Nicandra physalodes (HUNZIKER, 1979)

Rodriguez, Ivana, 2000, Flower anatomy and morphology of Exodeconus maritimus (Solanaceae, Solaneae) and Nicandra physalodes (Solanaceae, Nicandreae): importance for their systematic relationships, Adansonia (3) 22 (2), pp. 187-199 : 191-194

Nicandra physalodes

Calyx

The sepals are sagittate, overlapping only at their base, 20-22 mm long and 14-15 mm wide. Their epidermis is covered by various trichomes: eglandular, simple, pluricellular with a length-

ened cuticle at its apex ( Fig. 5A ), and glandular with a head formed by 4-5 cells ( Fig. 5B ).

Corolla

The color is blue at the border with a white throat. The corolla is 30-32 mm long and 20- 21 mm wide. On the external epidermis, trichomes similar to those of the calyx are observed. The anatomical features of the calyx and corolla are very similar to those described for E. maritimus .

Androecium

The androecium is formed by five equal length stamens ( Fig. 5C ). The filaments are geniculate and pubescent at the base ( Fig. 5C ), where eglandular, simple hairs are especially abundant, form- ing compact pads ( Fig. 5C ). The anthers are 5-6 mm long and bear eglandular, simple trichomes throughout their surface. In this case, the endothecium is composed for two or three strata of cells with fibrous thickenings and the stomium is formed by two or three layers of small isodiametric cells with light colored contents ( Fig. 5D,E ). When such cells disorganize, the stomium zone does not have crystalline sand ( Fig. 5E ). On the other hand, the pollen sacs are all fertile with a completely normal endothecium, tapetum and pollen grains ( Fig. 5D,E ).

Gynoecium

The stigma is capitate, formed by five prominent stigmatic areas ( Fig. 6A,C ). The receptive

surface has pluricellular papillae ( Fig. 6C,D ), which are intertwined and contribute to the formation of stigmatic channels ( Fig. 6 B-D). The style is glabrous and lacks stomata. The ovary is composed by five carpels ( Fig. 7E ) and contains seven locules due to the presence of false septa at the base of the ovary ( Fig. 7F ). The parenchymatic cells of the ovary show mixed-shaped crystals: druse crystals, crystalline sand and amorphous glasses. The nectary at the base of the ovary is a ring with five soft swellings ( Fig. 7 A- D,F). The secretory tissue possesses 18-22 layers of cells ( Fig. 7C,D,F ) and 40 ± 5 stomata distributed only around the base of the nectary ( Fig. 7B ). Five dorsal and many lateral vascular bundles that ascend to the external wall of the ovary irrigate the nectary.

Vascularization

The vascular pattern of Nicandra flowers is equivalent to that described for Exodeconus maritimus . However, some differences can be observed. Nicandra has a siphonostele that is not divided into discrete vascular bundles. The vascular bundles of sepals, petals and stamens branch off without leaving lacunae. The calyx is irrigated by 15 vascular bundles (five are main bundles and the others lateral ramifications). The corolla has 15 vascular bundles (five are main bundles and the others lateral ramifications). The carpellary vascular system arises from the divided stele. The ovary is irrigated by 10 ventral bundles and 5 dorsal bundles, irrigating the style and the 5 stigmatic areas respectively. These observations agree with MURRAY’ S (1945) data.

Figures

Fig. 5. — Nicandra physalodes, androecium and flower trichomes: A, eglandular trichome; B, glandular trichome; C, stamens; D, E cross section of anther and detail of the stomium. Scale bars: A, B = 2 µm; C = 4 mm; D = 800 µm; E = 10 µm. Abbreviations: e = endothecium; s = stomium.

Fig. 6. — Nicandra physalodes, stigma: A, B, stigma and detail of stigmatic area (SEM); C, cross section of stigma; D, stigmatic channel. Scale bars: A = 200 µm; B = 50 µm; C = 250 µm; D = 10 µm. Abbreviation: ch = stigmatic channel.

Fig. 7. — Nicandra physalodes, ovary: A, B, ovary, nectary, and their stomata (SEM); C, D, longitudinal sections of ovary and nectary, respectively; E, F, cross sections at different levels of the ovary. Scale bars: A = 500; B = 20 µm; C, E, F = 800 µm; D = 100 µm. Abbreviation: n = nectary.