Strongylodon juangonzalezii Hadsall, Alejado & Cajano, 2016

Hadsall, Annalee S., Alejado, Michelle DR., Larona, Ariel R. & Lambio, Ivy Amor F., 2016, Strongylodon juangonzalezii, a remarkable new species of Strongylodon (Fabaceae) from Mulanay, Quezon Province, Philippines, PhytoKeys 73, pp. 1-12 : 2-5

Strongylodon juangonzalezii Hadsall, Alejado & Cajano sp. nov. Figures 2 , 3 , 4

Diagnosis.

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.

Type.

PHILIPPINES. Luzon, Island, Quezon Province, Municipality of Mulanay , Barangay Buenavista , Sitio Maglayaw , Buenavista Protected Landscape (BPL), 13°31'20"N, 121°24'15"E, 295 m, 5 February 2015, Cajano & Alejado 7708 (holotype CAHUP 73152!, isotype PNH) .

Description.

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.

Etymology.

This new species is named after Dr. Juan Carlos Tecson Gonzalez, current director UPLB-MNH, professor of zoology, one of the Philippines ten outstanding young scientists in 2011, a passionate conservationist and ornithologist.

Distribution.

So far only two thriving lianas of this species are known from Buenavista Protected Landscape, Mulanay, Quezon Province where it was collected.

Habitat and ecology.

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.

Phenology.

Flowering and fruiting from February to mid-March.

Additional specimens examined.

Other species of Strongylodon collected in the Philippines were also examined.

Strongylodon caeruleus Merr., Luzon Island , Laguna Province, ML Steiner 1742, March 1959, (PNH) ;

Strongylodon elmeri Merr., Luzon Island , Laguna Province, ML Steiner s.n., 17 April 1955, (PNH) ;

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, (PNH); Visayas Island, Leyte Province, G.E. Edano 14235, 15 March 1950, (PNH); Mindanao Island , Bukidnon Province, MD Sulit s.n., 10 March 1949, (PNH); Visayas Island , Leyte Province, G. Edano s.n., February 1923, (PNH) ;

Strongylodon zschokkei Elmer, Luzon Island , Mountain Province, M. Celestino s.n., 13 March 1948, (PNH) .

Conservation status.

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.

Discussions.

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 Strongylodon juangonzalezii , oblong on Strongylodon caeruleus , Strongylodon elmeri , Strongylodon lucidus , Strongylodon pulcher , Strongylodon zschokkei , Strongylodon loheri and oblong-elliptic in Strongylodon macrobotrys . Calyx shape of Strongylodon juangonzalezii is cup-shaped which makes it distinct from the rest. Compared with the other species, Strongylodon juangonzalezii occurs at lower elevation.

Figures

Figure 2. 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.

Figure 3. Voucher specimen of Strongylodon juangonzalezii sp. nov.

Figure 4. Strongylodon juangonzalezii sp. nov. A inflorescence B inflorescence showing point of attachment C opened pod to show seeds D young pod E mature seeds from the wild. Photographs by Mary Ann O. Cajano (deceased 6 December 2015) and Michelle DR. Alejado.