Macropiper guahamense (C. DC.) A. C Smith

Piper guahamense C. de Candolle f. guahamense

Piper guahamense C. de Candolle in de Candolle, Prodr., 16(1):336, 1869.

Leaves and younger parts prominently puberulent.

Confined to Rota and Guam, so far as known, and the common form on Guam.

GEOGRAPHIC RECORDS AND SPECIMENS EXAMINED

MARIANAS ISLANDS.—s.l. Gaudichaud 163 (P, type).

Rota: Middle level plateau above Tataacho Point, 150–250 m, Evans 2058 (US, BISH, Fo, K).

Guam: s.l., LeGuillou in 1839 (P); Hombron in 1839 (P, 2 sheets); G.E.S. 387 part (US); Nelson 5 (US, BISH); Marche 101 (P); Merrill, 1914:71; Mt. Lamlam, summit, 400 m, Anderson 144 (US, BISH), 318 (US, BISH, Fo, DPU); Harmon-Barrigada road, west slope, Barrigada Hill, Stone 3782 (UG); east edge of Barrigada Point area, 400–600 ft [120–180 m], Moore 7 (US); Ritidian Point, 400 ft [120 m], Hosaka 3089 (US, BISH); Necker 159 (US); near Talisay, 150 m, Fosberg 35263 (US, BISH, Fo, NY, DPU), 150 m, Fosberg 35264 (US, BISH, Fo, DPU); Yigo, Whiting P10a (US, Fo); headwaters of Ylig River, Rodin 613 (US); Agaña, Seale in 1900 (BISH); Talofofo area, Pedrus 23 (BISH); Naval Magazine, Almagosa Springs Road, Stone 4105 (UG); Canada, Bryan 1074 (US, BISH); Maguao, 15 m, limestone, Bryan 1036 (US, BISH); Mogfog, 400 ft [120 m], Gressitt 2007 (US); southwest of Anao Point, 200 m, Fosberg 31938 (US, BISH, Fo, NY, L, DPU); one mile south of Taguac, 110 m, Fosberg 35478 (US, BISH, Fo, NY, L, DPU); Mataguac, Reid Moran 4438 (BISH, US, Fo, UC, MO); Anigua, 4 m, Fosberg 31214 (US, BISH, Fo, NY, L, DPU); near Mt. Tenjo, Swezey in 1936 (BISH); Tailalo, Reid Moran 4581 (US, BISH, Fo, UC); Andersen Air Force Base, Reid Moran 4404 (US, BISH, Fo, UC); north of northwest strip, Conover & Wagner 563 (BISH); Tarague Beach, Andersen Air Force Base, 0–25 m, Evans 731 (US, BISH, Fo, K); Lujuna, just off route 15, 180 m, Evan 1579 (US, UH, Fo, K, Mo, L); Dededo Well Field, 110 m, Evans 1692 (US, Fo, UH, K, P); Mt. Lamlam, track from Jumullong Mangio, 300–405 m, Evans 237 (US, Fo, P, L, BISH, MO); Mt. Lamlam, 370 m, Fosberg 46252 (US, Fo, UH, A, L); 46263 (US, Fo, UH, P, L, MO).

Piper guahamense C. de Candolle

Piper guahamense C. de Candolle in de Candolle, Prodr., 16(1):336, 1869 [type from Marianas, doubtless Guam, Gaudichaud 16].—Safford, Contr. U.S. Nat. Herb. 9:354— 355, 1905—Merrill, Phil. Jour. Sci. Bot., 9:71, 1914.—Kanehira, Fl. Micr., 418, 1933.—Hosokawa, Trans. Nat. Hist. Soc. Formosa, 25:117, 1935.—Kanehira, Enum. Micr. Pl., 305, 1935.—Bryan, Plants of Guam [unpub., 1946?].—Yuncker, Occ. Pap. Bishop Mus., 22:86–87, 1959.—Fosberg, Phytologia, 13:235–236, 1966.—Fosberg, Falanruw, and Sachet, Smithsonian Contr. Bot., 22:21, 1975.

Piper latifolium Gaudichaud ex Kunth, Linnaea, 13:575, 1839 [type from the Marianas, Gaudichaud 163] [non L.f., Suppl. Pl., [468], 1781].

Macropiper latifolium sensu Miquel, Syst. Pip., 219, 1843–1844 [non (Forster f.) Miquel, Comment. Phytogr., 36, 1840].

Macropiper methysticum Miquel, Syst. Pip., 217, 1843–1844 [non (Forster f.) Miquel, Comment. Phytogr., 36, 1840].

Piper macgillivrayi sensu von Prowazek, Deutschen Marianen, 115, 1913 [non C. de Candolle in Seemann, Fl. Vit., 262, 1868].

Erect to somewhat reclining shrub 1–3 m long, nodes prominent; leaves large, orbicular-cordate, slightly acuminate, 9- or 11-nerved from base, petioles shorter than blades, lower half expanded-sheathing; flowers dioecious or rarely monoecious, in solitary axillary pedunculate spikes, these usually shorter, sometimes longer, than the leaves, the staminate more slender than the pistillate, occasional spikes mixed, staminate and pistillate, peltate bracts imbricate when spikes are young; stamens 3, oval, bilocular; ovaries subtruncate at apex, crowded on spikes, rarely a few on staminate spikes (Rodin 613), stigmas 3–4, fleshy, tomentose; fruits connate, red.

Marianas records of Piper macgillivrayi C. de Candolle by von Prowazek (1913), Piper latifolium Gaudichaud by Kunth (1839), Macropiper latifolium Miquel by Miquel (1843–1844), and Macropiper methysticum Miquel by Miquel (1843–1844) are doubtless based on specimens of P. guahamense, although we have not seen these specimens, except that of Gaudichaud. None of these species is otherwise known from the Marianas.

The species is endemic to the Marianas, where it grows as an undergrowth shrub, in and around the edges of wet forests.

Two forms are known, one with leaves prominently puberulent beneath especially on nerves, petioles, peduncles, and young stems also puberulent, the other glabrous except the stigmas.