Conostegia D. Don

Kriebel, Ricardo, 2016, A Monograph of Conostegia (Melastomataceae, Miconieae), PhytoKeys 67, pp. 1-326 : 35-37

Conostegia D. Don

Conostegia D. Don, Mem. Wern. Soc. 4: 316. 1823. Lectotype: Conostegia procera (Sw.) D. Don ex DC. (= Melastoma procera Sw.), designated here.

Synodon Raf., Sylva Tellur. 95. 1838. Lectotype:- Conostegia montana (Sw.) D. Don ex DC.(= Melastoma montana Sw.), designated here.

Description.

Small shrubs to medium sized trees with slender and terete to stout and tetragonal branches; branches glabrous to variously pubescent with simple, stellate, stipitate-stellate, lepidote, or highly varying dendritic trichomes, usually the trichomes types not in combination. Twigs with or without nodal lines which can be obscured by the indument. Petiole absent or usually present, in one species ( Conostegia bigibbosa ) and some populations of another ( Conostegia montana ) with two tubercles near the apex abaxially. Leaves subisophyllous to isophyllous or rarely anisophyllous (most markedly in Conostegia henripittieri ), membranaceous, rarely coriaceous, several species with somewhat leathery texture, particularly the ones with a hypodermis, nerved to strongly plinerved and if the latter, frequently asymmetric, entire to crenate, denticulate or serrate, adaxially usually glabrous, abaxially glabrous to variously pubescent with simple, stellate, stipitate-stellate, lepidote, or highly varying dendritic trichomes, the surface obscured by indument in a few species, all species with tiny glands on the surface, the apex acute to caudate, the base peltate, rounded, cordate, acute or long decurrent, with pouch-like formicaria at the base in two species ( Conostegia dentata and Conostegia setosa ), with pocket domatia at the base abaxially in three species ( Conostegia ecuadorensis , Clidemia hammelii and Conostegia ombrophila ), and with evident tuft domatia in one species ( Conostegia procera ). Inflorescences pseudoaxillary or terminal, erect or deflexed, small dichasia or small to large panicles, few to many flowered, branching at or above the base, in a few cases the branches terminating in bracteate glomerules (i.e. Conostegia monteleagreana ), bracts and bracteoles deciduous and sometimes appearing absent, or persistent and especially the bracteoles sometimes forming a nodal collar around the inflorescence branches, accessory branches present especielly in taxa with terminal, paniculate inflorescences. Flowers diplostemonous or pleiostemonous, 4-12-merous; calyx calyptrate or not, if calyptrate with or without calyx teeth and the calyptras varying from very thin to very thick, glabrous to pubescent like the hypanthium and with or without sclereids, if the calyx not calyptrate, fused in some species and rupturing irregularly at anthesis into irregular lobes, in non calyptrate species the calyx lobes mostly inconspicuous and similar to the calyx teeth, not conspicuous except in Conostegia incurva ; petals reflexed or generally spreading, linear-oblong to broadly obovate, the apex acute to rounded, evidently clawed at the base at least on one species ( Conostegia schlimii ), mostly glabrous, in at least one species conspicuously papillose ( Conostegia papillopetala ), translucent to mostly white, in a few species pink or purple, the petals cells on the adaxial surface mostly rounded in species with colored petals and flattened in species with translucent petals. Stamens 8 to ca. 52, arranged neatly around the style in diplostemonous taxa and less neatly but similarly in most pleiostemonous taxa, a few species with the stamens bent to one side of the flower (i.e., Conostegia fragrantissima and Conostegia pittieri ), filaments translucent white to white, with or without an evident geniculation near the apex, the connective not prolonged nor appendaged, the filament anther insertion transitioning smoothly or with a “shoulder” or abrupt step, anthers linear, oblong, elliptic or ovate, apically rounded or acute, basally acute, rounded or sagittate, yellow, less frequently whitish or with pinkish hues, laterally compressed, with druses in the endothecium, the pore oriented totally upward, somewhat ventrally inclined or less frequently dorsally inclined, usually small, broad in one species ( Conostegia brenesiana ), anther sporangia positioned laterally or more or less superposed. Ovary from almost superior to usually totally inferior, 4-25 locular, the placentas within each locule laminar, triangular or peltate, with or without mucilage inside; the style exserted beyond the stamens or not, cylindrical and linear, to shaped as an inverted crateriform cone, when linear, sometimes gently bending to abruptly bending below the stigma, hollow or with a stele within, the stigma lobed or not, papillose. Berries small to large, mostly purple, sweet and usually pleasant to human taste; seeds mostly numerous ad small (ca. 0.5 mm long), few and large in a few species, largest in Conostegia osaensis (ca. 1.5 mm long), ovoid to pyramidal, sometimes evidently angular, the testa smooth in most species, tuberculate all over in some, and in fewer still, with the tubercles restricted to the angles.

Species concepts in this revision for the most part follow the morphological species concept as defined by Cronquist (1978) in which species are "the smallest groups that are consistently and persistently distinct, and distinguishable by ordinary means." It is a problematic concept partly because defining “distinct” is subjective and varies across organisms. Nonetheless, it is the most common species concept applied to plants (McDade 1995), and an effort was made to recognize only species that appear distinct. This author views species as hypotheses that are subject to testing. Thus the reader should be aware that some species may someday prove to be synonymous with others, and some species complexes might prove to be made of cryptic species in need of recognition. Properties of other species concepts are desirable, such as defining species based on monophyly (e.g. the phylogenetic species concept), but the lack of enough representative specimens in the phylogenetic analyses of many species, as well as appropriate molecular markers to ascertain clades (species) with confidence, and inherent biological processes such as incomplete lineage sorting, preclude much of its use in the present treatment. In this monograph when a negative measurement is given for the distance between the anther and the stigma, this means that the anthers are below the stigma for that length.

Key to the sections and species of Conostegia

1	Sepals not fused into a calyptra, sometimes rupturing late at anthesis into irregular lobes, calyx teeth present at the level of the torus or slightly above; flowers diplostemonous (sect. Geniculatae , pro majore parte)
2	Leaves discolorous, the abaxial surface white to rusty and concealing the surface
3	Sepals fused and rupturing at anthesis into irregular lobes
4	Sepals the same texture as the hypanthium, persisting through flowering; anther apex rounded	Conostegia centrosperma
4'	Sepals hyaline and almost not visible during flowering; anther apex acute	Conostegia dissitinervia
3'	Sepals not evidently fused at anthesis and rupturing into irregular lobes
5	Calyx teeth adnate to the calyx lobes, barely discernable and not projecting beyond them; petals papillose	Conostegia fulvostellata
5'	Calyx teeth oblong or linear, usually evident and exceeding the calyx lobes; petals glabrous
6	Abaxial indument rusty colored; calyx teeth usually longer than 2 mm and hooked	Conostegia incurva
6'	Abaxial indument white; calyx teeth up to 1.5 mm long and not hooked	Conostegia oligocephala
2'	Leaves not discolorous, the abaxial surface visible
7	Inflorescence axillary or appearing so
8	Leaves peltate; indument on abaxial leaf surface and hypanthia stellate; flowers 4-merous	Conostegia subpeltata
8'	Leaves not peltate; indument on abaxial leaf surface and hypanthia glabrous or stellulate lepidote; flowers 4-5 merous
9	Leaves and hypanthium glabrous or appearing so
10	Leaf base decurrent on the petiole and lacking domatia at the base abaxially; inflorescence of pedunculate glomerules with sessile flowers and ovate bracteoles	Conostegia fraterna
10'	Leaf base acute and usually with domatia at the base abaxially; inflorescence a laxly branched dichasium with pedicellate flowers and linear to lanceolate bracteoles
11	Leaves with four domatia located abaxially at the base of the leaf	Conostegia ecuadorensis
11'	Leaves lacking, or usually with two domatia located abaxially at the base of the leaf	Conostegia ombrophila
9'	Leaves and hypanthium densely pubescent with long simple or dendritic hairs (some populations of Conostegia allenii with glabrous leaves)
12	Petals acuminate at the apex	Conostegia trichosantha
12'	Petals rounded at the apex
13	Leaves with domatia at the base abaxially	Clidemia hammelii
13'	Leaves lacking domatia at the base abaxially
14	Leaves sessile or subsessile	Conostegia allenii
14'	Leaves distinctly petiolate	Conostegia foreroi
7'	Inflorescence terminal
15	Leaves peltate	Conostegia peltata
15'	Leaves petiolate from the lamina base or sessile, not peltate
16	Hypanthium densely covered with simple hairs sometimes intermixed with stellate hairs; the leaves with simple hairs on both surfaces or just on the abaxial surface; calyx teeth linear to subulate and 2-4 mm long	Conostegia allenii
16'	Hypanthium glabrous to densely covered with stellate and or dendritic hairs; the leaves adaxially glabrous and abaxially glabrescent to densely covered with stellate or dendritic trichomes mostly on the veins; calyx teeth tuberculate to triangular or, if linear, usually less, but up to, 2 mm long
17	Inflorescences with sessile flowers in bracteate clusters
18	Leaves sessile and the base decurrent	Conostegia povedae
18'	Leaves petiolate, the base obtuse to acute or rounded
19	Calyx lobes not evidently fused at anthesis and rupturing, ovate to orbicular and mucronate, the same consistency as the hypanthium	Conostegia colliculosa
19'	Calyx lobes fused at anthesis, hyaline, and rupturing into irregular lobes	Conostegia galdamesiae
17'	Inflorescences with pedicellate flowers not in clusters
20	Calyx fused in bud and rupturing into irregular hyaline lobes
21	Flower 4 merous	Conostegia calocoma
21'	Flower 5 merous
22	Leaves subsessile with rounded to cordate bases; plants overall appearing glabrous but bearing minute inconspicuous trichomes almost invisible to the naked eye; stamens alternately two sizes	Conostegia dissitiflora
22'	Leaves clearly petiolate or if short petiolate (sometimes in Conostegia papillopetala ) with acute to decurrent bases; plants evidently pubsecent, especially on the apical nodes and leaf abaxial surface; all stamens mostly of one size
23	Petals linear oblong; Costa Rican endemics
24	Leaves 5 plinerved; indument of stem apices of asperous headed hairs only; inflorescence branched at the base	Conostegia friedmaniorum
24'	Leaves 7 plinerved; indument of stem apices lanate at least in part; inflorescence branched above the base	Conostegia pendula
23'	Petals ovate; Panamanian endemics
25	Flower regularly arranged at the end of the inflorescence branches and with pink papillose petals	Conostegia papillopetala
25'	Flowers usually clustered at the end of the inflorescence branches and with white glabrous petals	Conostegia galdamesiae
20'	Calyx not fused in bud and the lobes not rupturing into irregular hyaline lobes, the lobes mostly low and undulate
26	Flowers large, the petals 9 mm long or more; stigma capitate; ovary totally inferior	Conostegia schlimii
26'	Flowers small, the petals usually no more than 5 mm long; stigma truncate to punctiform; ovary at least partly superior
27	Leaves 5-7 nerved with a broadly rounded to cordate base	Conostegia shattuckii
27'	Leaves 5-7 plinerved with rounded to mostly acute to attenuate base
28	Petals magenta	Conostegia jefensis
28'	Petals white
29	Petals ovate; anthers with broad pores	Conostegia brenesiana
29'	Petals linear-oblong; anthers with small pores
30	Leaves 3 plinerved, the leaf blade 1.7-9.5 × 0.4-1.7 cm	Conostegia iteophylla
30'	Leaves 5 plinerved, the leaf blade 4.2-28.4 × 1.4-9.2 cm	Conostegia consimilis
1'	Sepals fused into a calyptra, calyx teeth absent, or if present, restricted to the apex of the calyptra; flowers usually pleiostemonous
31	Calyptra often rupturing at one side or breaking into pieces; style exserted (section Australis and Conostegia cinnamomea )
32	Leaf bases with pouch like formicaria; indument of the stems with long simple hairs	Conostegia dentata
32'	Leaf bases without pouch like formicaria; indument of stems absent or of stellate, dendritic or asperous hairs
33	Stem apices and leaf abaxial surface glabrous or nearly so
34	Flowers in glomerules at the end of inflorescence branches and subtended by evident bracts and bracteoles; stamens usually less, but up to 15	Conostegia monteleagreana
34'	Flowers regularly arranged at the end of inflorescence branches and without evident bracts; stamens 16 or more in number
35	Inflorescence a reflexed and pseudoaxillary panicle; flowers (4-) 5-merous	Conostegia cinnamomea
35'	Inflorescence a terminal panicle; flowers usually 6-merous
36	Leaves with an entire margin and caudate apex	Conostegia tenuifolia
36'	Leaves with a serrulate to serrate margin and acuminate apex
37	Leaves linear to linear elliptic, up to 3.5 cm wide, attenuate at the base; stamens 16-21	Conostegia attenuata
37'	Leaves ovate, 2-7.3 cm wide, obtuse to rounded at the base; stamens 26-36	Conostegia polyandra
33'	Stem apices and leaf abaxial surfaces evidently pubescent at least on the veins
38	Leaf base strongly decurrent on the petiole; leaves sessile or nearly so	Conostegia ortizae
38'	Leaf base acute to rounded; leaves petiolate
39	Leaves linear to linear elliptic, up to 3.5 cm wide	Conostegia attenuata
39'	Leaves elliptic to ovate, more than 5 cm wide
40	Petioles setose adaxially; flower buds covered by foliaceous bracteoles	Conostegia lasiopoda
40'	Petioles glabrescent or variously pubescent, but not setose adaxially; flower buds not covered by foliaceous bracteoles
41	Floral buds up to 4(-5.5) mm long; petals up to 5 mm long; style lacking a collar around the base	Conostegia extinctoria
41'	Floral buds more than (4.7-)5.5 mm long; petals 7 mm long or more; base of the style enveloped by a collar
42	Indument on stems evidently stipitate stellate, not rusty colored; stamens more than 30	Conostegia lancifolia
42'	Indument on stems sometimes stipitate stellate but not evidently so, rusty colored; stamens up to 24
43	Flower buds (7.5-) 10-18 mm long, the apex long apiculate	Conostegia apiculata
43'	Flower buds 4.7-11 mm long, the apex rounded to short apiculate
44	Flower buds with the surface sparsely pubescent resulting in a visible surface, constricted below the torus; petioles 1-5 cm long	Conostegia centronioides
44'	Flower buds with the surface densely pubescent resulting in a hidden surface, not to slightly constricted below the torus; petioles 0.4-2.5 cm long	Conostegia rubiginosa
31'	Calyptra circumscissle and falling as a unit; style shorter or of equal length than the stamens (section Conostegia & section Geniculatae , pro minore parte)
45	Stigma lobed and/or with an evident hole in the middle
46	Flower buds pyriform to ellipsoid, with an attenuate to apiculate apex, longer than wide
47	Stem apices and leaf abaxial surface slightly pubescent to evidently pubescent; plants from Mexico
48	Stems and leaf abaxial surfaces furfuraceous	Conostegia jaliscana
48'	Stems and leaf abaxial surfaces densely beset with stellate and stalked stellate trichomes	Conostegia arborea
47'	Stem apices and leaves glabrous or with scattered stellate trichomes in Conostegia chiriquensis ; plants from Costa Rica and Panama
49	Flower buds 5-7 mm long; petals to 5 mm long, white with a red band at the base; anthers to 2.3 mm long	Conostegia fragrantissima
49'	Flower buds 7-14 mm long; petals at least 8 mm long, white to less commonly lavender; anthers at least 2.5 mm long
50	Stigma peltate and with a hole in the middle	Conostegia pitteri
50'	Stigma barely expanded and lacking a hole in the middle	Conostegia chiriquensis
46'	Flower buds mostly ovoid to spherical with a rounded, mucronate, or broadly acute apex, as long as wide or slightly longer than wide
51	Stigma capitate, but lacking a large hole in the middle; stigma lobes not conspicuous	Conostegia icosandra
51'	Stigma with large hole in the middle; stigma lobes conspicuous
52	Leaves with two tubercles at the apex of the petiole abaxially; petals pink	Conostegia bigibbosa
52'	Leaves lacking tubercles at the apex of the petiole abaxially; petals white
53'	Floral buds obovoid, constricted near the torus, acute at the apex, the surface smooth; leaves narrowly elliptic	Conostegia bernoulliana
53	Floral buds spherical, not constricted near the torus, abruptly mucronate apically, the surface inconspicuously to usually evidently tuberculate; leaves elliptic to usually ovate
54	Bracteoles replaced by persistent clusters of setae; pedicels up to 3 mm long	Conostegia setifera
54'	Bracteoles not consisting of setae, usually early deciduous; pedicels usually more than 3 mm
55	Style straight; petals apically retuse; leaves stellate pubsecent abaxially	Conostegia macrantha
55'	Style curved; petal apex rounded, truncate to emarginate; leaves stellate sometimes stellate pubescent abaxially when young, usually glabrous with age
56	Leaf margin entire to denticulate; floral buds usually conspicuously tuberculate; Nicaragua to Panama	Conostegia oerstediana
56'	Leaf margin undulate dentate; floral buds inconspicuously tuberculate; Guatemala and Mexico	Conostegia volcanalis
45'	Stigma not lobed or with a hole in the middle
57	Leaf bases with pouch like formicaria; indument of the stems with long simple hairs	Conostegia setosa
57'	Leaf bases lacking formicaria; indument of the stems various but not of long simple hairs
58'	Flowers subtended by persistent foliaceous bracts
59	Stems and leaves glabrous or with inconspicuous trichomes	Conostegia monteleagreana
59'	Stems and leaves densely pubescent with simple and somewhat branched trichomes	Conostegia bracteata
58'	Flowers not subtended by persistent foliaceous bracts
60	Leaves with the abaxial surface covered with white to tan trichomes, making the actual surface hidden or almost so
61	Abaxial leaf surface and hypanthium covered with lepidote trichomes; tree reaching about 25 meters tall; calyptra translucent, less pubescent than the hypanthium; seeds about 1.5 mm long; Endemic to the Osa Peninsula, Costa Rica	Conostegia osaensis
61'	Abaxial leaf surface and hypanthium covered with stellate trichomes; tree reaching about 15 meters tall; calyptra tan to whitish colored, not translucent, and as pubsecent as the hypanthium; seeds to about 1 mm long
62	Calyptra with linear appendages at the apex about 2.5 mm long	Conostegia plumosa
62'	Calyptra lacking linear appendages at the apex, at most minute bumps present on the apex	Conostegia xalapensis
60'	Leaves with the abaxial surface glabrous or pubescent, if pubescent, never with the surface hidden
63	Stem apices and leaf abaxial surfaces pubescent
64	Leaf adaxial surface and floral buds densely hirsute; inflorescence and bud pubescence purple	Conostegia speciosa
64'	Leaf adaxial surface glabrous and floral buds glabrous or beset with stellate or dendritic trichomes; inflorescence and bud pubescence rusty or whitish
65	Leaves 5-9 plinerved; flowers with small appendages on the calyptra apex; floral buds wider above the torus; petals apically slightly mucronate to acute, especially when seen at anthesis; filaments with an evident geniculation; seeds about 1 mm long	Conostegia subcrustulata
65'	Leaves 3-5 nerved or plinerved; flowers without small appendages on the calyptra apex; floral buds usually not wider above the torus; petals rounded, emarginate or truncate; filaments without an evident geniculation; seeds about 0.5 mm long
66	Floral buds, veins on leaf abaxial surface and stem apices rusty with small brown dendritic hairs; petals 7 or more mm long; ovary apex elevated into a conspicuous collar around the style base	Conostegia rufescens
66'	Leaf abaxial surface and stem apices sparsely to densely covered with stellate or stipitiate stellate trichomes, floral buds glabrous to sparsely or densely covered with stellate or stipitiate stellate trichomes; petals 6.5 mm long or less; ovary apex usually not elevated into a conspicuous collar around the style base (somewhat evident in Conostegia superba )
67	Stem apices, leaf abaxial surfaces and floral buds densely covered with sessile stellate and/or stipitate stellate trichomes
68	Leaf and bud indument combining sessile stellate and stipitate stellate trichomes; floral buds with the lobes slightly differentiated at the apex; plants from Cuba and the Dominican Republic	Conostegia lindenii
68'	Leaf and bud indument of stipitate stellate trichomes; floral buds with the lobes not differentiated at the apex; plants from Central America
69	Trees reaching 12 m high; Belize, Guatemala and Honduras	Conostegia caelestis
69'	Shrubs rarely reaching 4 m high; Costa Rica	Conostegia brenesii
67'	Stem apices and leaf abaxial surfaces sparsely to densely covered with stellate trichomes or sparsely beset with stipitate stellate trichomes, floral buds glabrous or sparsely beset with sessile or less commonly some stipitate stellate trichomes
70	Leaves 7.1-36 × 2.3-16 cm; inflorescence 7-27.5 cm long, with flowers disposed in umbels terminating the inflorescence branches	Conostegia superba
70'	Leaves 3.8-21.5 × 1.2-10.5 cm; inflorescence 2.7-18.1 cm, long with flowers not disposed in umbels terminating the inflorescence branches
71	Stem apices and abaxial leaf surfaces with sessile and stipitate stellate trichomes	Conostegia hirtella
71'	Stem apices and abaxial leaf surfaces with sessile stellate trichomes
72	Leaves densely stellate pubescent on abaxial leaf surface; lowlands of the Caribbean slope of Nicaragua, Costa Rica and Panama	Conostegia micrantha
72'	Leaves with trichomes mostly restricted to the veins; widely distributed	Conostegia montana
63'	Stem apices and leaf abaxial surfaces glabrous or with very inconspicuous trichomes
73	Inflorescence pendant; flowers with purple petals; seeds muriculate	Conostegia muriculata
73'	Inflorescence erect; flowers with white or pink petals; seeds smooth
74	Flowers sessile or on pedicels up to about 1 mm long	Conostegia montana
74'	Flowers on pedicels 1.5 mm long or usually longer than 2 mm
75	Flowers clustered at the end of the inflorescence branches; flower buds up to and usually less than 11 mm long; Southern Mexico (Oaxaca and Veracruz) through Central, and South America, only Conostegia superba reaching the Caribbean including Jamaica
76	Petals 7-12 mm; anthers 4-4.5 mm long; stigma capitate; bracteoles up to 6 mm long; flowers 6-8 merous	Conostegia cuatrecasii
76'	Petals to 6 mm, less commonly to up to 8.3 mm; anthers to 3.25 mm long; stigma cylindrical to slightly expanded; bracteoles absent or to about 1 mm long; flowers (4-)5-7 merous
77	Flower buds acute to slightly apiculate at the apex, not contricted in the middle, usually white; inflorescence rachis usually white	Conostegia superba
77 '	Flower buds apiculate at the apex, constricted in the middle, usually pink; inflorescence rachis pink	Conostegia rhodopetala
75'	Flowers not clustered at the end of the inflorescence branches; flower buds 10 mm long or usually longer; Southwest Mexico (Guerrero and Jalisco) or Jamaica
78	Leaf margin serrulate and cilate; pedicels 2-5 mm long; plants from Southwest Mexico (Guerrero and Jalisco)	Conostegia jaliscana
78'	Leaf margin not serrulate and cilate; pedicels 5-13 mm long; plants from Jamaica
79	Hypanthium ribbed, at least towards the base; abaxial leaf surfaces with tuft domatia at the base	Conostegia procera
79'	Hypanthium not ribbed at the base; abaxial leaf surface lacking tuft domatia at the base
80	Petals pink	Conostegia balbisiana
80'	Petals white	Conostegia pyxidata