[Botany • 2025] Hoya biruensis (Apocynaceae: Asclepiadoideae) • A New night-blooming Species of Hoya from Borneo

Hoya biruensis Rodda & S.Rahayu,

in Rodda et Rahayu, 2025. 

DOI: doi.org/10.1002/njb.04787  

  facebook.com/MicheleRodda

illustration by Eunike Nugroho www.instagram.com/inikeke

Abstract

In the present paper, we describe Hoya biruensis, a new species from Borneo, Indonesia, West Kalimantan. It is characterised by a shrubby epiphytic pendulous habit, linear leaves, exceptionally long green peduncles produced at almost every node, and single, night-blooming flowers. We compare it to two morphologically similar species, H. spartioides and H. retrorsa, which are also endemic to Borneo.

Keywords: epiphyte, Hoya retrorsa, Hoya spartioides Indonesia, West Kalimantan

Hoya biruensis Rodda & S.Rahayu, sp. nov. 

illustration by Eunike Nugroho 

www.instagram.com/inikeke

 

Hoya biruensis Rodda & S.Rahayu, sp. nov.  

Michele Rodda and Sri Rahayu. 2025. A New night-blooming Species of Hoya (Apocynaceae: Asclepiadoideae) from Borneo. Nordic Journal of Botany. DOI: doi.org/10.1002/njb.04787 [17 April 2025]

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[Botany • 2021] Hoya batutikarensis • One New Species and A New Record of Hoya (Apocynaceae, Asclepiadoideae) from Sulawesi, Indonesia

Hoya batutikarensis   

in Ahmad, Zulfadli, Rahayu & Rodda, 2021. 

 DOI: 10.11646/phytotaxa.502.1.5

Abstract

One new species of Hoya from Indonesia, Hoya batutikarensis, is described and illustrated. It is similar to H. camphorifolia but it has unusual corona lobes, each lobe has a spreading process at base and an apical triangular process, while the corona of H. camphorifolia has simple navicular lobes. Hoya ischnopus, a species so far only known to occur in New Guinea, is newly recorded in Sulawesi, considerably extending its distribution area.

Keywords: Eudicots, Marsdenieae, Malesia, Sulawesi Tengah, taxonomy

Hoya batutikarensis

Roland Putra Pribadi Ahmad, Zulfadli Zulfadli, Sri Rahayu and Michele Rodda. 2021. One New Species and A New Record of Hoya (Apocynaceae, Asclepiadoideae) from Sulawesi, Indonesia. Phytotaxa. 502(1); 79–85. DOI: 10.11646/phytotaxa.502.1.5

[Botany • 2021] Ceropegia longicaudata (Apocynaceae, Asclepiadoideae) • Taxonomic Study of Ceropegia L. for The Flora of Laos: One New Species and One New Record from central Laos

Ceropegia longicaudata Phonep. & Rodda.

in Phonepaseth & Rodda, 2021. 

ດອກຈິນດາພູເຂົາຄວາຍ || taiwania.ntu.edu.tw 

Abstract

A newly discovered species from central Laos, Ceropegia longicaudata, is here described and illustrated. It is compared with the morphologically similar species Ceropegia cochleata Kidyoo. Ceropegia longicaudata displays clear differences in the leaf pubescence and venation, length of the corolla lobe tips, colour of corolla lobe, and shape of staminal corona lobes. Ceropegia cochleata is newly recorded for the Flora of Laos. A key to the now three species of Ceropegia in Laos is also provided.

Keyword: Ceropegia cochleata, Ceropegia laotica, Ceropegieae, Khammouan, new species, Phoukhaokhouay National Protected Area

Ceropegia longicaudata Phonep. & Rodda.
A. habit; B. open flower; C. longitudinal section of corolla; D. young flower bud; E. corona top view; F. corona side view; G. Pollinarium.

Drawn by P. Phonepaseuth from P005 (FOF).

Ceropegia longicaudata Phonep. & Rodda.
 A. habitat; B. habit; C. leaves adaxial and abaxial side; D. tuber; E. flower bud and open flower; F. longitudinal section of corolla; G. corona top view; H. corona from underneath; I. corona side view; J. pollinarium; K. dry flower (specimen).

Photos by P. Phonepaseuth from P005 (FOF)

Ceropegia longicaudata Phonep. & Rodda, sp. nov.

Diagnosis. Ceropegia longicaudata is similar to C. cochleata in having tuberous rootstock and linear lanceolate laminas. It can be separated by glabrous leaves without distinct nerves (vs. pubescent with distinct nerves in C. cochleata), longer corolla lobe tips (25–30 mm in C. longicaudata vs. 15–20 mm in C. cochleata), colour of corolla lobe completely bright green (vs. basally green with reddish brown apex), and staminal corona lobes distally with recurved diverging apices (vs. straight and converging).

Etymology. The specific epithet ‘longicaudata’ refers to long corolla lobes that characterize this species. 

Distribution. Only known from Phoukhaokhouay National Protected Area, in Laos. It is found at two locations, the type locality in Vientiane Province (Fig, 5), and from a locality 25–30 km eastwards, in Bolikhamxay Province, where it was photographed by Bertrand Laville in 2016 (theceropegiablog.wordpress.com/2016/02/22/anew-locality-for-Ceropegia-cochleata). 

Ecology and habitat. This species rooted in very thin soils over large sandstone boulders growing together with grasses. The plants were climbing over grasses in open areas partially exposed, at 270–300 m a.s.l. Flowering August–September.

 Vernacular name. ດອກຈິນດາພູເຂົາຄວາຍ ‘Dok Chinda Phoukhaokhouay’ [Phoukhaokhouay jewelry flower] (proposed here).

Phongphayboun Phonepaseth and Michele Rodda. 2021. Taxonomic Study of Ceropegia L. (Apocynaceae, Asclepiadoideae) for The Flora of Laos: One New Species and One New Record from central Laos. Taiwania. 66(1); 93-100. 

taiwania.ntu.edu.tw/abstract.php?type=abstract&id=1740

https://www.phakhaolao.la/en/news/taxonomic-study-ceropegia-lapocynaceae-asclepiadoideae-flora-laos-one-new-species-and-one-new

ພົງໄພບູນ ພອນປະເສີດ

[Botany • 2020] Heterostemma carnosum (Apocynaceae, Asclepiadoideae) • A New Species from Papua New Guinea

 Heterostemma carnosum Rodda

in Rodda, 2020. 

 taiwania.ntu.edu.tw 

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Abstract

The new species, Heterostemma carnosum is described, illustrated and compared with the similar species Heterostemma dalzellii. The two species differ in peduncle, pedicel and corolla size as well as in leaf shape.

Keywords: Ceropegieae, Crater Mountain, Papuasia

Fig. 1. Heterostemma carnosum Rodda.
 A. flowering branch; B. flower, view from above; C. flower, side view; D. pollinarium; E. follicle; F. seed.

(Based on the holotype, drawing by Loh Xiang Yun).

Heterostemma carnosum Rodda, sp. nov.

 Similar to H. dalzellii Hook., as both species have flowers with a rotate corolla, papillose inside, and a compressed-globose sessile corona. They are separated by the length of the peduncle (10–25 mm in H. carnosum, vs < 5 mm in H. dalzellii), pedicel (12–15 mm in H. carnosum vs < 7 mm in H. dalzellii and flower (corolla 2.5–3 cm diameter in H. carnosum vs < 1.5 cm in H. dalzellii).

Etymology. The specific epithet refers to the fleshy leaves and corolla (Latin carnosus = fleshy) that is an unusual feature in a genus that usually has species with thin leaves and corollas. 

Distribution and ecology. Heterostemma carnosum is only known from one specimen collected East of Haia Village, within Crater Mountain Wildlife Management Area, Papua New Guinea. Based on the label information, Heterostemma carnosum was collected in hill forest with some anthropogenic disturbance at the margins of an old garden. 

Michele Rodda. 2020. Heterostemma carnosum (Apocynaceae, Asclepiadoideae), A New Species from Papua New Guinea. Taiwania. 65(3); 326-328.  taiwania.ntu.edu.tw/abstract.php?type=abstract&id=1690  

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[Botany • 2020] Heterostemma cucphuongense (Apocynaceae, Asclepiadoideae) • A New Species from Vietnam

Heterostemma cucphuongense T.B.Tran & Rodda

in Tran, Han, Hai, ... et Rodda. 2020.   

DOI: 10.3897/phytokeys.148.50029

Photographs by N.Q. Dat, T.B. Tran, Thuong V.A.

Abstract

Heterostemma cucphuongense (Apocynaceae, Asclepiadoideae), a new species from Vietnam is described, illustrated and compared with the similar species Heterostemma succosum Kerr. Heterostemma cucphuongense differs from H. succosum by the morphology of the rachis of the inflorescence, the margins of the corolla lobes and the colour of the adaxial surface of the corolla.

Keywords: Ceropegieae, Cuc Phuong National Park

Figure 1. Heterostemma cucphuongense T.B.Tran & Rodda
A flowering branch B flower, view from above (adaxial) C flower, from underneath D corona, from above E ovary F pollinarium.

(Photographs by N.Q. Dat, T.B. Tran, Thuong V.A., photo edit by M. Rodda)

Heterostemma cucphuongense T.B.Tran & Rodda, sp. nov.

Diagnostic characters: This new species is similar to H. succosum Kerr, as both species have shortly pedunculate inflorescences, on which the flowers open in gradual succession (with generally a single flower open) and have relatively large rotate flowers (generally > 14 mm diam.). They are separated by the presence of a distinct rachis that develops in the inflorescence (which is absent in H. succosum); the margins of the corolla lobes are revolute (vs. flat in H. succosum), the pedicels are shorter (5–10 mm, vs. 15–30 mm in H. succosum) and by the colour of the adaxial surface of the corolla (red with white-yellow spots vs. yellow-orange with reddish-brown spots in H. succosum).

Etymology: The species is named after the type locality, Cuc Phuong National Park, in Ninh Binh Province, northern Vietnam.

Distribution and ecology: Heterostemma cucphuongense was only collected once, near one of the main trails in the Cuc Phuong National Park. It was found in primary evergreen forest on soils derived from degraded limestone. It was collected in flower in June.


The Bach Tran, Le Ngoc Han, Do Van Hai, Bui Hong Quang, Nguyen Thi Thanh Huong, Bui Thu Ha, Tran Van Hai and Michele Rodda. 2020. Heterostemma cucphuongense (Apocynaceae, Asclepiadoideae), A New Species from Vietnam.  PhytoKeys. 148: 119-124. DOI: 10.3897/phytokeys.148.50029

[Botany • 2020] Hoya sulawesiana & H. surisana • Two New Species of Hoya (Apocynaceae, Asclepiadoideae) from Sulawesi, Indonesia

Hoya sulawesiana S.Rahayu & Rodda

in Rodda & Sri Rahayu, 2020. 

 Taiwania. 65(2). taiwania.ntu.edu.tw

Abstract

We document the discovery of two new species of Hoya from Sulawesi, Indonesia, Hoya sulawesiana S.Rahayu & Rodda and Hoya surisana Rodda & S.Rahayu. Hoya sulawesiana is similar to Hoya isabelchanae Rodda & Simonsson in flower morphology because both species have very pubescent globose corolla but they can be separated based on leaf morphology and corolla indumentum type. Hoya surisana is very unusual because its flowers display a combination of large calyx lobes, a white, pubescent, campanulate corolla, and dark purple corona lobes so far not observed in any other species of the genus.

Keyword: Acanthostemma, Celebes, Cystidianthus, Hoya, Makalangkan Mountain, Mamuju, Marsdenieae

Fig. 1. Hoya sulawesiana S.Rahayu & Rodda.
 A, inflorescence; B, inflorescence, side view; C, flower, top view; D, flower, side view; E, corona, side view; F, corona, from underneath; G, leaves: right, from above; left, from underneath; H, pollinarium.

photos, A-G by Surisa Somadee; H by Michele Rodda.

Hoya sulawesiana S.Rahayu & Rodda, sp. nov. 

Similar to Hoya isabelchanae Rodda & Simonsson in inflorescence, corolla and corona morphology, but differing in lamina shape (orbicular-ovate (to elliptic), convex, to 7 cm long in H. isabelchanae vs. lanceolate or elliptic in H. sulawesiana 7–30 cm long), and in type of corolla inner surface pubescence (hairs straight and pointing outwards in H. isabelchanae vs. recurved towards the corona in H. sulawesiana).  

Distribution. Only known from South Sulawesi in Towuti and West Sulawesi in Mamuju at low elevation (100–300 m). 

Etymology. Hoya sulawesiana is named after the island of Sulawesi, where it is endemic.

Fig. 2. Hoya surisana Rodda & S.Rahayu.
 A, inflorescence; B, buds, almost ready to open; C, inflorescence back view, showing the large calices; D, leaves: right, from underneath; middle, from above; left, from above and immature;

photos, A-C by Surisa Somadee; D by Michele Rodda.

Fig. 3. Hoya surisana Rodda & S.Rahayu.
A, flower; B, flower, side view; C, calyx; D, E, corona, side view; F, corona, from underneath; G, follicle showing seeds within; H, pollinarium.

 photos, A-G by Surisa Somadee; H by Michele Rodda.

Hoya surisana Rodda & S.Rahayu, sp. nov.

 Similar to that of Hoya mappigera in corolla and corona shape and colour, but differing in number of flowers, size and shape of the calyx and corolla and in corolla pubescence. 

Distribution. only known from West Sulawesi, Makalangkan mountain, at about 500 m elev. 

Etymology. Hoya surisana is named after Surisa Somadee, Thai Hoya expert and grower.  

Michele Rodda and Sri Rahayu. 2020. Two New Species of Hoya (Apocynaceae, Asclepiadoideae) from Sulawesi, Indonesia. Taiwania. 65(2); 209-215.  taiwania.ntu.edu.tw/abstract.php?type=abstract&id=1675

[Botany • 2019] Hoya amicabilis (Apocynaceae: Asclepiadoideae) • A New Species from Java discovered on Facebook

Hoya amicabilis S.Rahayu & Rodda

in Rahayu & Rodda, 2019. 

  DOI: 10.1111/njb.02563

Abstract

A new species from Java, Hoya amicabilis S.Rahayu & Rodda is described and illustrated. It was first identified as a new species from pictures posted on social media in 2017. Hoya amicabilis is part of a small group of species that have an unusual shrubby habit, but it is the only one in that group with bright yellow campanulate flowers. Furthermore, Hoya amicabilis is a rather unusual species of Hoya since its staminal corona lobes are oblong, erect, while most species of Hoya have well‐developed generally spreading corona lobes, and its style head is umbonate, brightly coloured and extending above the anther appendages, while most species have a conical style head covered by anther appendages.

Keywords: Apocynaceae, Asclepiadoideae, Marsdenieae

Hoya amicabilis sp. nov. (a) fertile branch with just opened greenish-yellow flowers, (b) mature, side view, the corolla tube has turned green flushed orange and the corolla lobes turned orange, (c) corolla, top view, showing the stiff white hairs lining the tube.

 Photos: (a) S. Somadee, (b, c) M. Rodda. Based on M. Rodda & S. Somadee MR1820.

Hoya amicabilis S.Rahayu & Rodda sp. nov.

Etymology: Hoya amicabilis is named after social media (Latin amicabiliter interventus) that are a growing aid to scientists in discovering new species.

Sri Rahayu and Michele Rodda. 2019. Hoya amicabilis sp. nov. (Apocynaceae, Asclepiadoideae), from Java discovered on Facebook. Nordic Journal of Botany. 37(12)  DOI: 10.1111/njb.02563

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[Botany • 2017] Hoya fauziana ssp. angulata (Apocynaceae, Asclepiadoideae) • A New Subspecies from Borneo and Sumatra

Hoya fauziana ssp. angulata Rodda, A.L.Lamb, Gokusing & S.Rahayu

in Rodda, Lamb, et al., 2017. 
DOI: 10.3767/blumea.2018.63.02.10 

Abstract

A new Hoya subspecies from Borneo and Sumatra, Hoya fauziana ssp. angulata is described and illustrated. Both subspecies of Hoya fauziana have long lanceolate leaves, pubescent corollas and prominent ovoid corona lobes. They can be separated by the orientation of the pedicels (straight in H. fauziana ssp. fauziana and angled in H. fauziana ssp. angulata) and the type and position of pubescence of the corolla (tube and lobes pubescent with evident sericeous hairs in H. fauziana ssp. fauziana vs only tube finely pubescent in H. fauziana ssp. angulata).

Keywords: Asclepiadaceae; Hill Dipterocarp Forest; Indonesia; Kalabakan; Kalimantan; Malaysia; Sabah; Southeast Asia; epiphyte

Fig. 2 Hoya fauziana ssp. angulata Rodda,A.L.Lamb, Gokusing & S.Rahayu.
Living plant flowering in cultivation at Kipandi Park, Sabah, Malaysia.

— Photo by Steven Bosuang. 

Fig. 1 Hoya fauziana ssp. angulata Rodda,A.L.Lamb, Gokusing & S.Rahayu.
a. Corolla, top view; b. pedicel and calyx, side view; c. corona, from underneath; d. pedicel and calyx, top view; e. flower and pedicel, side view; f. pollinarium (Gokusing LG56/2017 (SAN)).

— Drawn by Xiang Yun Loh.

Hoya fauziana ssp. angulata Rodda, A.L.Lamb, Gokusing & S.Rahayu, subsp. nov. 

Distinguished from H. fauziana ssp. fauziana by the orientation of the flowers, all facing the same direction (vs perpendicular to the pedicel axis in H. fauziana ssp. fauziana) and by the fine pubescence of the corolla tube (vs long sericeous trichomes on the corolla tube and lobe in H. fauziana ssp. fauziana). 

 Type: L. Gokusing LG56/2017 (holo SAN), Malaysia, Sabah, Tawau, Kalabakan area, Mixed Hill Dipterocarp Forest, 16 May 2017.

M. Rodda, A.L. Lamb, L. Gokusing and S. Rahayu. 2017. Hoya fauziana ssp. angulata (Apocynaceae, Asclepiadoideae), A New Subspecies from Borneo and Sumatra. Blumea - Biodiversity, Evolution and Biogeography of Plants. DOI: 10.3767/blumea.2018.63.02.10

[Botany • 2019] Hoya of Sumatra (Apocynaceae, Asclepiadoideae), An Updated Checklist, Three New Species, and A New Subspecies

 Hoya sumatrana S.Rahayu & Rodda

in Rahayu & Rodda, 2019.

 DOI: 10.5852/ejt.2019.508

Abstract

The list of the species of Hoya R.Br. occurring on the Indonesian island of Sumatra is updated and the type citation is clarified. Sixteen taxa are added to the latest checklist. Hoya danumensis subsp. amarii S.Rahayu & Rodda subsp. nov., H. rigidifolia S.Rahayu & Rodda sp. nov., H. solokensis S.Rahayu & Rodda sp. nov., and H. sumatrana S.Rahayu & Rodda sp. nov. are newly described. Hoya parviflora Wight, H. parvifolia Schltr., and H. purpureofusca Hook. are lectotypified.

Keywords: Apocynaceae; Asclepiadaceae; Asclepiadoideae; Indonesia; Marsdenieae

Checklist of the genus Hoya of Sumatra

Class Magnoliopsida Brongn.

Subclass Asteridae Takht.

Order Gentianales Juss. ex Bercht. & J.Presl

Family Apocynaceae Juss.

Genus Hoya R.Br.

Hoya andalensis Kloppenb.

Hoya beccarii Rodda & Simonsson

Hoya brooksii Ridl.

Hoya campanulata Blume

Hoya caudata Hook.f.

Hoya coriacea Blume

Hoya coronaria Blume

Hoya danumensis subsp. amarii S.Rahayu & Rodda subsp. nov.

Etymology The new species is named after Amar Husein Sitompul, who collected the type specimen.

Notes Hoya danumensis subsp. amarii subsp. nov. can be separated from H. danumensis Rodda & Nyhuus (2009) subsp. danumensis because of the shape and size of the corolla that is shallowly campanulate, 20–23 mm in diameter and deeply campanulate, vs 25–35 mm in the latter; in the shape and size of the corona lobes that are ovate-oblong and 5.5–6 × 2.4–2.6 mm in H. danumensis subsp. danumensis vs ovate and 4.5–5 × 2.3–2.5 mm in the new subspecies.

Hoya deykeae T.Green

Hoya diversifolia Blume

Hoya elliptica Hook.f.

Hoya fauziana subsp. angulata Rodda, A.L.Lamb, Gokusing & S.Rahayu

Blumea 63: 144 (Rodda et al. 2018).  

Hoya finlaysonii Wight

Hoya forbesii King & Gamble

Hoya glabra Schltr.

Hoya imperialis Lindl.

Hoya kastbergii Kloppenb.

Hoya lacunosa Blume

Hoya lasiantha (Korth. ex Blume) Miq.

Hoya latifolia G.Don

Hoya mitrata Kerr nom. cons.

Hoya multiflora Blume

Hoya obtusifolia Wight

Hoya omlorii (Livsh. & Meve) L.Wanntorp & Meve

Hoya parviflora Wight

Hoya parvifolia Schltr.

Hoya purpurascens Teijsm. & Binn.

Hoya purpureofusca Hook.

Hoya revoluta Wight ex Hook.f.

Hoya rhodostele Ridl.

Fig. 2. Inflorescence, pollinarium, and leaf. C, E. Inflorescences. D, G. Pollinaria. F. Leaf.
C–D. Hoya solokensis S.Rahayu & Rodda sp. nov. (Fadly s.n. leg., BO).
E–G. Hoya rigidifolia S.Rahayu & Rodda sp. nov. (S. Rahayu 865 leg., BO).

Photos: Fadly (C), S. Rahayu (E–F), and M. Rodda (D, G).

Hoya rigidifolia S.Rahayu & Rodda sp. nov.

Etymology The new species is named for its rigid and stiff leaves.

Notes Hoya rigidifolia sp. nov. flowers only open for a single day. The flowers of H. finlaysonii are also open for a single day and have a similar flower morphology (rotate corolla, ovoid corona lobes of similar size). Both species are, however, easily separated based on leaf characters. Hoya finlaysonii has lanceolate to oblong leaves with pinnate venation, usually darker than the rest of the lamina; H. rigidifolia sp. nov. also has pinnate venation, but additionally it has two basal secondary veins running along the entire length of the lamina. The leaf venation of H. erythrina Rintz (1978) is similar to that of H. rigidifolia sp. nov.; however, both species can be separated based on flower charaters: H. erythrina has flowers with corolla > 15 mm in diameter when flattened, long-pubescent inside, and lasting > 2 days, while H. rigidifolia sp. nov. has flowers with corolla < 12 mm in diameter when flattened, glabrous inside, and lasting one day.

Hoya rintzii Rodda, Simonsson & S.Rahayu

Hoya rundumensis (T.Green) Rodda & Simonsson

Hoya sarcophylla Ridl.

Hoya scortechinii King & Gamble

Hoya sigillatis T.Green subsp. sigillatis

Hoya solokensis S.Rahayu & Rodda sp. nov.

Etymology The new species is named after the collection locality in Solok, Sumatra.

Notes Hoya solokensis sp. nov. is one of the few species of Hoya that exhibits a non-climbing habit but is instead an epiphytic shrub. It is morphologically similar to H. papaschonii Rodda (Rodda & Ercole 2014), a species only found in southern Thailand. Both species share a shrubby habit, short-lived peduncles, and flowers with a tubular corolla. However, H. papaschonii has the free part of the corolla lobes mostly held upright, while in H. solokensis sp. nov. the lobes are spreading; furthermore, the corona of H. papaschonii has both staminal and interstaminal elements while H. solokensis sp. nov. only has a staminal corona. Another species with a tubular corolla is H. telosmoides Omlor (1996) from Borneo, that is, however, a climber. The flowers of H. solokensis sp. nov. superficially resemble those of the Bornean H. hamiltoniorum A.L.Lamb, Gavrus, Emoi & Gokusing (Lamb et al. 2014) because both species have the free part of the corolla lobes spreading, however H. hamiltoniorum is a climber and its inner apex of the corona lobe is bifid, while the apex of the inner lobes of H. solokensis sp. nov. is entire.

Fig. 3. Hoya sumatrana S.Rahayu & Rodda sp. nov. 
A. Buds. B. Inflorescence, from underneath. C. Flower, from top. D. Corolla, from underneath, calyx and pedicel. E. Flower, side view. F. Corona, from underneath. G. Pedicel, calyx and ovaries. H. Pollinarium. Photos: M. Rodda.

Hoya sumatrana S.Rahayu & Rodda sp. nov

Etymology The new species is named after the Indonesian island of Sumatra.

Notes Hoya sumatrana sp. nov. is a new species in H. sect. Peltostemma Schlechter (1916: 14), characterized by upright corona lobes, long linear anther appendages extending well above the style-head and pollinaria with well developed caudicle wings. This section includes six species, two of which, H. soidaoensis Kidyoo (2013) and H. phuwuaensis Kidyoo (2016), have been recently published. Hoya sumatrana sp. nov. can be separated from all other members of this section because its flowers are much smaller; for example, the corolla of H. sumatrana sp. nov. is 7–9 mm in diameter, while the corolla of the second smallest species, H. flagellata Kerr (1940: tab. 3407), is > 10 mm in diameter, as well as the corona of Hoya sumatrana sp. nov. is 2.8–3.2 mm in diameter, while that of H. flagellata is > 4 mm in diameter. Another useful character to separate H. sumatrana sp. nov. from all other members of the section is the inner corona lobe process, that is bilobed in H. sumatrana sp. nov., while the other species have acute or rounded processes.

Hoya uncinata Teijsm. & Binn.

Hoya vitellinoides Bakh.f.

Hoya vitellina Blume

Hoya wrayi King & Gamble

Discussion: 

Since Rahayu & Wanntorp (2012), the Sumatran specimens identified as H. erythrostemma Kerr (1939) have been identified as H. rintzii, H. micrantha Hook.f. (Hooker 1883) has been re-determined as H. rundumensis, and H. verticillata was reported as H. parasitica Wall. ex Wight (1834). Nine species have been added to the inventory of Sumatran Hoya (Rahayu & Wanntorp 2012), all described based on Sumatran collections. These are H. andalensis, H. beccarii, H. brooksii, H. deykeae, H. omlorii, H. parvifolia, H. purpurascens, H. sarcophylla, and H. uncinata.

Hoya variifolia is considered a new synonym of H. parviflora. Two further species, H. glabra Schltr (Schlechter 1908) and H. kastbergii, are newly recorded.

The total count of taxa of Hoya known from Sumatra now stands at 43 and includes 41 species and two subspecies

Sri Rahayu and Michele Rodda. 2019. Hoya of Sumatra, An Updated Checklist, Three New Species, and A New Subspecies. European Journal of Taxonomy. 508; 1–23. DOI: 10.5852/ejt.2019.508

[Botany • 2019] Hoya pulchra (Apocynaceae) • A New Species from southern Philippines [Hoya of the Philippines part II]

Hoya pulchra Aurigue & Cabactulan

in Cabactulan, Aurigue, Pimentel, De Leon, Sahagun & Rodda, 2019.  

photo: facebook.com/MiguelDeLeon75033149

A new species, Hoya pulchra Aurigue & Cabactulan (Apocynaceae), is described and illustrated. It is compared with the similar H. waymaniae, endemic to Borneo, from which it differs in lamina shape (lanceolate with a flat edge vs. elliptic-ovate with undulate edge) and the absence of bilobed apex in the outer corona lobe apex vs. a short raised bilobed apex.

Derek D. Cabactulan, Fernando Aurigue, Reynold Pimentel, Miguel D. De Leon, Jorge Sahagun and Michele Rodda. 2019. Hoya of the Philippines, part II: Hoya pulchra (Apocynaceae), A New Species from southern Philippines. Ann. Bot. Fennici. 56: 49–53.  

facebook.com/MiguelDeLeon75033149/posts/1078317419017575

[Botany • 2017] Hoya migueldavidii • A New Species (Apocynaceae, Asclepiadoideae) from Northern Mindanao, Philippines [Hoya of the Philippines part I]

Hoya migueldavidii  Cabactulan, Rodda & Pimentel

DOI: 10.3897/phytokeys.80.12872 

Abstract

A new species of Hoya R.Br. from Mindanao (Philippines), Hoya migueldavidii Cabactulan, Rodda & Pimentel, is described and illustrated. It is a member of Hoya section Acanthostemma (Blume) Kloppenb. that is particularly speciose in the Philippines. It is compared with the similar Hoya loheri Kloppenb, also endemic of the Philippines, from which it differs in indumentum of the vegetative parts (pubescent vs. glabrous), the shape of the corolla (almost spherical vs. partly flattened) and the type of gynostegium (not stipitate vs. stipitate)

Keywords: Acanthostemma, Marsdenieae, waxflower

Figure 1: Hoya migueldavidii photographed from R. Pimentel s.n. (CMUH) prior to pressing
A A single flower, front view B, C Corolla, side view D Corolla, with removed corona E Revolute margins of the corolla lobes F Corona, from underneath G, H Pedicel, calyx and ovary I Pollinarium

(Photographs by M.D de Leon)
DOI: 10.3897/phytokeys.80.12872

Figure 2: Hoya migueldavidii photographed from R. Pimentel s.n. (CMUH) prior to pressing
A Inflorescence B Branch C, D leaf (C adaxial surface D abaxial surface). (Photographs by M.D de Leon).

Figure 1: Hoya migueldavidii photographed from R. Pimentel s.n. (CMUH) prior to pressing A A single flower, front view B, C Corolla, side view D Corolla, with removed corona E Revolute margins of the corolla lobes F Corona, from underneath G, H Pedicel, calyx and ovary I Pollinarium (Photographs by M.D de Leon)

Figure 2: Hoya migueldavidii photographed from R. Pimentel s.n. (CMUH) prior to pressing A Inflorescence B Branch C, D leaf (C adaxial surface D abaxial surface). (Photographs by M.D de Leon). 

DOI: 10.3897/phytokeys.80.12872

Hoya migueldavidii Cabactulan, Rodda & Pimentel, sp. nov.

 Diagnosis: Among Philippine Hoya species similar to Hoya loheri in inflorescence type (positively geotropic, convex) but separated because Hoya loheri has a flattened, turban-shaped corolla (vs. almost round in Hoya migueldavidii) and leaves and stems are entirely glabrous (vs. pubescent in Hoya migueldavidii)

Figure 3. Hoya loheri photographed from Rodda M MR748 (SING) prior to pressing A Leafy branch and inflorescence B Inflorescence. (Photographs by M. Rodda) 

Type: Philippines, Mindanao, Bukidnon, Mount Kitanglad, 11 Aug 2016, R. Pimentel s.n. (CMUH, holotype, sheet number CMUH 827; SING, isotype).

Etymology: Hoya migueldavidii is named after Dr. Miguel David de Leon, viteoretina surgeon and plant and wildlife conservationist.

Distribution and ecology: This new species was only once collected in Mindanao Island, Philippines but the full distribution is still unknown. It is an epiphytic climber, growing at about 1000 m in disturbed primary broad leaf forest in full sun to part shade.

Derek D. Cabactulan, Michele Rodda and Reynold Pimentel. 2017. Hoya of the Philippines part I. Hoya migueldavidii (Apocynaceae, Asclepiadoideae), A New Species from Northern Mindanao, Philippines. PhytoKeys. 80; 105-112.    DOI: 10.3897/phytokeys.80.12872

 

[Botany • 2016] Hoya isabelchanae • A New, Showy Species of Hoya R.Br. (Apocynaceae, Asclepiadoideae) with Pomegranate Red Flowers from Sulawesi, Indonesia

Hoya isabelchanae 

 Rodda & Simonsson 

DOI:  10.3897/phytokeys.68.8803

Abstract

A new species of Hoya R.Br. from Sulawesi (Indonesia), Hoya isabelchanae Rodda & Simonsson, is described and illustrated. It is one of the largest flowered species in Hoya section Acanthostemma (Blume) Kloppenb. Its flowers are of comparable size to those of Hoya benchaii Gavrus et al., Hoya kloppenburgii T.Green, Hoya rundumensis (T.Green) Rodda & Simonsson and Hoya sigillatis T.Green ssp. sigillatis, all from Borneo. Among Sulawesi species it is compared with the vegetatively similar Hoya brevialata Kleijn & van Donkelaar and Hoya pallilimba Kleijn & van Donkelaar.

Keywords: Borneo, Cultivation, Gunung Boliohutu, Malesia, Marsdenieae

Hoya isabelchanae Rodda & Simonsson, sp. nov.

Diagnosis: Among Sulawesi Hoya species similar to H. brevialata and H. pallilimba in habit (prostrate and pendant epiphyte), lamina shape (convex round to elliptic) and inflorescence type (positively geotropic, convex) but separated because both H. brevialata and H. pallilimba have smaller flowers (c. 5 vs. 8–10 mm in diameter in H. isabelchanae) with a finely pubescent corolla (vs. setose corolla in H. isabelchanae).

Type: Indonesia, Sulawesi, Gorontalo, Gunung Boliohutu, 400 m, 23 Apr 2002, S.M. Scott 02-116, grown on at the Royal Botanic Garden Edinburgh (Acc no. 20021229), Sep 2012, C.E. Berthold 0013 (holotype: E; isotype: SING)

Etymology: Hoya isabelchanae is named after Isabel Claire Chan Yuen Ching, late daughter of Elisabeth Chan, Singaporean patron of botanical research and a gardener with an interest in Hoya.

Distribution and ecology: Hoya isabelchanae is only known from the base of Gunung Boliohutu, Sulawesi, where it was collected as a sterile cutting in 2002 and brought into cultivation at the Royal Botanic Garden Edinburgh where it regularly blooms in a heated greenhouse from May to October. The species was collected in primary forest and it was growing in shaded but exposed area on a decaying tree 12 m tall. A further collection is widely available in cultivation under Gerard Paul Shirley number GPS10161 and 7-35 http://www.paulshirleysucculents.nl/shop_hoyas.htm [accessed on 24 June 2016]. This accession is apparently also from Sulawesi but no further collection information is available.

 Michele Rodda and Nadhanielle Simonsson Juhonewe. 2016. Hoya isabelchanae Rodda & Simonsson, A New, Showy Species of Hoya R.Br. (Apocynaceae, Asclepiadoideae) with Pomegranate Red Flowers from Sulawesi, Indonesia. PhytoKeys. 68: 45-50. DOI:  10.3897/phytokeys.68.8803