1. Family: Orobanchaceae Vent.
    1. Genus: Aeginetia L.
      1. Aeginetia flava J.Parn.

        This species is accepted, and its native range is Thailand.

    [KBu]

    Parnell, J. 2012. Kew Bulletin 67: 81. https://doi.org/10.1007/s12225-012-9337-9

    Habit
    Parasitic perennial herb
    Stem
    Stems all flowering, solitary or branched near the base, 15 – 20 cm tall; reddish-yellow; with 2 opposite narrowly triangular, scale-like leaves 10 mm by 2 mm towards the base
    Flowers
    Flowers solitary; buds ellipsoid
    Calyx
    Calyx 2.5 – 4 cm long, spathulate, the tip erect to recurved; whitish yellow at the base grading into pale pinkish at the tip; glossy
    Corolla
    Corolla 3.5 – 5.5 cm long; 2.5 – 4 cm of tube exserted beyond calyx, exserted portion of tube down-curved or ± straight, somewhat dilated on emergence from calyx, bright yellow; lower portion of concealed part of tube strongly flexed, ± geniculate, forming a narrow throat above the ovary, the throat somewhat dilated in its mid-portion; lobes c. 0.5 – 1 cm long, widely spreading, slightly recurved at tips, markedly but shallowly and irregularly dentate with the teeth c. 0.75 mm; bright yellow; glossy externally
    Stamens
    Stamens included, massed together, attached ± at point of inflection of corolla tube, point of attachment hairless; anthers with 1 cell perfect, dehiscence by ± apical pore-like slits; upper stamens spurred and gibbous; lower gibbous but only minutely spurred; spur with a terminal conical projection at the tip; filaments of upper stamens distinctly papillate near anther; filaments of lower stamens ± smooth; anthers hairless
    Style
    Style yellow, curved; reaching nearly to top of corolla tube; stigma yellow, included; peltate
    Fruits
    Capsule c. 1.6 cm × 1 cm, ovoid, splitting near maturity; seeds ovoid 0.3 × 0.2 mm; finely reticulate
    Distribution
    Thailand: Chanthaburi province. Known only from Khao Soi Dao Nuea and Khao Soi Dao Tai.
    Ecology
    In rainforest; alt. 1,400 – 1,540 m. The dominant upper storey tree probably being Quercus semiserrataRoxb., with Pinangasylvestris (Lour.) Hodel very common in the mid-storey. An unidentified Strobilanthes species dominates the ground layer, and the several Aeginetia flava plants checked were all attached to it via their root-system, and seem to be parasitising that species.
    Conservation
    The species was first found in 2008 and there is no information about its abundance or distribution beyond Khao Soi Dao Wildlife Sanctuary, where it is locally common at higher altitudes. The relative inaccessibility of these higher altitudes (there are few roads in the wildlife sanctuary, and none go higher than 400 m altitude) may assist in the species’ protection. Therefore as no significant threat is known, using the IUCN criteria (2001) I assess this plant as Vulnerable (VU D2).
    Note
    The specific epithet refers to the colour of the flowers and plant. The spathaceous calyx and growth habit clearly places this species in Aeginetia, and within that genus it appears most morphologically similar to A. indica, which is, as remarked above, morphologically variable. However, A. flava differs from all known A. indica in the possession of relatively conspicuous scale leaves near the base of the flowering stem, its occasionally branching habit, and most obviously in its bright yellow corolla with broadly spreading, dentate corolla lobes (those of A. indica are usually only slightly spreading or not spreading at all and are not dentate); it also has a somewhat smaller capsule and seeds whose surface reticulations are smaller (c. 45 μm in diam. in A. flava as opposed to c. 70 μm in A. indica) (Fig. 3). The seeds are clearly of the so-called ‘deeply reticulate type’ common in the Orobanchaceae of Musselman & Mann (1976), having a testa with an outer layer of enlarged polygonal cells whose outer walls break down as the seed matures leaving a series of walls enclosing pits of distinct size. The outer walls of the testa were exceptionally fragile after preparation for SEM, thus some rupturing occurred during normal specimen handling. Although yellow flowered species occur in certain genera of the Orobanchaceae e.g. (Cistanche and Conopholis) they were unknown in Aeginetia until the discovery of this species. Extraction of DNA for molecular analysis has so far proven unsuccessful.

    Distribution

    Native to:

    Thailand

    Aeginetia flava J.Parn. appears in other Kew resources:

    First published in Kew Bull. 67: 81 (2012)

    Literature

    Kew Bulletin
    • Parnell, J. (2008). Orobanchaceae. In: T. Santisuk, K. Larsen, I. Nielsen, K. Chayamarit, C. Phengkhlai, H. Pedersen, J. Parnell, D. Middleton, M. Newman, D. A. Simpson, P. C. van Welzen, S. Hul & M. Kato, Flora of Thailand 9 (2): 142 – 147. The Forest Herbarium, National Park, Wildlife and Conservation Department, Bangkok.Google Scholar
    • IUCN (2001). IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland, Switzerland & Cambridge, UK.Google Scholar
    • Parnell, J. (2001). A revision of Orobanchaceae in Thailand. Thai Forest Bull., Bot. 29: 72 – 80.Google Scholar
    • Musselman, L. J. & Mann, W. F. (1976). A survey of surface characteristics of seeds of Scrophulariaceae and Orobanchaceae using scanning electron microscopy. Phytomorphology 26: 370 – 378.Google Scholar
    • Beck-Managetta, G. (1956). Orobanchaceae. In: A. Engler, Pflanzenreich 4: 261. H. Buchna & Sohn, Neudruck. (Photographic reprint of the original volume issued in 1930).Google Scholar

    Sources

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Bulletin
    Kew Bulletin
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0