Research Article |
Corresponding author: Annalee S. Hadsall ( ashadsall@up.edu.ph ) Academic editor: Clifford Morden
© 2016 Annalee S. Hadsall, Michelle D.R. Alejado, Ariel R. Larona, Ivy Amor F. Lambio.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Hadsall AS, Alejado MDR, Larona AR, Lambio IAF (2016) Strongylodon juangonzalezii, a remarkable new species of Strongylodon (Fabaceae) from Mulanay, Quezon Province, Philippines. PhytoKeys 73: 1-12. https://doi.org/10.3897/phytokeys.73.10055
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A new species, Strongylodon juangonzalezii Hadsall, Alejado & Cajano, collected from Buenavista Protected Landscape, Mulanay, Quezon, is hereby described. The new species is remarkable for its plagiotropic dense inflorescence made up of 27–31 flowers per cluster in a lateral branch. Flowers are lilac when young, then gradually turn blue when mature. A comparison of the morphology of S. juangonzalezii and related species of Strongylodon in the Philippines is provided. Detailed illustration based on the holotype and photos from its natural habitat are also included. With this new species, the Philippines now harbors eight endemic species of Strongylodon. A key to distinguish the species is provided.
Mulanay, Fabaceae , Quezon, Philippines, Strongylodon
Strongylodon (Fabaceae – Papilionoideae – Erythrininae) was described as a genus in 1836 by Julius Rudolph Theodor Vogel. Its distribution includes Madagascar and Reunion to Sri Lanka, India, Australia, and northward to the islands of the Pacific (Polhill 1912,
The genus derived its name from the Greek words “strongylos” meaning ‘round’ and “odontos” means ‘toothlike’, referring to the rounded teeth of the calyx. It is also known to exhibit inflorescences in drooping racemes whose color ranges from purplish blue to bluish green to red or orange red (
Four sections comprise the genus, namely: Strongylodon, Archboldianus, Macrobotrys, and Craveniae (
In February 2015, a collaborative field study between
Strongylodon juangonzalezii a habens inflorescentiae racemi spicae densi plagiotropici, lilacinus cum iuvenibus et caerulei cum maturibus, et cum brachyblastae cylindricae et magis quam tres flores in congeners differt.
Strongylodon juangonzalezii differs from other species of Strongylodon in having dense plagiotropic raceme inflorescence with flowers that are lilac when young and turn blue when mature, and with brachyblasts that are cylindrical and more than 3 flowered.
Strongylodon juangonzalezii sp. nov. A growth habit, inset shows the distinct middle and lateral stipules B portion of a flowering branch C Detached flower D dissected flower E calyx F androecium and anther G intact pod H pod opened to show the seeds I seeds, front and side view J brachyblast.
PHILIPPINES. Luzon, Island, Quezon Province, Municipality of Mulanay, Barangay Buenavista, Sitio Maglayaw, Buenavista Protected Landscape (
Woody vine reaching the top of the canopy. Mature branches glabrous with lenticels. Leaves 3-foliolate, each 3-nerved, adaxial and abaxial surfaces dark green, margin entire, apex acute, base rounded; lateral leaflets broadly-ovate, oblique, 9 cm long, 6.2 cm wide; terminal leaflet ovate-elliptic, 10.4 cm long, 6.0 cm wide; petiole green, glabrous, base swollen, 12.4–12.6 cm long; rachis green, glabrous, 2.8–2.9 cm long; petiolule green, glabrous, base swollen, 1.2 cm long; stipules three, basifixed, axillary, middle one cylindrical and persistent, lateral ones caducous, leaving conspicuous scars. Inflorescence a dense plagiotropic raceme, up to 12.0 cm long, branches alternating on the main axes; peduncle 2–8 cm, shorter than flowering axis; lateral flowering branches 13.0–27.0 cm long, occurring in pairs, arising from node; pedicel 1.7–1.9 cm long; brachyblasts warty, more than 3-flowered, 5 mm long and 1 mm wide. Flowers 7–9 in a cluster, arranged alternately, 27–31 flowers in a cluster in a lateral branch, with outer flowers opening first; young flowers lilac; calyx lilac, cup-shaped, glabrous, entire; standard petal lanceolate, 2.5–2.6 cm long, 1.3–1.4 cm wide, basal portion ridged, both surfaces of standard petal turns light blue when mature; wings oval 1.2–1.4 cm long, 0.6–0.7 cm wide, slightly auricled at base, upper surface of wings from margin up to 3 mm turns blue when mature, lower surface white; keels lanceolate, 2.8–3.0 cm long, 1.2–1.3 cm wide, both surfaces turn light blue when mature. Ovary pubescent. Pod oblong, globose, unilocular, continuous 6.1–7.5 cm long, 3.9–4.0 cm wide, base rounded, apex aligned with longitudinal axis of fruit, with a green hook, surface glabrous, green with irregular brown marks, dehiscing longitudinally along both sutures. Seeds smooth, symmetrical, 2–3 in a pod, dorsal portion flattened, ventral portion inflated, 2.7–3.1 cm long, 2.1–2.4 cm wide; seed position transverse to fruit length; funiculus whitish, running along ventral side of seed, when mature funiculus is detached leaving a flat scar; hilum linear, around 1.6–1.8 cm of seed, white, with light brown rim; raphe visible; seed coat maroon and shiny when fresh, turning dark brown, papery and wrinkled when mature, not adhering to inner fruit wall.
Morphological comparison of Strongylodon juangonzalezii sp. nov. with other Philippine species of Strongylodon.
Characters | S. juangonzalezii | S. caeruleus | S. elmeri | S. lucidus | S. macrobotrys | S. pulcher | S. zschokkei | S. loheri |
---|---|---|---|---|---|---|---|---|
Terminal leaflet | ovate-elliptic | ovate | elliptic to ovate-elliptic | ovate, wide ovate or orbicular | elliptic to ovate-elliptic | ovate-elliptic, elliptic or oblong | elliptic or ovate | ovate |
Size of terminal leaflet (cm) | 10.4 × 6 | 11–19.5 × 6.5–11 | 10.5–19 × 3.5–7 | 0.6–1.3 × 0.55–0.9 | 12–15.5 × 5.5–7.3 | 13–22 × 4.2–13 | 8.5–16 × 3.3–6.7 | 10–15 × 6–7.5 |
Lateral leaflet | broadly ovate | ovate | ovate | ovate | ovate | oblong | ovate | ovate |
Size of lateral leaflet (cm) | 9 × 6.2 | 9–16 × 4–8 | 7.5–16 × 3–7 | 5–12 × 3–8 | 9–15 × 3.5–8 | 11.5–19 × 4.5–10.5 | 9–13 × 2.8–6 | 10–13.5 × 4.5–5.5 |
Flowering habit | dense plagiotropic raceme | axillary raceme | compact, subglobose, terminal raceme | pendulous, terminal raceme | pendulous, axillary to terminal raceme | pendulous, terminal raceme | pendulous terminal raceme | pendulous raceme |
Length of inflorescence axis (cm) | 13–27 | 21–24 | 18–60 | 5.5–30 | 150 | 3.5–11 | 19–29 | 10–19 |
Brachyblast | warty | cylindric | warty | warty | warty | cylindric | warty | warty |
Number of flowers in a cluster | 7–9 | 7–14 | no available data | 2–3 | 5–8 | 4–10 | 4–7 | 5–6 |
Color of flowers | Lilac when young, then blue when mature | purplish-blue | bluish-green | orange-red | bluish-green | purplish-blue | purplish-blue | purplish-blue |
Pedicel length (cm) | 1.7–1.9 | 1–1.8 | 3 | 1.0–2.8 | 1.8–4 | 1.5–2.0 | 1.8–2.3 | 2.3–2.5 |
Calyx | lilac, cup-shaped | purplish, campanulate | green, campanulate | green, campanulate | purplish, campanulate | green, campanulate | blue, campanulate | green, campanulate |
Standard petal | lanceolate, | ovate–lanceolate | ovate | lanceolate–ovate | ovate, reflexed | lanceolate | ovate, reflexed | oblong |
Size of standard petal (cm) | 2.5–2.6 × 1.3–1.4 | 2.6–2.8 × 1.2–1.6 | 2–3 × 1.1–1.6 | 1.7–3.1 × 1–1.2 | 3.7–4.8 × 1.7–2.5 | 2.1–2.5 × 0.9–1 | 2.9–3 × 1–1.5 | 3–3.3 × 1.8–1.9 |
Wing petal shape | oval | oblong | oblong | oblong | oblong–elliptic | oblong | oblong | oblong |
Size of wing petal (mm) | 12–14 × 6–7 | 12–14 × 5–7.5 | 11–13 × 5.5–7 | 7–11 × 3.5–6 | 20–24 × 8–10 | 8–11 × 3–4.5 | 10–13 × 5–6 | 14–17 × 7–9 |
Size of keel petals (mm) | 28–30 × 12–13 | 27–28 × 4–6 | 20–28 × 6–8 | 14–28 × 4–9 | 45–48 × 11–13 | 21–23 × 4–5 | 26–28 × 5–6 | 29–35 × 7–9.5 |
Pod shape | oblong, globose | elliptic, inflated, rugose | elliptic, rugose | elliptic to elliptic-orbicular | elliptic, inflated, rugose | elliptic, inflated, rugose | elliptic, compressed | oblong or elliptic, inflated |
Size of pod (cm) | 6.1–7.5 × 3.9–4.0 | 3.5 × 2.1 | 4–7.5 × 2.2–4 | 3–8 × 2–4.5 | 8.5–13 × 6 | 5.5 × 3.5 | 9 × 3.5 | 4.5–6 × 2–2.5 |
Altitude (m) | 295 | 500–1200 | low to medium altitude up to 1600 | 0–1500 | 110–1000 | 80–1200 | ca. 1400 | 1300–1900 |
This new species is named after Dr. Juan Carlos Tecson Gonzalez, current director
So far only two thriving lianas of this species are known from Buenavista Protected Landscape, Mulanay, Quezon Province where it was collected.
This liana thrives in a disturbed secondary growth forest climbing atop a large tree at an altitude of 295 m. The area is adjacent to an old coconut plantation.
Flowering and fruiting from February to mid-March.
Other species of Strongylodon collected in the Philippines were also examined.
Strongylodon caeruleus Merr., Luzon Island, Laguna Province, ML Steiner 1742, March 1959, (
Strongylodon elmeri Merr., Luzon Island, Laguna Province, ML Steiner s.n., 17 April 1955, (
Strongylodon macrobotrys A. Gray Exsicc. Gates CA 1442, 1443, 1444; Hernaez CA 12426; Orlido CA 10250; Pancho CA 18190, Reyes CA 2921 (CAHP);
Strongylodon pulcher C.B. Robinson, Mindanao Island, Agusan Province, C. Mahesa & J. Escasina s.n., 23 February 1967, (
Strongylodon zschokkei Elmer, Luzon Island, Mountain Province, M. Celestino s.n., 13 March 1948, (
All the materials used in this study were collected from a single population known only from the type locality in a region that is still poorly known botanically. This was the first documentation done inside the protected area. We suggest the preliminary conservation status of this species as Data Deficient (DD; IUCN 2014) and endemic to Luzon Island.
Strongylodon juangonzalezii exhibits plagiotropic branches where the dense racemose inflorescences are attached. In the wild, two colors of the flowers are exhibited – lilac color can be observed in young or newly-opened flowers while the mature ones are blue. This is quite remarkable compared with other species of Strongylodon whose flowers retain the same color from bud to fully opened stage. Its pod is oblong and globose while the rest of the species are elliptic. Three shapes of wing petals exist in Strongylodon. It is oval in S. juangonzalezii, oblong on S. caeruleus, S. elmeri, S. lucidus, S. pulcher, S. zschokkei, S. loheri and oblong-elliptic in S. macrobotrys. Calyx shape of S. juangonzalezii is cup-shaped which makes it distinct from the rest. Compared with the other species, S. juangonzalezii occurs at lower elevation.
1 | Inflorescence a raceme, attached on plagiotropic branches; flowers lilac when young, blue when mature; calyx cup-shaped, lilac colored | S. juangonzalezii sp. nov. |
– | Inflorescence a pendulous or drooping raceme; flowers same color all throughout; calyx campanulate, colors various | 2 |
2 | Brachyblasts cylindric; flowers purplish blue | 3 |
– | Brachyblasts warty; flowers variously colored | 4 |
3 | Flowers axillary; calyx purplish | S. caeruleus |
– | Flowers terminal; calyx green | S. pulcher |
4 | Inflorescence axis > 50 cm long; calyx purplish; flowers bluish green, standard petal 3.5-4.5 cm long, wing petal oblong-elliptic | S. macrobotrys |
– | Inflorescence axis < 50 cm long; calyx green to blue; flowers various, standard petal shorter than 3.5 cm, wing petal oblong | 5 |
5 | Calyx green | 6 |
– | Calyx blue | S. zschokkei |
6 | Inflorescence in compact, subglobose clusters | S. elmeri |
– | Inflorescence in loose, drooping clusters | 7 |
7 | Flowers orange-red, 2–3 in a cluster | S. lucidus |
– | Flowers purplish-blue, 5-7 in a cluster | S. loheri |
Permission to collect and transport specimens of Strongylodon juangonzalezii for scientific research was covered by the Wildlife Gratuitous Permit No. R4A-WGP-01-2015-QUE-001 issued by the Department of Environment and Natural Resources (DENR) – Region 4A, Calamba, Laguna. Ms. Mary Ann O. Cajano (deceased 6 December 2015) was part of the team who conducted fieldwork in Mulanay, and she is a co-author of the species S. juangonzalezii. The authors of the paper are grateful to the following staff of the LGU-Mulanay, Quezon Province for their generous support in the field collections: Hon. Joselito Ojeda, Municipal Mayor; Noel M. Eroa, Budget Officer; Engr. Delio H. De Leon, Municipal Engineer; Marcelino Mabini R. Asia – MENRO; Sanny P. Cortez, TSOO/MDRRMO; Linar T. Pereda, Exec. Assistant for Agriculture; Sofronio V. Tesalona, Tourism Assistant; Eymard C. Angulo, IDS Coordinator; Maribeth P. Liwanag, Administrative Aide; Wilfredo B. Mabini and Domingo T. Albaciete, Laborers, Hazel Recalde, Protected Area Superintendent and Pedrito A. Recalde, Field Technician from CENRO-Catanauan. Heartfelt thanks to Dr. Luisito Evangelista of the Philippine National Herbarium (PNH) for allowing access of Strongylodon specimens; Dr. Edwino S. Fernando, MNH Forestry Herbarium (LBC) Curator, for his valuable inputs; Dr. Ireneo L. Lit, Jr. and Mr. Lester Bautista for the Latin translation, Florante A. Cruz for the photoediting, Rafael D. Tandang, for the scientific illustration and Enrico M. Laluan for the digitized map.