Pollen Morphology of the Eucharideae (Amaryllidaceae)

Abstract

Eucharis, Caliphruria, and Urceolina form a monophyletic group of petiolate‐leaved, Neotropical Amaryllidaceae ecologically specialized to the understory of primary tropical rain forest below 2,000 m elevation. Pollen morphology of the three genera is surveyed. Pollen grains of all species of Eucharis, Caliphruria, and Urceolina are boat‐shaped elliptic, monosulcate, heteropolar, and bilateral in symmetry. Exine sculpturing is semitectate‐columellate and reticulate in all species examined. A transformation series in reticulum coarseness and pollen grain size is described. The large pollen grain with coarse reticulum of most Eucharis species is considered ancestral. The fine reticulation of Caliphruria is considered derived and the exine morphology of Urceolina is intermediate. Both of these genera have medium‐sized pollen grains. Exine dimorphism common to all Urceolina, but rare in Eucharis and Caliphruria, may be symplesiomorphous among those taxa exhibiting this morphology. The three genera are largely uniform in pollen grain ultrastructure, with completely ektexinous exines. Pollen grain size in Eucharis is not closely correlated with style length. Several wide‐ranging species show considerable intraspecific variation in pollen size. Parallelisms in pollen grain evolution among related tribes of Neotropical Amaryllidaceae are discussed.

Palynological study of the Venezuelan species of the genus Hymenocallis (Amaryllidaceae)

“…Our results about the general characteristics and ornamentation pattern of Hymenocallis pollen grains also agree with those of Erdtman (1966) and Huang (1972) for H. speciosa and H. declinata (H. caribaea), with those of Meerow and Dehgan (1985) for H. caroliniana and H. horsmannii, and with those of Meerow and Dehgan (1988) for H. latifolia. Likewise, some kind of equatorial exine polymorphism could also be seen in other genera belonging to the phylogenetically related Andean clade of the Amaryllidaceae.…”

“…Out of the Andean clade, the amaryllidaceous genus Hippeastrum Herb. and even the Old World Pancratium also present a reticulate dimorphic exine (Meerow and Dehgan 1988;Alves-Araujo et al 2007).…”

Palynological diversity of highly medicinal rare, endangered, and threatened plants from Western Himalaya, India

“…The pollen morphological characters of A. stracheyi (Amaryllidaceae) are described for the first time. The obtained results are in line with the previous studies on family Amaryllidaceae (Meerow and Dehgan, 1988;Oybak Donmez and Islk, 2008;Baser et al, 2019). The monocolpate pollen grains reported for T. govanianum (Melanthiaceae) (Figures 3,3b) in the present investigations have also been reported earlier (Nair and Sharma, 1965;Takahashi, 1983).…”