Rhodocodon jackyi Knirsch, Mart.
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publication ID |
https://doi.org/ 10.11646/phytotaxa.253.3.3 |
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persistent identifier |
https://treatment.plazi.org/id/038187D4-FF94-FF88-4ED4-05EDFAC395EC |
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treatment provided by |
Felipe |
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scientific name |
Rhodocodon jackyi Knirsch, Mart. |
| status |
sp. nov. |
Rhodocodon jackyi Knirsch, Mart. View in CoL -Azorín & Wetschnig, sp. nov. ( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )
It resembles R. urgineoides in its general appearance, however the new species shows a different vegetative habit (not epiphytic), has a thicker inflorescence peduncle, longer floral pedicels, larger flowers and a rosette of deciduous leaves that are usually larger at anthesis.
Type:— MADAGASCAR. Province Toliara, region Anosy: near the village Vatambe , 330 m elevation, W. Knirsch, A. Sieder & J. Andriantiana 6620, ex hort. in AUSTRIA, Steiermark, Graz, Botanical Garden of the Institute of Plant Sciences of the University of Graz on 30th April 2014, W. Knirsch, corresponding to WW04669 (holotype GZU-000324829!; isotypes P!, PBZT!) .
Deciduous bulbous plant, 35 ‒ 70 cm high. Bulb ovoid, 3 ‒ 5 × 2.5 ‒ 4 cm, splitting and forming clumps; roots white, branched. Leaves in a spiral rosette, 3 ‒ 8 per bulb, ensiform with acute tip, 30 ‒ 45 × 1.8 ‒ 3.5 cm, synanthous, deciduous, green, glabrous, smooth, with a discrete hyaline margin and a slight keel on the abaxial side. Inflorescence a secund raceme, curved; peduncle 30–50 cm long, ca. 5 mm in diameter, glabrous, smooth; raceme 12 ‒ 35 cm long with 30 ‒ 56 flowers; pedicels 12 ‒ 22 mm long, white, pink-purplish or greenish. Bracts lanceolate, acute, membranous, subpetiolate, the lowermost 1 ‒ 3 mm long, with an acute spur 1 ‒ 4 mm long, both bract and spur diminishing in size to the apex of the inflorescence; bracteoles present. Flowers white, nodding, with a discrete green to red stripe along the perigone lobes. Perigone campanulate and slightly contracted at the apex, ca. 7.6 ‒ 9 × 5 ‒ 6.1 mm, connate for most of its length, with acute, spreading free lobes ca. 1.2 mm long. Stamens 6; filaments strap-shaped, shortly adnate to the perigone tube and arising from its basal portion; free portion of filaments ca. 0.8 × 0.4 mm, incurved and approaching the base of the style; anthers (just opened) 1.9 × 0.9 mm, yellow - green, dehiscing by longitudinal slits along their upper half. Ovary oblong, ca. 3 × 2.1 mm, with 15 ‒ 17 ovules per locule; style ca. 2.5 mm long, narrowly conical, ca. 0.8 mm wide at the base and tapering to the apex (0.4 mm), inconspicuously trigonous in section; stigma punctiform. Capsule trigonous, 9 ‒ 10 × 5 ‒ 8 mm. Seeds 15 ‒ 17 per locule, flattened, fusiform, sometimes slightly bent, L-H-W: 4–5 × 1.5–2 × 0.5–1.2 mm, light brown, with a weak gloss, lacking a distinct raphe.
Eponymy:—The specific epithet “ jackyi ” honours Jacky Lucien Andriantiana (Parc Botanique et Zoologique de Tsimbazaza), who collected this species for the first time in 2011 as Rhodocodon urgineoides , and who organised and helped us during several collecting trips in Madagascar.
Phenology: — Rhodocodon jackyi flowers and fruits between October and January in cultivation in Austria. When collected in January 2014, only an old infructescence lacking flowers or fruits was found ( Fig. 1 View FIGURE 1 ). Further research is needed to reveal the phenology of this species in the wild.
Habitat:— Rhodocodon jackyi grows on granitic, exposed plateaus in patches of Coleochloa setifera ( Ridley 1883: 337) Gilly (1943: 14) at an elevation of 300–350 m near Vatambe in association with species of Habenaria Willdenow (1805: 5) and Cynorkis Thouars (1809: 317) ( Fig. 1 View FIGURE 1 ). The vegetation type is a transition between humid forest and western dry grassland. This region has a tropical wet climate. The mean annual temperature is 23 ° C and total annual precipitation average is 1680 mm.
Distribution:— Madagascar. Province Toliara: region Anosy, district Tôlanaro.
Taxonomic relationships: — Rhodocodon jackyi is characterised by the deciduous synanthous leaves that are usually large and spirally arranged in a rosette ( Fig. 1 View FIGURE 1 ); the many flowered, lax, secund raceme; the long pedicels; and the white, campanulate, nodding flowers ( Fig. 2 View FIGURE 2 , Table 1). Rhodocodon urgineoides resembles R. jackyi , but the former differs by the evergreen smaller leaves that show a somewhat distichous arrangement, and the less flowered raceme with shorter pedicels ( Table 1). Both species also show clear differences in habitat. Whilst R. urgineoides occurs in humid forest, and grows mostly epiphytic (the bulbs grow in moss on trees or large rocks), R. jackyi is terrestrial and is found in patches of Coleochloa setifera ( Cyperaceae ) on granitic, exposed plateaus ( Table 1, Fig. 1 View FIGURE 1 ). Furthermore, R. urgineoides is the widest spread Rhodocodon species in Madagascar, occurring along the humid eastern zone of the island and spreading into the western parts along the Sambirano valley, whereas R. jackyi is only known to us from the surroundings of Vatambe ( Table 1). Our preliminary phylogenetic results based on cpDNA data (not shown) place R. urgineoides and R. jackyi in two different clades, a fact also supporting the description of the new species.
| W |
Naturhistorisches Museum Wien |
| A |
Harvard University - Arnold Arboretum |
| J |
University of the Witwatersrand |
| P |
Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants |
| PBZT |
Parc Botanique et Zoologique de Tsimbazaza |
| C |
University of Copenhagen |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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