Archivos de diario de agosto 2020

25 de agosto de 2020

Zaluzianskya capensis: Morphological and habitual similarities and differences from specimens in 3 widely separated localities

Z. capensis (Loc: Nondela, Northern Drakensberg, KZN)
*Hairy/ pubescent stems and leaf margins
*Elongated, lanceolate leaves, with smooth margins
*Inflorescence an indeterminate corymb, bracts sparsely hairy, mostly clasping

Z. capensis (Loc: Gouritz, Western Cape)
Z. capensis (Loc: Cape Peninsula, Western Cape)
*Hairy/ pubescent stems and leaf margins, shorter hairs scattered on leaf under and upperside and longer at base of bracts. Wide margin of variation.
*Leaves shorter, feintly oblong, margins with well defined, lobe-like teeth. Wide margin of variation.
*Inflorescence an indeterminate corymb, bracts densely hairy and recurved at tips

Conclusions:
The increased amount of hairs on Z. capensis in the Cape Peninsula is most probably a response to heat stress. Narrower, more compact river and drainage zones result in less shaded, moist habitats which this species thrives in, hence hairier plants in Cape Peninsula to diffuse sunlight.
The longer hairs bunched at the base of the bracts are likely a mitigative response to destructive herbivorous insects which target the nectary glands of the plant.
Differences in bract shape is possibly a response to increased numbers of nectarivorous insects in the Cape as a function of a more diverse availability of macro-nutrients and thus greater competition between flowering plants. More recurved bracts exclude all but the intended pollinator (Hawk Moth)
Differences in leaf and margin shape are probably a response to differences in seasonal ambient air temp and moisture levels, and the substantial variation in leaf and hair forms across a longitudinal spatial scale may indicate that Z. capensis is of itself a species complex and needs taxonomic revision.

Publicado el agosto 25, 2020 02:10 TARDE por anthonywalton anthonywalton | 4 observaciones | 0 comentarios | Deja un comentario