Inocarpus ademanus W.N.Takeuchi, 2012

Takeuchi, Wayne, 2012, Modern sequels to the Kaiserin-Augusta-Fluss itinerary of Carl Ledermann: floristic discoveries from the upper Sepik of Papua New Guinea, Phytotaxa 60 (1), pp. 17-31 : 27-30

Inocarpus ademanus W.N.Takeuchi , sp. nov. ( Fig. 11 )

Inter speciebus congeneribus singularis fructibus lanuginosis stylis lateralibus statim distinguitur. Type: — PAPUA NEW GUINEA. East Sepik Province: Ambunti District, Waskuk Hills, buttress ridge above Bangwis , foothill forest, 4°12'39"S, 142°46'34"E, 185 m, 2 January 2005, Takeuchi, Towati & Ama 17766 (holotype L! [2 sheets]; isotypes A! [2 sheets], B!, BO!, CANB!, K!, LAE! [3 sheets], US!).

Canopy tree, 25–30 m tall, all vegetative parts glabrous. Branchlets compressed-angulate, 1–3 mm across, grayish-brown (or fuliginous), lenticellate, fragile, often zig-zag; older periderm orange-brown, longitudinally channelled, vernicose; internodes (10–) 16–40 mm long. Leaves alternate, distichous, obliquely spreading; stipules early-falling, absent from fruiting branchlets; petioles pulviniform, 2–5(–7) × 1–3.5 mm, transversely wrinkled or fissured, discolorous, dull black, proximally articulated, easily dislodged by casual handling; leafblades elliptic (or ovate), (4.2–)5–8.9(–10.3) × (1.9–) 2.6–5.2 cm, subcoriaceous to firm, brunnescent, undersurfaces minutely black-spotted (glandular) in reflected light, laxly pellucid-punctate in transmitted light; lamina base rounded (or subcuneate), equal; margins entire; apex acuminate, acumen (3–)6–13 × 2–6 mm, usually obtuse at the top; venation brochidodromous-reticulate; secondaries 4–8 per side, 3–22 mm apart, filiform, straight, at the lamina center with divergence angles of 40–55°, abruptly closing by supramedially looping nerves, anastomosing beyond the loops; partial intersecondary veins numerous, as strong as the complete laterals; reticulum tessellate, irregular, finely areolate; midribs adaxially ± flat, abaxially prominent, higher order nervation weakly raised on both sides. Inflorescence not seen. Infructescence axillary, racemose, simple (or binately branched from the base), epedunculate; axis 2–9 × 2–4 mm, orange-brown pubescent; bracts crowded, cup-shaped, caducous (only the scarious bases present); pedicels cylindrical, 3–8 × 2–3 mm, distally articulated. Fruits rotund to suborbicular, 21–30 × 24–30 mm, asymmetric, indehiscent, 0.5–2 mm stipitate; indument (between galls) densely lanuginose, ferruginous, obscuring surfaces; exocarp galls crateriform, 1–4 mm diameter, glabrous, black, conspicuous, often congested; style base umbonate, inserted at right angles to the fruit axis; seed single.

Etymology: — Inocarpus ademanus is named after Frits Adema (Nationaal Herbarium Nederland), a specialist in Fabaceae and Sapindaceae .

Field characters: —Canopy tree 25–30 m tall, buttressed, trunk slash sparsely exuding red sap, wood dense; leaf-blades firm, dark green above, light green underneath; fruits flat, green.

Distribution: —Known only from the type locality in the Ambunti District of East Sepik Province ( Fig. 12 ).

Habitat and ecology: —Tall-statured canopy in hill forest, 185 m. Rare (seen only once during the multiyear surveys).

Phenology: —Fruiting in January.

Inocarpus Forster & Forster (1775: 33) has been treated by Verdcourt (1979) and Adema (2007). Three species were previously recognised within a generic range extending from western Malesia to the central Pacific (Marquesas, Society and Austral Islands; see Smith 1985). New Guinea is the only geographic station with all of the known species ( Adema 2007).

The generic identity of the new tree is clearly indicated by its canopy stature, red sap, apparently simple leaves, compressed-asymmetric fruits, and single seeds. Only an Inocarpus would have these qualities in combination. The single-blade leaves in particular are not like a typical legume. Transversely rugose-fissured petioles (discolorously black after drying) are also indicative of the assigned genus ( Balgooy 1997: 60–61). Although Smith (1985) regarded the leaves of Inocarpus as being genuinely simple, the pulviniform petioles suggest the single blades have been derived by reduction and are actually unifoliolate (F. Adema, pers. comm.).

Inocarpus ademanus is easily identified by the dense, rust-colored hairs covering the exocarp. Fruiting pedicels are 3–8 × 2–3 mm (not subsessile). Unlike its allies, the style base in I. ademanus is obviously lateral and inserted at right angles to the main axis. The fruit is flat—not merely compressed as in other species. Leaves are at the small end of the generic size range (largest blades only 10.3 × 5.2 cm) and unusually blackspotted on abaxial surfaces. Taken collectively, the character states in this new species are the most distinctive in the genus.

Mucuna lamii Verdcourt (1978: 463) . Type:— INDONESIA. Papua: Djajapura District, Cycloop Mts. , primary forest on sandy soil, 300 m, 31 May 1957, van der Sijde BW 5523 (holotype L).

Additional specimens examined: — PAPUA NEW GUINEA. East Sepik Province: Ambunti District, Waskuk Hills, ridge above Langu-Garuka track, anthropogenic regrowth, 4°11'28"S, 142°43'46"E, 55 m, 22 November 2004, Takeuchi , Towati , Jisaka & Ama 17364 ( A!, LAE!, and 2 undistributed duplicates!); crestline of low ridge north of Garuka , foothill forest, 4°11'09"S, 142°43'40"E, 280 m, 24 November 2004, Takeuchi, Towati & Ama 17433 ( A!, LAE!, and 5 undistributed duplicates!); Waskuk Hills, spur ridge near Musapien bivouac, hill forest, 4°10'36"S, 142°43'55"E, 360 m, 19 November 2007, Takeuchi & Ama 22223 ( A!, LAE!, and 2 undistributed duplicates!) .

The known localities for Mucuna lamii were previously restricted to western New Guinea ( Indonesia).

Lauraceae

Cryptocarya resinosa Kostermans (1968: 327) . Type:— INDONESIA. West Papua: Salawati Island, Kaloal , primary forest on level land, inundated in the wet season, 0 m, 29 October 1956, Versteegh BW 4666 (holotype L; isotypes A!, BO, CANB, LAE!, MEL, P, SING).

Additional specimen examined: — PAPUA NEW GUINEA. East Sepik Province: Ambunti District, Waskuk Hills, lowland forest near Garuka , 4°11'17"S, 142°44'15"E, 20 m, 14 November 2004, Takeuchi, Towati & Ama 17150 ( A!, LAE!, and 8 undistributed duplicates!) .

The distinction between Cryptocarya resinosa and C. weinlandii Schumann (1905: 270) is arguable. Kostermans (1968) accepted both species, but without specifically comparing them.

Only one distinguishing character for C. resinosa (viz. the white-spotted exudate on leaves and fruits) was mentioned in its description and protologue. Specimens cited as C. weinlandii (in Kostermans 1968: 340) can also have these spots (e.g., NGF 10243, 10306).

Cryptocarya weinlandii s. str. is found mostly in northeast New Guinea and the Solomons, while C. resinosa is historically known only from western (Indonesian) New Guinea. The Waskuk population provides a geographic link between the documented localities for C. resinosa and the westernmost station for C. weinlandii in PNG (previously Madang Province). If C. resinosa is accepted as a separate species, the Waskuk specimen is a country record for PNG. But given its pronounced similarity to C. weinlandii , it is unlikely that C. resinosa can survive future revision.

Moraceae

Ficus morobensis Berg (2004: 177) . Type:— PAPUA NEW GUINEA. Morobe Province: Huon Peninsula, Gang Creek, east slope of Mt. Rawlinson , secondary forest on creekbank, 4,300 ft (1,310 m), 12 June 1964, Hoogland 9140 (holotype LAE!; isotypes A!, CANB, K, L, US) .

Additional specimen examined: — PAPUA NEW GUINEA. East Sepik Province: Ambunti District, Waskuk Hills, Hantabas , hill forest, 4°10'36"S, 142°43'55"E, 550 m, 14 November 2007, Takeuchi & Ama 22071 ( A!, LAE!, and 2 undistributed duplicates!). Fig. 13 .

Ficus morobensis was recently described on the basis of three specimens from Morobe and Milne Bay Provinces. The Waskuk collection extends the geographic range 530 km to the northwest, into the northcentral tectonic zone.

Tectariaceae

Chlamydogramme hollrungii (Kuhn) Holttum (1986 publ. 1987: 157).

Gymnopteris hollrungii Kuhn in Schumann & Hollrung (1889: 8). Type:— PAPUA NEW GUINEA. East Sepik Province: Augusta-Station (Sepik River), July 1887, Hollrung 640 (holotype B,?lost; isotypes BO, K, L). Additional specimens examined: — PAPUA NEW GUINEA. East Sepik Province: Ambunti District, Waskuk Hills, ridgeline between Bangwis and Ambunti, 4°12'40"S, 142°46'42"E, 290 m, 2 January 2005, Takeuchi, Towati & Ama 17741 (A!, LAE!, and 4 undistributed duplicates!); Waskuk Hills, Mt. Musapien bivouac, hill forest, 4°10'36"S, 142°43'55"E, 360 m, 21 November 2007, Takeuchi & Ama 22295 (A!, LAE!). Chlamydogramme hollrungii is abundant in the Ambunti-Waskuk area, but is elsewhere known only from the Lakekamu basin on the opposite side of the Central Divide (e.g., Takeuchi & Kulang 11483). Although Chlamydogramme Holttum (1987: 157) has been consigned (e.g., in Smith et al. 2006, Christenhusz et al. 2011) to Tectaria Cavanilles (1799: 115) the appropriate nomenclatural transfer for Chlamydogramme hollrungii is still not available.

Figures

FIGURE 11. Inocarpus ademanus W.N.Takeuchi. A, aspect; B, fruits are ferruginous-hairy and conspicuously galled. A–B from Takeuchi, Towati & Ama 17766.

FIGURE 12. Island of New Guinea. A, Waskuk Hills, Ambunti District.

FIGURE 13. Ficus morobensis C.C.Berg. A, leaves with detached fig cluster; B, apical view of the fruits, showing ostiole bracts and discolorous lenticels on receptacle; C, longitudinally-sectioned figs. A–C from Takeuchi & Ama 22071.