POLLEN FLORA OF PAKISTAN – LXVIII
Pollen morphology 20 species of the family Alliaceae from Pakistan has been examined by light and scanning electron microscope. Pollen grains are usually bilateral, hetropolar mostly boat shaped, sexine thicker tor thinner than nexine. Tectal surface is mostly rugulate foveolate or subpsilate rarely reticulate. On the basis of apertural types 3 distinct pollen types are recognized, viz., Allium fedtschenkoanum –type, Allium grifthianum-type and Allium roylei-type.
BIOLOGICAL VALUE AND MORPHOLOGICAL TRAITS OF POLLEN OF SELECTED GARLIC SPECIES ALLIUM L.
Summary This study was conducted in the years 1997 1999. From the collection of the UMCS Botanical Garden, nine species of garlic were selected (A. aflatunense, A. atropurpureum, A. caeruleum, A. cernuum, A. ledebourianum, A. lineare, A. sphaerocephalon, A. victorialis, A. ursinum) and one subspecies (A. scorodoprasum subsp. jajlae). Pollen grain viability was evaluated on microscopic slides stained with acetocarmine, germination abi lity on the agar medium and measurements of grains were made on glycerin jelly slides. The studied species were characterized by high pollen viability (87 99%) what indicates the great value of garlic flowers as a source of protein rich feed for honey bee and wild pollinating insects. Very low germination of pollen on the agar medium was recorded. The length of the equatorial lon gitudinal axis ranged from 24.3 µm to 37.5 µm and it allowed pollen of most garlic species to be classified as medium sized grains and only the pollen of A. caeruleum and A. cernuum was included in the group of small sized grains.
Fruit differentiation, palynology, and systematics in theScabiosa group of genera andPseudoscabiosa (Dipsacaceae)
Fruits ofDipsacaceae are single-seeded, have bristle-shaped calyx segments and are tightly enclosed by four fused bracts forming an epicalyx. Comparative morphological and anatomical studies reveal a great diversity of epicalyx and calyx, often relevant to fruit dispersal. The present contribution deals with theScabiosa group of genera, the core of theScabioseae tribe. Most of its taxa develop a diaphragma from a meristem on the inside of the epicalyx. This diaphragma, together with the lower part of the epicalyx encloses the fruit proper, whereas the upper parts form a so-called “epi-diaphragma” (ed) and a ± hyaline corona. Differences of the epicalyx with respect to the size and position of the ed, elaboration of the corona, origin of pits (=foveoles) and other morphological and anatomical specializations can be demonstrated. Together with palynological and karyological data these new facts support an improved concept of relationships and systematics for the taxa studied:Scabiosa sect.Scabiosa and sect.Cyrtostemma are closely related and should be united to form the genusScabiosa s. str.;Pycnocomon can be maintained as an independent genus, sister toScabiosa sect.Trochocephalus which then has to be treated as a genus,Lomelosia. In contrast, the following genera have to be included inLomelosia:Tremastelma asLomelosia sect.Callistemma, andScabiosiopsis as part ofLomelosia sect.Lomelosia. Pseudoscabiosa deviates in so many features that it has to be excluded from the redefinedScabioseae s. str.