Xyridaceae occur in seasonally or permanently wet, usually acidic habitats, such as pine- and heath-lands, savannas, scrub vegetation, and bogs. Because of their relatively small stature these herbaceous species may appear straightforward to collect. However, the systematic utility of dried specimens can be greatly improved with supplemental material and notes.
Generally, entire plants of Xyridaceae can be collected and roots should be cleaned of accumulated substrate. Some species have sufficient mass that longitudinally trimming the plants will yield more uniformly pressed specimens. Most Xyridaceae have sympodial growth, and are often densely matted. A few individual stems should be pressed separately, and additional inflorescences for dissection should be collected for fragment packets. Collectors are advised that herbarium specimens of mixed collections are not uncommon because communities often include several species of Xyris.
Dissection and magnification are required to observe many of the taxonomically useful floral features of Xyridaceae. Most inflorescences and flowers have imbricate, lignified bracts and indurate sepals which make detailed study of herbarium specimens necessarily destructive. Moreover, the ephemeral corollas and closely associated staminodia and stamens are not well preserved on herbarium specimens. Thus, images of flowers at anthesis are very useful. Fluid-preserved material is most valuable for identification and comparative morphological study. A formalin-acetic acid-alcohol solution (FAA)1:1:18 v/v, using 50%–70% ethanol) is the preferred fixative. If not available, alcohol alone, other than isopropyl, can be used. If whole plants can not be fluid-preserved, plant portions should include important vegetative and reproductive features listed below.
Important morphological features
Notes on the following morphological features will enhance the value of the specimens, and aid in identification.
- Rhizomatous habit
- Leaf bases, juncture of leaf sheath and blade, leaf apex
- Leaf surrounding the peduncle
- Grooves and torsion of the peduncle
- Color of stoma field on floral bracts (Xyris)
- Compound inflorescence, if present
- Anther dehiscence orientation
- Color of anthers
- Orientation of the style and stigma
- Color of the style and stigma
Ecological notes:
- Amount of water present
- Time of day flowers are open
- Presence of floral odor
- Other Xyridaceae species in the community