Hydnora arabica (Aristolochiaceae), a New Species from the Arabian Peninsula and a Key to Hydnora

The plant parasite Hydnora arabica (Aristolochiaceae) is described from the Arabian Peninsula. This species was previously identified as Hydnora africana in Oman. It can be separated from other Hydnora taxa primarily by its terete rhizome, red to orange inner perianth tube color, and tepal lobe margins entirely covered with dense strigose setae. In Oman, Hydnora arabica is known to parasitize two leguminous trees: Acacia tortilis and the introduced Pithocellobium dulce, but may parasitize additional Fabaceae. At least eleven synonyms or subspecific varieties of H. abyssinica are described in the literature, all from east or southern Africa. These synonyms are discussed in light of new observations of morphology including tepal margin ornamentation. A new key for Hydnora is proposed

A New Species of Diploid Quillwort (Isoetes, Isoetaceae, Lycophyta) from Lebanon

A new species, Isoetes libanotica Musselman, Bolin & B. D. Bray (Isoetaceae, Lycophyta), is described from Akkar District of northern Lebanon. It is a seasonal terrestrial species of basaltic soils, diploid (2n = 22), with complete velum coverage. Megaspore diameter ranges from 338 to 477 mu m with remote, low tuberculate ornamentation and a low to obsolete equatorial girdle; microspore length ranges from 25 to 30 mu m, with echinate ornamentation. At the type locality of I. libanotica, two other Isoetes L. species occur sympatrically. These superficially similar Isoetes species can be differentiated from I. libanotica using megaspore characters; I. duriei Bory has larger alveolate megaspores and I. olympica A. Braun has a prominent equatorial girdle

A New Species of Diploid Quillwort (Isoetes, Isoetaceae, Lycophyta) from Lebanon

A new species, Isoetes libanotica Musselman, Bolin & B. D. Bray (Isoetaceae, Lycophyta), is described from Akkar District of northern Lebanon. It is a seasonal terrestrial species of basaltic soils, diploid (2n = 22), with complete velum coverage. Megaspore diameter ranges from 338 to 477 mu m with remote, low tuberculate ornamentation and a low to obsolete equatorial girdle; microspore length ranges from 25 to 30 mu m, with echinate ornamentation. At the type locality of I. libanotica, two other Isoetes L. species occur sympatrically. These superficially similar Isoetes species can be differentiated from I. libanotica using megaspore characters; I. duriei Bory has larger alveolate megaspores and I. olympica A. Braun has a prominent equatorial girdle

Structural Attributes of the Hypogeous Holoparasite Hydnora Triceps Drège & Meyer (Hydnoraceae)

The morphology of the hypogeous root holoparasite Hydnora triceps is highly reduced, and as with many holoparasites, the vegetative body is difficult to interpret. The vegetative body of H. triceps has been historically considered a pilot root studded with lateral appendages known as haustorial roots. We found the vegetative body of H. triceps to consist of a rhizome with a thickened root-cap-like structure that covered a vegetative shoot apical meristem. From the apical meristem, procambial strands originated and developed into endarch collateral vascular bundles arranged radially around a pith without an interfascicular cambium. Xylem vessels had scalariform pitting and simple perforation plates. A continuous periderm without root hairs was observed. Increase in girth was attributed to cork and fascicular cambia. Haustorial roots or bumps on the surface of the vegetative body were exogenous, contained meristems and were the origins of vegetative branching, budding, and haustoria. The haustoria of H. triceps were cylindrical and penetrated the host root stele. Phloem and xylem elements were observed within the endophyte, and direct xylem to host-xylem contacts were observed. The arrangement of vascular tissues and xylem anatomy of H. triceps are likely plesiomorphic features in light of Hydnoraceae\u27s placement in the Piperales

The Genus \u3ci\u3eIsoetes\u3c/i\u3e L. (Isoetaceae, Lycophyta) in South-Western Asia

Quillworts or Çim Eğreltisi, species of the genus Isoetes L. in Turkey and the Levant, are poorly studied despite extensive floristic studies in the region. The Flora of Turkey lists 4 taxa: Isoetes olympica A.Braun (2n = 22), I. histrix Bory var. histrix (2n = 20), I. subinermis (Bory) Cesca & Peruzzi [=I. histrix Bory var. subinermis Durieu (2n = 22)] and I. duriei Bory (2n = ca. 121). An additional species, I. anatolica Prada & Rolleri, was described in 2005 from Bolu province, and we report the first count for this species, 2n = 22. In Syria and Lebanon 2 species are known: I. olympica from a site in Syria and a known but undescribed plant from Akkar province (Lebanon) and adjacent Syria (2n = 22, first count). A preliminary molecular phylogeny for these species is presented; their distribution and cytology are discussed. The taxonomy and nomenclature of the I. histrix and I. duriei groups need considerable further study. The first hybrids for the region are documented