Table Of Content

BLUMEA 41 (1996) 29-31 Alstonia beatricis (Apocynaceae), a new species from Irian Jaya, Indonesia Kade Sidiyasa c/oRijksherbarium/HortusBotanicus,Leiden,TheNetherlands INTRODUCTION Alstonia R.Br.(Apocynaceae) is a pantropical genus occurring in Africa, India, Indo-China, SoutheastAsia, Malesia, Australia, andeastwardstotheMarquesas Is- lands andCentralAmerica. IntheframeworkoftheInternationalMOFTropenbos KalimantanProject, are- visionofthegenusis inprogress.Alstonia comprises six sections andabout45 species. Onenew species fromIrianJaya,Indonesiais describedhere. Alstoniabeatricis Sidiyasa, spec. nov. Arborparva ramulis glabris.Foliaternatapetiolatalamina coriacea subtusferrugineaobova- tavel interdum elliptica apicebreviteracuminata basicuneatausque adinpetiolumdecurren- teintegrautroquelatere glabra.Inflorescentia multifloraumbelliformis. Sepalasubaequalia basiconnata turbinata apicerotundata ciliata. Corolla alba extus pro partepuberulatubo lobis ovatis paulolongiore. Stamina inclusa filamentis brevibus filiformibus antherisque ovatisapiceacutis basi cordatis. Pistillum glabrumovario late ovoideo. Fructusignotus.— Typus: vanRoyen 5535 (Lholo;A, BOiso),Indonesia,Irian Jaya, WaigeoIs.,pathfrom PoeantoTofakBay. Small tree, 5 m high. Branches smooth or slightly rough, withoutlenticels; branch- letsterete,3-angularor slightly sulcatewhendried,glabrous, pale brown.Leaves in whorls of3,petiolate; petiole glabrous, 10-20by 1-2mm, flattenedor shallowly canaliculateabove, withmanycolletersdensely together inthe axils; bladegreyor grey-greenabove,(reddish) brownbeneathand subcoriaceouswhen dried,narrowly obovate(sometimes elliptic),(2.6—)3.1—4.1 timesas long as wide, 6.2-16 by 1.5- 5.2cm, apex shortly acuminate,acumen upto 10mm long withabluntpoint, base acute to decurrentintothepetiole, entire, glabrous onboth sides; midribimpressed above; secondary veins in 12-16pairs, straight or ratherarched, forming anangle of70-80° withthe midrib,3-12 mmfromeach other, joining nearthemargin and forming a thinsubmarginal vein, shortinterstitialveins present; tertiary venation reticulate, usually inconspicuous onbothsides.Inflorescence 3-6.5cm long, many- flowered;peduncle 1.4-4.3cm long, 0.7-1.5mmin diam.,puberulous; pedicels 1-2 by 0.5-0.7 mm, softly pubescent (with very shortglaucous hairs).Bractsandbrac- teoles sepal- or scale-like, ovate to broadly ovate or triangular,0.4-0.9 mm long, obtuseoracute, ciliate, softly pubescent outside, glabrous inside.Flowers: sepals 5, connate at thebase for0.75 mm, turbinate,c. 1.7by 1 mm,apex rounded, ciliate, softly pubescent except atthefusedpartinside,erect, glaucous whendried.Corolla 30 BLUMEA —Vol. 41,No. 1, 1996 Alstonia beatricisSidiyasa. a.Floweringbranch;b. maturebud; c.pistil surrounded byannular disk- like thickening(corollaandcalyx removed);d.corolla lobefrom inside;e.corolla tube,dissectedand slightly stretchedtoshow 3 anthersinserted inthe glabrouszone. white, c.3 by 1 mminthemature budandforming anovoidheadc. 0.5thofthebud length (c. 1.5by 1mm), witha bluntapex,partly puberulous on thetubeand atthe lobemargins outside, blackish when dried, twohairy beltsinside, firstbeltsparsely pubescent starting fromc.0.8 mmabove thebaseand ending attheinsertionofthe stamens (c. 0.5 mm wide),the secondbeltpilose withwhitehairs atthebasal half ofthecorollalobes(around anthersglabrous); tubec. 1.2times as long asthe sepals, aboutas long as the lobes, c. 2mm long, almost cylindrical or slightly widened Kade Sidiyasa: Alstonia beatricis, spec. Nov. 31 aroundthestamens,c. 1.2mmwide; lobes 5, ovate, 1.6-1.8 times as long as wide, c.2by l.l-1.2mm,ciliate, apex rounded, auriculateatthebase attheright side.Sta- mens 5, with apex 0-0.2 mm below the mouthofthecorollatube, insertedatabout 65% ofthe length ofthecorollatube(at c. 1.3 mmfromthebase); filamentsc. 0.4 mmlong; anthers c. 0.7 by 0.3mm, apex acute. Pollenisopolar, 3-coIporate, 25.9 by 30.4(j.m;ectoapertures20(im longcol- pi; endoapertures lalongate pori, 7.6 by 8.2 |xm;tectum psilate, withminuteperfo- rations, usually somewhatrugulate in the Alstoniabeatricis Sidiyasa. Pollen grain.Scale centre ofa mesocolpium. Pistil 1.5 mm bar=5µm. long; ovary broadly ovoid, 0.4 by 0.6 mm, glabrous, consisting of 2 carpels, with an annulardisk-like thickening atthebase 0.15mm high; style 0.7mm long; pistil headovoid,0.4by 0.25 mm,composed ofathinbasal ring 0.15 mm high,a conical centralpart0.2by 0.2mm,andaminutecleftstigmoid apical part c.0.05mm high. Fruits unknown. Etymology —Namedto commemorate theopening oftheVan SteenisBuilding by HerMajesty Queen Beatrixon June11, 1996. Distribution—Knownonly fromthetypespecimen, reported (on label) as acom- mon smalltree species. Habitat&Ecology Low vegetation (open woodland) dominatedby Decasper- mum;70 maltitude. Note— Thepresentspecies is closely alliedtoA.parvifolia Merr., whichalsohas the leaves glabrous onboth sides.It differs from A.parvifolia in its muchsmaller flowers, very shortstyle(c.0.7mm versus 1.1-1.9mm) andthehairyoutsideofthe corollatube,which is mostly glabrous inA.parvifolia. ItalsoresemblesA. angusti- folia A.DC.andA. muelleriana Dominin leafshape andsize. It differsfrom these species in havingtheapical partofthecorollalobeglabrous inside.Alstoniabeatricis differsfromallthreespecies mentionedhereinitsshortercorollatube(c. 2mm versus 3-5.5 mm). ACKNOWLEDGEMENTS Iwould like tothank the directors/curators ofthe Arnold Arboretum,Herbarium Bogoriense, and especiallytheRijksherbariumatLeiden fortheirhospitality. Specialthanks aredue toProf.P.Baas for his stimulating support, toDr. A.J.M. LeeuwenbergatWageningenUniversity for his help with the Latindescription andto Mr. J.Kuijt andMs. B.J. van Heuven forthepollendescription and pollenphotograph,respectively. I also thank theTropenbosFoundation forprovidingagrant, andMr.Priyono, herbarium artist ofWanariset Herbarium,Samarinda,EKalimantan,Indonesia for makingthedrawing.