Protium aidanianum, a New Species from Western Amazonia. Studies in Neotropical Burseraceae XII Douglas C. Daly Institute of Systematic Botany, The New York Botanical Garden, Bronx, New York 10458-5126, U.S.A. ddaly@nybg.org A ISr A\(:1'. Protium riiduniarnun (Burseraceae), a distinctive new species from western Amazonian Ecuador and Peru, is described, illustrated, and discussed. It resembles P. nodulosum Swart be- cause of its large. coriaceous leaflets and large, brownish, subslipitate. lenticellate fruits. but the new species has leaves 5- or 6-jugate (vs. 2- to 4- jugate). lateral lealetl lase Iruncate to slightly cor- late (vs. usually acute). inflorescence shorter than the petiole of the subtending leaf. flowers 4-merous (not 5-mlerous), petals glalrous and not persistent in fruit (vs. publescent and often persistent anm re- flexed in young fruits). pistillole glabrous, and fruit larger and with rounded (vs. acuminate) apex. It resembles P/ gllarescens Swart due to its robust branchlets. the inflorescence shorter than the pet- iole of the subtending leaf, and the petiole often turning black and exfoliating, but the new species differs by its deeply canaliculate petiole, higher- orler venation ilmpressed adaxiallv. shorter pedicel. petal margin long-papillate, and fruit brown or cof- fee-colored and much larger. The fact that only I of the 16 collections known to date has flowers highlights both the difficulty of finding flowering material and the need to actively seek it, particru- larly for dioecious tropical trees with small green flowers. Key uwords: Amlazonia, Ilurseraceae. Ecuador, Neotropies. Peru. Protiunm. )ocumentation of the Neotropical flora has im- proved signilicantly over the past 30 years, but the increase in collections of new taxa ant p)rogress toward more realistic distribution recordls has not been mlatiched by an increase in the proportion of systelmatically useful collections. Particularly in light of the recent surge in developmental studies for lphylogenetic work (e.g., Costello & Motley, 2001), adequate lrepresen'tation of a species ulti- tiately requires collections for every develolpmental stage of inflorescences, flowers, and fruits, as well as seeds, germinating s s, a ses l seedlings. As in many tropical tree groups, the flowers of IBurse'raceae are small, green (usually), and unisex- ual (nost), the latter ilmplying the need for flowering material firom bioth staminate and pistillate individ- uals. Moreover', for many taxa the flowers persist only a short lilme. The net result is that tropical systemiatists have cabinets full of new taxa repre- sented by material insufficient for full description andl therefore publication. Two strategies can com- pensate for this: first, botanists collecting tropical trees should always use binoculars to assist in lo- cation of flowering trees; and secondl, phelological studies often help to catch trees that have short flowering tphases. Meanwhile, the following new species fromi Aiiazonian Ecilador and Peru is rep- resented by 16 collections, but 3 are sterile, 12 have fruits (most with inmnature fruits), and I has buds antd a few stamninate flowers only. Protium aidanianum Daly, sp. inov. TY'PE: Ec- ualoir. Napo: Ia Joya de los Sac(has. Ponlpeya, S side of Rio Napo. Rio Jivino, Maxus Camp, km 5-7 Maxus Road. 00�25'S. 76�37'W, 220 m. 22-24 Aug. 1992 (fl) . . Grijalra & E. Gu- diino 2 (holotype, NY 121; isotylpes MO, QCNE). Figure 1. Arlbor mnetliocris vcl granitis foliola graintia coriacea friucltus granltlis tbrunetolus lenti'ellaltus a P/ noduloso fo- liolis S-6-jugatis (non 2-4-jugatis) infloreseentia petiotlo breviore floribus 4-plartilis (inee 5-tpartitis) petalis glaln'is fructlu grandiore apice rotililto dliffert. A P. glabrescenti ncrvis tertiariis adaxialibus i t)pre'ssis pedir cllis blreviori- bus petalis longo-plapillatis frliutu graldiore lbrieo(lo (nee rubell)) differt. Tree, reproductive height (6)10-30 m x 12-50 em; buttresses present at least sometimnes ("high" in Pinkley 478 in sched., at base in SEF 10367); bark gray-green, smootih, outer bark 2 unin thick on small trees (SEF 10.367), inner bark yellow-brown: )brlanhlets robust, to 1.5 m(' dliamn. proximal to apex: trichomes of four types: rnalpighiaceous hairs with lateral length ca. 0.2 rnm; fine erect "bristles" to 0.05 nmn long (to 0.1 m on adaxial mniivein): cap- itate glands: and thick golden appressed hairs to 0.1 tnm long, these mostly at inflorescence branch- ing points. ,Leae.s 5- to 6-jugate, 43-90 cmn long; petiole 7-31 (l X 6--9 imn, toward the base deeply NOVON 15: 410-413. PumlHsitSHI) ON 21 SEIT:Mt: 2005. Volume 15, Number 3 2005 Daly Neotropical Burseraceae XII Figurre . Protiimn aidanianum I)aly. \. lPortion of leaf. wiitl ins(et showing detail of petiolulr. --BI. \iung inflo- rescCInc arising from leaf axil. -C(. taininate huld. -I). Staminate fliowr with part of e