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| Drosera margaritacea T.Krueger & A.Fleischm. in Krueger & Fleischmann, 2021. |
Abstract
A new annual species of Drosera section Arachnopus, Drosera margaritacea, from the western Kimberley region (Western Australia) is described and illustrated, including detailed comparisons with the morphologically most similar species, D. finlaysoniana. The latter name is lectotypified here. The global range of D. finlaysoniana is provided, including a doubtful first record for Thailand, while the species, in contrast with statements made in some published references, does not occur in India, Laos, Cambodia and the Philippines. Additionally, the first record from Indonesia of the frequently misidentified D. aquatica is reported.
Keywords: Eudicots, carnivorous plants, Indochina, lectotypification, non-core Caryophyllales, Nepenthales, taxonomy
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| Drosera margaritacea T.Krueger & A.Fleischm. A. habit. B. stem and leaf base. C. transection of lamina (left) and petiole (right). D. stalked milky-white glands from petiole adaxial surface. E. yellow-headed capitate trichomes (two on left) and biseriate doubletipped trichome (right) from leaf abaxial surface (identical indumentum present on stem, peduncle, pedicels and calyx). F. peduncle, detail of indumentum. G. pedicel, detail of indumentum. H. bracts, left: from lower part of the rhachis, right: from upper part. I. sepal. J. petal. K. gynoecium and anthers. L. anthers, left: lateral view, right: dorsal view. M. seed. All from the type collection (T. Krueger 7), B–E from alcohol preserved leaves, the rest from herbarium material. Drawing by A. Fleischmann. |
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| Drosera margaritacea T.Krueger & A.Fleischm. A. habit; note the very tall, many-flowered inflorescences. B. stem, with peduncle and leaf bases, showing the stalked milky-white glands on the adaxial petiole surfaces. C. flower. D. close-up of petiole covered with stalked milky-white glands, lateral view. E. close-up of stamens; note the rounded yellow connective tips around which the thecae protrude. F. inflorescence. G. close-up of petiole covered with stalked milky-white glands, adaxial view. All photographs taken at the type locality on 18 July 2020 by T. Krueger. |
Drosera margaritacea T.Krueger & A.Fleischm., sp. nov.
Diagnosis:—Drosera margaritacea is morphologically similar to Drosera finlaysoniana Wall. ex Arn. in Hook. from
which it differs (contrasting characters in parentheses) by its petiolate leaves, borne on a 1.5–3.5 mm long petiole
(leaves sessile), petiole covered with 20–50 stalked secretive glands 0.10–0.40 mm long with a multicellular stalk and translucent milky white, hemispherical to depressed ovoid gland head 0.10–0.30 mm in diameter that remains
present even in dried material (petiole absent), stem, leaves, peduncle, pedicels and sepals covered with 0.05–0.30
mm long stalked capitate trichomes with uniseriate stalk and yellow, spherical, non-secretory gland head ca. 0.05
mm in diameter (stem, abaxial leaf surface, peduncle, pedicels and sepals covered with 0.1–0.3 mm long secretory
capitate trichomes with uniseriate stalk and flattened gland head secreting a translucent mucilage droplet 0.1–0.2 mm
in diameter), T-or Y-shaped trichomes absent (adaxial leaf bases and margins covered with 0.05–0.40 mm long T-or
Y-shaped trichomes), inflorescence (20–)30–55(–65) cm long, with at least 30–50 flowers, its peduncle held upright,
± parallel to stem and much exceeding the carnivorous leaves (inflorescence (3–)6–18(–26) cm long, (2–)6–20(–26)-
flowered, peduncle usually horizontal [this character is typically very obvious in live specimens, but sometimes not
easily discerned in pressed herbarium material], shorter than or at most equalling the leaves in length), flowers 18–24
mm in diameter (7–14(–20) mm in diameter), stamen connective longer than filament, shorter than thecae and with
rounded yellow tip ca. 0.2–0.4 mm in diameter (stamen connective usually much shorter than filament, as long as the
thecae, lacking a rounded yellow tip).
Etymology:—The species’ epithet (from Latin margaritaceus = pearly, pearl-bearing) refers to the indumentum
of unique, stalked secretive glands with translucent milky white, hemispherical to depressed ovoid (pearl-like) gland
heads, as well as to the characteristic swollen, roundish (pearl-like) apical dilatation of the anther connective.
Thilo Krueger and Andreas Fleischmann. 2021. A New Species of Drosera Section Arachnopus (Droseraceae) from the western Kimberley, Australia, and Amendments to the Range and Circumscription of Drosera finlaysoniana. Phytotaxa. 501(1); 56–84. DOI: 10.11646/phytotaxa.501.1.2
