common Names: Chuchupate, Mountain
Lovage, Porter’s Lovage
Family: Apiaceae
(Umbelliferae)
Taxonomy: There are about
eight species of Ligusticum in North America, ranging from Canada and
the Pacific Northwest to northern Mexico. Other western species have similar
traditional uses and may be included within Osha, though not by the Herbs of
Commerce definition.
Description: Perennial herb,
0.5–1.0 m tall. Large leaves basal, long-petioled, (1–)2–3-ternate-pinnately
compound, ovate, to 30 cm long; leaflets (0.5–)2–5 cm long, highly dissected,
the lobes narrowly elliptic to lanceolate, obtuse or acute, sometimes toothed;
stem leaves few, smaller, with short broad sheathing petiole. Inflorescence a
large terminal compound umbel, subtended by 2 or more smaller, opposite or
whorled lateral compound umbels. Umbels 11–24-rayed, bractless or rarely with a
single linear bract; umbelets sometimes with few small, linear bracteoles.
Flowers tiny, white; sepals reduced, petals 5, stamens 5. Fruit a schizocarp of
2 mericarps, oblong, 5–8 mm long, laterally compressed; mericarps terete, with
5 prominent ribs; vallecular vittae 4–6, commissural vittae 8–10.
Parts
in Commerce:
Root with rootstock
Identification:
- Taproots 1 to
several, plump, seldom branching
- Upper portion of
taproot (rootstock) covered with fibrous leaf remains
- Lateral roots
cylindrical, irregularly bent
- Largest roots
may be 8–15(–20) mm in diameter
- Root bark pale
brown, not purple
- Root contains a
yellowish oil
- Cross-section of
root shows several-layered bark; broad ring of parenchyma, broken into
convoluted radiating strands; narrow ring of secondary phloem; large,
often off-center, multi-branched xylem (always over 25% of total root
diameter)
- Cross-section of
rootstock shows thin bark; large cortex parenchyma broken into separate
radiating strands; ring of numerous short xylem wedges; large pith,
sometimes with irregular air spaces
- All parts with irregularly
arranged secretory canals, the largest in the pith of the rootstock,
sometimes fusing to form very large canals
- Preliminary
evidence suggests that L. porteri may have smaller canals than
other species, single canals being frequently under 0.1 to 0.2 mm in
diameter, whereas other species have single canals of at least 0.15 mm and
often 0.5 mm or more
- Odor strong,
fragrant, somewhat resembling celery, slightly unpleasant but not fetid
- Taste bitter,
slightly numbing
Dried
roots are dark and longitudinally wrinkled; the pericycle frequently separates
and the vascular tissue splits into stiff strands. Dried cut surfaces may have
small orange beads of dried oil from the secretory canals.
Adulterants: Ligusticum
porteri is often confused with Conioselinum scopulorum J. M. Coult.
& Rose, which has a similar range, is very closely related, and has also
been used as a food and medicine. Though the aboveground portions of the two
species look very similar, Ligusticum has fibrous leaf base remains
covering the upper portion of the rootstock, whereas the rootstock of Conioselinum
is smooth and dark brown. The roots of C. scopulorum are smaller and
less odorous.
Also, C. scopulorum has at least one
partial circle of fiber bundles in the rhizomatous portion, though not the
root, and more layers of the root bark are corky. If adulteration of sliced
material with C. scopulorum is suspected, thin slices from the rootstock
portion may be checked for the presence of fiber bundles. Fiber bundles are
most easily observed by using a stain for lignin; the simplest of these is to
place thin hand-sections in a drop of phloroglucinol solution (1% to 2% in 95%
ethanol) and add a small drop of hydrochloric acid. In all roots, the xylem will
turn red; fiber bundles will show up as additional deep red spots at the
outside of the vascular tissue. This feature can be observed with a dissecting
microscope.
References:
Applequist WL. Root anatomy of Ligusticum
species (Apiaceae) sold as osha compared to that of potential contaminants. J
Herbs Spices Medicinal Plants. 2005;11(3):1–11.
Mathias ME, Constance L. Umbelliferae. North
American Flora. 1944–1945;28B:43–160,161–295.
Moore M. Medicinal Plants of the Mountain West.
Santa Fe, NM: Museum of New Mexico Press; 1979.
Sass JE. Botanical Microtechnique, 3rd
ed. Ames, IA: Iowa State University Press; 1958.
Welsh SL, Atwood ND, Goodrich S, Higgins LC. A
Utah Flora, 2nd ed. Provo, UT: Brigham Young University; 1993.
Figure 38: Ligusticum porteri root cross-section.