Agatea

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Agatea

Description

Scandent shrubs to lianas, innovations mostly laxly pubescent, indumentum sometimes persistent. Leaf blade thinly to thickly coriaceous, c. 9-13 by 4-9 cm, index c. 1.6-2.2(-2.6); Leaves in a spiral, petiolate. Stipules deltoid, c. 1 mm long, persistent, often inconspicuous. Inflorescences racemes but mostly panicles, few to 30 cm long, axillary and terminal mostly combined, pubescent; Flowers bisexual, zygomorphic. Sepals subequal, 1-2 mm, covering a minor part of the bud, not persistent. Petals unequal, sessile, the posterior also outer pair c. 3-4 mm, symmetrical, the middle pair somewhat larger, asymmetrical, the inner, anterior one c. 7-10 mm, the base gibbose, the apical part wide, thus making a lip, in bud longitudinally rolled up, surface sometimes woolly above. Fruit (see note) a capsule, elongate, 1¼-5 cm, with 3 leathery to woody valves. Seeds many, imbricately arranged, flat, with an irregularly elliptic wing;

Distribution

Asia-Tropical:, New Guineapresent New Caledonia: present Pacific:, Fiji (Fijipresent); Tonga (Tongapresent) Solomons: present
New Guinea, Solomons, New Caledonia, Fiji, Tonga. Number of species probably 1; see below.

Notes

The above generic description covers the whole diversity of the genus; the specific description applies to the New Guinea materials only. For the insignificant differences with the conspecific A. salomonensis , see the description of the only collection, KAJEWSKI 2309 (A! BO! BRI! P!), from Bougainville.
A cursory inspection of several dozens of Fiji and New Caledonian plants revealed that no two specimens match in all details — in climbers not an unusual feature. But while all plants from Fiji were placed under A. violaris, in New Caledonia, where there is no more diversity than in Fiji, 7 species were described, on trifling characters and mostly without fruits; see . The differences can be summarized: in Fiji generally the young parts are sometimes glabrous, the stipules sometimes wanting, the leaves acute and tending to be ovate, with (sub)entire margin, the inflorescence up to 7(-14) cm, the lip 5-7 mm; in New Caledonia the young parts are mostly hairy, the stipules always present, the leaves acuminate and widest at the middle, with often an incised margin, the inflorescences up to 6-20 cm, the lip 6-9½ mm. The few fruits collected in New Caledonia are 12-34 mm long, the valves thick-coriaceous and covered with a grey felt, the seeds are c. 11 by 6-7 mm. The dozen or so fruiting numbers from Fiji have valves 23-50 mm long, thin-woody and mostly glabrous but in SEEMANN 12 (unripe) and A. C. SMITH 346 (ripe) they are more or less felty, too; the seeds are 13-22 by 9-10 mm, depending on the size of the fruit. As the fruit characters seem to overlap, and regional differences are so slight, a comprehensive study of this genus may well result in the retention of only one polymorphic species, A. violaris. MELCHIOR'S sections Macrobotrys and Euagatea, based on subtle differences in the filamental gland, are to be reduced anyway.
BRONGNIART'S alteration of the name to Agation for fear of confusion with Agathaea (Compositae) seems unnecessary.
A fine description of the ripening and dehiscence of the fruit was given by ; the same text occurs in . The “wing” of the seed is in fact a flattened and enlarged part of its funicle, which grows out mainly towards base and top, its irregularities in shape due to cramming in the fruit. The approximately triangular seed is pressed against the outside of its wing, dull grey-brownish as is the rest of the wing outside; the wing otherwise glossy dark purple-blackish. When ripe, the valves, firm in texture and boat-shaped, split while the strap-shaped basal part of the funicles remain attached to the receptacle, tearing loose gradually towards the top.

Citation

GUILL. - in Bull. Soc. Bot. Fr. 1942: 20
BAKER f. - in J. Linn. Soc. Bot. 1921: 263
A. GRAY - in Bot. U.S. Expl. Exp. 1854: 89
BRONGN. & GRIS - in Ann. Sc. Nat. 1864: 346
GUILL. - in Ann. Mus. Col. Mars. 1911: 98
B. & H. - in Gen. Pl. 1862: 118
A. C. SMITH - in Sargentia. 1942: 57
A. GRAY - in Bull. Mus. Hist. Nat. Paris. 1920: 362
F. SARASIN & Roux - in Nova Caled. B. 1921: 184
MELCH. - in E. & P., Nat. Pfl. Fam., ed. 2, 21. 1925: 360
A. GRAY - in Bull. Mus. Hist. Nat. Paris. 1911: 350
BRONGN. - in Bull. Soc. Bot. Fr. 1861: 80