Apiaceae - Umbelliferae

Heracleum lanatum
Heracleum lanatum
©David Williams RNR 202



Aethusa cynapium
Uppsala



Bowlesia incana
UofAz

Apiaceae or Umbelliferae:
The "archtypal" carrot family pollen is tricolporate and peanut-shaped with obvious internal thickenings surrounding a large endopore in the equatorial region, with short straight furrows. Umbelliferae pollen is often stirate, but also may be rugulate or psilate. However, the sculpture is not generally visible in light microscopy (without oil immersion), and the columellae may form a reticulate pattern. The grains are strongly prolate and typically parallel-sided to constricted in the equatorial region.
The pollen grains are relatively distinctive and identification to the species level is likely. However, the widespread group, with relatively rare pollen is not routinely used in ecological interpretations, so continued use of the broad "Apiaceae" or "Umbelliferae" pollen type seems likely to persist in routine pollen analysis.

Plants:
A ubiquitous circumboreal family of 300 genera and 3000 species, mostly herbs with alternate lobed to compound leaves and sheathing petioles. Fruits notably oily and the herbage usually strongly scented. Fruits born in distinctive heads (umbels). The Umbelliferae contains many economically important plants including celery, chervil, parsley, dill, caraway, coriandeer, cumin, fennel, and anise; and some famous poisonous ones - water-hemlock (Conium, Cicutaria)

Pollen light micrograph:
The internal thickenings around the pores (costae) are one of the most characteristic features of Umbelliferae pollen. The pores (thin areas) may be circular, elliptical, or rectangular in plan view, with the long axis perpendicular to the polar axis of the grain. The thickenings may more-or-less fuse to form two continuous bands encircling the grain poleward of the pores - costae aequatorialae.
Grains that are strongly constricted in the equatorial region may have protruding pores or pronunced polarly-elongated ridges in the equatorial region.
In polar view, the grains are often triangular, with the furrows at the apices of the triangle (angular) or in the sides of the triangle (interangular).

Pollen scanning electron micrograph (SEM)
The characteristic internal thickenings (costae) of Umbelliferae pollen are not visible in SEM's, but the sculpturing and protruding pores are more obvious than in light microscopy.

Production and Dispersal:
This insect pollinated family has low production and poor dispersal, but the plants are so widespread that a few grains appear in many samples.

Preservation:
Good. The walls are thick and the costae are apparent in poorly-preserved grains.

Fossil Occurrence:
Tertiary - common from Miocene onward.

References:
  • Punt, W. 1984. Umbelliferae. pp. 155-363. in Punt, W, and Clarke, G.C.S. The Northwest European Pollen Flora 37. Elsevier, Amsterdam. (reprinted from Review of Palaeobotany and Palynology 42.)

Links
Owen Davis 6/02