Monocots

The pollen morphologies of 18 native species
of Iridaceae from central Brazil Goia´s and Tocantins States
were investigated in order to understand the palynology
and taxonomy of some Brazilian Iridaceae. Pollen grains
were acetolyzed, measured, and studied via light microscopy
and scanning electron microscopy. The measurement
data was analyzed by descriptive and multivariate statistics.
The pollen grains are studied for the following characteristics:
monads, medium-to-large in size, bilateral
symmetry; heteropolar or isopolar; amb ellipsoidal or
spheroidal, biconvex, plane-convex or spheroidal in equatorial
view; 1-sulcate or zonasulculate; microreticulate or
reticulate, exine with smooth simplicolumellate muri,
narrow or wide, straight or curved, continuous or discontinuous;
rounded or polyhedral lumina, filled with or
without granules; sexine thicker than nexine, tectum with
similar thickness as nexine in most species. The results
allowed the distinction of genera and most species, showing
that pollen morphology can contribute to taxonomic
studies. The observed variation in pollen morphology of
the species occurring in the study region allowed us to
characterize the family as eurypalynous. These data
emphasize the importance of pollen morphology for identification
and diagnosis of genera in Iridaceae.

The phytodermology and leaf and scape anatomy were studied in wild populations of the Scilla verna complex (Scilla verna Hudson, S. ramburei Boiss, S. odorata Link, S. monophyllos Link., S. paui Lacaita, and S. merinoi Ortiz et al.) and several unrelated species (Scilla peruviana L., S. hyacinthoides L., S. lilio-hyacinthus L., and S. obtusifolia Poiret) in order to determine diagnostic characters to be used in intertaxa relationships. With the exception of leaf shape transection, all examined characters show little variation within taxa. Of the characters examined, those that show discrete variation between the studied taxa are the presence of trichomes, heterogeneity of chlorenchyma, presence of mucilaginous cavities, and epidermal extensions of the leaf margins. The close anatomical similarity observed between the Scilla taxa precludes its broad use for diagnosis. Within the complex, only Scilla monophyllos and S. paui could be distinguished by the anatomical features. No clear r...