New species and species reports of Croton L. (Euphorbiaceae) from the eastern forest corridor of Madagascar Author Kainulainen, Kent Herbarium, Department of Ecology and Evolutionary Biology, 3600 Varsity Drive, Ann Arbor, Michigan 48108, U. S. A. Author Ee, Benjamin van Department of Biology, Universidad de Puerto Rico, Recinto Universitario de Mayagüez, Mayagüez, PR 00680, Puerto Rico, U. S. A. Author Antilahimena, Patrice Missouri Botanical Garden, B. P. 3391, Antananarivo 101, Madagascar. Author Razafindraibe, Hanta Parc Botanique et Zoologique de Tsimbazaza, rue Kasanga Fernand, Antananarivo 101, Madagascar. Author Berry, Paul E. Herbarium, Department of Ecology and Evolutionary Biology, 3600 Varsity Drive, Ann Arbor, Michigan 48108, U. S. A. peberry@umich.edu text Candollea 2016 2016-11-23 71 2 327 356 journal article 2894 10.15553/c2016v712a17 3ba10b86-da39-40e8-898c-ee3dfa6f0f05 2235-3658 5721805 Croton ankeranae Kainul. , spec. nova ( Fig. 1C , 2 ). Typus: MADAGASCAR . Prov. Toamasina: Atsinanana Region , Distr. Brickaville , Commune Maroseranana , Fokontany Ambodilendemy , Andrangato River , 18°26’37”S 48°46’31”E , 446 m , 13.III.2011 , Antilahimena 7554 ( holo- : MICH [ MICH1513200 ]!; iso-: MO !, P , TAN ). Croton ankeranae Kainul. can be distinguished from the similar small-leaved shrub Croton indrisilvae Kainul., B.W. van Ee & P.E. Berry by its taller habit (to 12 m vs. < 1 m ) and smaller leaves (4.5-10.5 × 3.9-6.3 mm vs. 9-28 × 5-12 mm ) that are entire (vs. crenate) with the apex acute to obtuse (vs. obtuse to rounded). Table 1. – Comparison of Croton L. taxa from the Ambatovy mining area between the PHILLIPSON et al. (2010) floristic survey of the Ambatovy-Analamay mine site and the present study.
PHILLIPSON et al. (2010) report This study
Croton alceicornu Radcl. -Sm. [ined.] Included under Croton hypochalibaeus Baill.
Croton droguetioides Radcl. -Sm. [ined.] Croton droguetioides Kainul. & Radcl. -Sm.
Croton hovarum Leandri Incorrect determinations, one is C. macrobuxus Baill. , another is C. hypochalibaeus Baill.
Croton humbertii Leandri Croton humbertii Leandri
Croton jennyanus Gris. ex Baill. Incorrect determinations, now Croton hypochalibaeus Baill.
Croton lepidotoides Radcl. -Sm. [ined.] Croton ferricretus Kainul., B.W. van Ee & P.E. Berry
Croton lichenisilvae Leandri Croton lichenisilvae Leandri
Croton macrobuxus Baill. ( var. uncertain ) Croton macrobuxus Baill.
Croton macrobuxus var. glandulifer Radcl. -Sm. [ined.] Not recognized here; it is insufficiently distinct from other populations of Croton macrobuxus Baill.
Croton nitidulus Baker Croton nitidulus Baker
Croton nitidulus var. cinereum Radcl. -Sm. [ined.] Not recognized here; the specimen cited as the type (in sched.) is Croton submetallicus Baill.
Croton noronhae Baill. Incorrect determination, now Croton hypochalibaeus
Croton sp. nov. A aff. C. nitidulus Baker We are not sure what this refers to
Croton sp. nov. B aff. C. jennyanus Gris ex Baill. Croton hypochalibaeus Baill.
Croton submetallicus Baill. Croton submetallicus Baill.
Croton thouarsianus Baill. Incorrect determination, this may correspond to Croton lasiopyrus Baill.
Croton trichotomus Geisel. Incorrect determination, now Croton macrobuxus Baill. or C. nitidulus Baker
[not previously recognized in the mine area] Croton catatii Baill.
[not previously recognized in the mine area] Croton enigmaticus P.E. Berry & B.W. van Ee
[not previously recognized in the mine area] Croton lasiopyrus Baill.
[not previously recognized in the mine area] Croton radiatus P.E. Berry & Kainul.
[near mine along pipeline, possibly planted] Croton mongue Baill.
[outside the mining footprint in offset area] Croton ankeranae Kainul.
[outside the mining footprint, in Analamazaotra National Park] Croton indrisilvae Kainul., B.W. van Ee & P.E. Berry
[outside the mining footprint, near Andasibe and on Andasibe-Lakato road] Croton plurispicatus P.E. Berry, Kainul. & B.W. van Ee
[outside the mining footprint, in Mandraka area and along road to Lakato] Croton goudotii Baill.
[outside the mining footprint, in Mandraka area and Mantadia National Park] Croton myriaster Baker
15 species and 2 varieties in mine area 13 species in mine area, 18 overall
Shrubs to small trees 0.8-12 m tall, dichotomously branching, internodes sometimes contracted giving the appearance of whorled branches. Branches ± flattened on new growth and densely covered by dark gray-brown fasciculate trichomes with rays c. 0.2 mm long, pale gray to whitish, becoming terete and glabrous with age. Stipules absent or vestigial. Leaves subopposite, ± congested at nodes. Petioles 0.7-1.8 mm , adaxially canaliculate, sometimes with a pair of acropetiolar, stipitate ( 0.2-0.4 mm long), discoid (c. 1.5 mm diam.) glands. Leaf blades thinly coriaceous, entire, (broadly) elliptic to obovate, 4.5-10.5 × 3.9-6.3 mm , apex acute-obtuse, base cuneate; adaxial surface glabrous, glossy, dark green when fresh and drying dark green; secondary venation indistinct; abaxial surface sparsely fasciculate, pale green when fresh and drying pale brown; secondary venation indistinct, midrib prominent. Inflorescences comprising 1-2 staminate flowers or a solitary pistillate flower, axillary or terminal; bracts triangular, c. 3.0 × 0.2 mm . Staminate flowers with fasciculate, subglobose buds c. 0.9 mm diam., pedicels to 1.5 mm long; sepals 5, shortly connate at base, lobes triangular to ovate, c. 0.7 × 0.3 mm , apex acute, inflexed at anthesis, abaxially fasciculate, adaxially glabrous, margins densely ciliate, pale green; petals 5, white, narrowly obovate to spatulate, c. 1.0 × 0.2 mm , recurved at anthesis, abaxially sparsely papillate, adaxially glabrous, margins densely ciliate; disc glands/nectaries 5, opposite the sepals, sessile, ellipsoid, c. 0.1 × 0.05 mm ; stamens 3-5, white, filaments c. 1.5 mm long, ciliate, anthers broadly elliptic, c. 0.2 mm long; receptacle pilose. Pistillate flowers with fasciculate-pubescent buds c. 0.9 mm diam., pedicels 0.5- 0.9 mm long; sepals 5, elliptic, spreading at anthesis, 1.2 × 0.6 mm , apex rounded, abaxially stellate-pubescent, abaxially sparsely fasciculate, pale green; disc glands/nectaries 5, opposite the sepals, sessile, ellipsoid, c. 0.3 × 0.2 mm ; glandular filaments (in petal position alternating with the nectary lobes) 5, linear, c. 0.5 × 0.07 mm , erect; ovary globose, c. 0.8 mm diam., densely stellate, styles 3, c. 2.5 mm long, bifurcate, spreading, recurved at the apices, with some fasciculate trichomes and a few pilose trichomes at the base, white, turning brown, persistent. Capsules 3-4 × 6-7 mm , smooth, with fasciculate trichomes; columella 2.8-3.5 mm long, cornute, capitate. Seeds not seen. Etymology. – The specific epithet refers to the Ankerana forest where this species is found. Distribution, Habitat and Ecology . – Croton ankeranae is to date only known from the Ankerana-Vohimanana montane forest in the Antsinanana Region of Toamasina Prov. , at 400- 1050 m elevation ( Fig. 1C ). Notes . – This species is probably most closely related to C. indrisilvae Kainul., B.W. van Ee & P.E. Berry described below, which has similar whitish stems with brown-fasciculate pubescence, small leaves with indistinct venation, and reduced inflorescences. However, both the leaves and flowers of C. ankeranae are smaller and among the smallest of any Malagasy Croton , and the staminate flowers have only 3 to 5 stamens. Paratypi . – MADAGASCAR . Prov. Toamasina : Atsinanana Region . Brickaville Distr. , Anjahamamy , Anivoranokely , Ankerana forest , 18°24’46”S 48°49’24”E , 768 m , 28.I .2012 , Antilahimena 8108 ( MO , P , TAN ); Maroseranana , Ambodilendemy , piste vers Vohimanana , 18°25’08”S 48°47’20”E , 1011 m , 24.III.2011 , Ravelonarivo et al. 3838 ( MICH , MO ); Ambatolampy , Vohimanana forest , 18°24’05”S 48°48’43”E , 927 m , 19.I .2012 , Ravelonarivo & Edmond 4082 ( MICH , MO , P , TAN ); Ankerana forest , 18°25’42”S 48°48’38”E , 695 m , X.2005 , Razakamalala et al. 2260 ( MO , P , TAN ).