Cladocolea molotensis Martínez-Ambriz & Lozada-Pérez, 2016

Martínez-Ambriz, Emmanuel & Lozada-Pérez, Lucio, 2016, Cladocolea molotensis (Loranthaceae), a new species for the cloud forest of Guerrero, Mexico, Phytotaxa 265 (2), pp. 151-156 : 153-155

Cladocolea molotensis Martínez-Ambriz & Lozada-Pérez , sp. nov.

Diagnosis: — Cladocolea loniceroides similis, sed foliis rotundatis vel obtusis base, crystallis calcii conspicuis superficie folii, floribus staminatis hexameris, floribus pistillatis tetrameris vel pentameris, petalis glabris, staminodiis inconspicuis vel absentibus.

Type: — MEXICO. Guerrero: Atoyac de Álvarez : El Molote (♂), 17° 25’ 2.4” N, - 100° 10’ 49.7” W, 1750 m elev., 10 dic 2001 (fl), L. Lozada 2616 (holotipo: FCME; isotypes: MEXU, ENCB) .

Perennial hemiparasitic shrubs, pendulous, with sympodial branching; stems erect, terete, brown-reddish, sulcate, puberulent, leaf scars conspicuous, epicortical roots absent. Leaves alternate to decussate, subsessile; blades ovate to lanceolate, (1.5–)2–2.8 × (0.5–) 1–1.8 cm, apex acute and sometimes acuminate, base rounded to obtuse, margins entire to repand, venation pinnate, indumentum of simple trichomes, only on the midrib and leaf margin, leaf surface rugulate, with the presence of conspicuous calcium oxalate crystals, stomata paracytic, with subsidiary cells striate. Inflorescence capituliform, determinate and axillary, 0.5–1.2 cm long, with 5–6 flowers, sometimes the female inflorescence has 1–3 flowers along the peduncle; peduncle 1–4 mm, puberulent with the presence of calcium oxalate crystals. Floral bracts triangular, 1–2 mm long, green sometimes reddish, pubescent, accompanied by only the lateral flowers. Pistillate flowers, 3–3.5 × 2–2.5 mm, actinomorphic, pentamerous or tetramerous, sessile. Calyx green, reduced to a calyculus with a dentate edge, with simple trichomes along the margin. Corolla greenish-white, 2–3 mm long, free petals, glabrous. Staminodes generally absent, if present inconspicuous. Ovary inferior, 0.7–0.8 × 0.5–0.8 mm, glabrous. Style straight to sigmoid, 2–2.5 mm long, stigma capitate. Staminate flowers, 3–4 × 2–3 mm, actinomorphic, pentamerous or hexamerous, sessile. Calyx green to yellowish-green, reduced to a calyculus with dentate edge, with simple trichomes along the margin. Corolla white, 2.5–3.2 mm long, free petals, glabrous. Stamens equal to the number of petals, adnate to the corolla, opposite the petals, inserted at two different heights, three of them ¾ up the petal and two (three in the case of hexamerous flowers) ½ up, arranged alternately. Anthers basifixed, 0.5–1 × 0.5–0.7 mm, dehiscence longitudinal. Ovary inferior, 0.5–0.8 × 0.5 mm, glabrous. Style slightly curved to ½, 1–1.5 mm long, stigma undifferentiated. Fruit not observed.

Distribution and Habitat: — Cladocolea molotensis ( Figure 1 ) is endemic to El Molote, Guerrero; its distribution is restricted to the southern region of the physiographic province of the Southern Coastal Range (Cervantes et al. 2001) in the Guerrerense region. It grows in the cloud forest, in an elevational range that goes from 1750 to 1800 m.a.s.l. Flowering of June to December.

Additional specimens examined: — MEXICO: Guerrero. Atoyac de Álvarez: Cañada al SO del Molote (♀), 17° 25’ 46.8” N ; - 100° 10’ 46.3” W, 1772 m elev., 3 Junio 2004 (fl.), R. de Santiago y L. Lozada 1288 ( FCME). El Molote (♂), 20 Junio 2007 (fl.), L. Lozada y J. Rojas 3365 ( FCME) .

Etymology: —The name of the species refers to the first site where it was collected, El Molote, the only site where this species is known.

Remarks: — Cladocolea molotensis differs from C. loniceroides (Van Tieghem) Kuijt (1975: 306) in the brown-reddish color of the stem, the leaf base rounded to obtuse, trichomes only in the midrib and the margin of the leaf, the presence of crystals in the leaf surface and the peduncle, foliaceous bracts absent, pistillate flowers tetramerous or pentamerous, glabrous petals and staminodes usually inconspicuous or absent in the pistillate flowers (Table I).

The differences between C. molotensis and C. stricta Kuijt (1975: 327) consist mostly of the leaf size, the leaf base rounded to obtuse, staminate flowers pentamerous or hexamerous, glabrous petals and the style slightly curved (Table I).

Finally, the differences between C. molotensis and C. coyucae Kuijt (1975: 282) are the lanceolate to ovate leaves, acute or apiculate apex, tetramerous to hexamerous flowers, dimorphic stamens and style straight to sigmoid (Table I).

C. molotensis is restricted to a cloud forest zone named El Molote, located in the physiographic province of the Southern Coastal Range (Cervantes et al. 2001) in the Guerrerense region ( Figure 2 ); thus, it shares its distribution with C. loniceroides ( Figure 2 ). However, the latter is found in a wider altitudinal range and in various vegetation types along the state, because of its capacity to parasitize various plant genera, while the only known host of C. molotensis is the genus Sebastiania Sprengel (1820:118) ( Euphorbiaceae ).

TABLE I. COMPARISON AMONG CLADOCOLEA MOLOTENSIS, C. LONICEROIDES, C. COYUCAE AND C. STRICTA, BASED ON THE DESCRIPTIONS FROM KUIJT, 1975.

Key to identify the species of Cladocolea from Mexico

1. Plants pubescent, tomentose, puberulous or papillose.......................................................................................................................2

- Plants glabrous or glabrate.................................................................................................................................................................9

2. Phyllotaxis alternate, leaves narrowly lanceolate to ensiform, papillose to puberulous indumentum, only tetramerous flowers.....3

- Phyllotaxis alternate to decussate, leaves lanceolate, ovate, obovate or orbicular, pubescent to tomentose indumentum, hexamerous, pentamerous, occasionally tetramerous flowers.........................................................................................................................4

3. Plants hermaphrodite, dimorphic inflorescences, the primary in the young growth with shape of dichasium, the secondary in the last year growth with shape of capitulum, foliaceous bracts present only in the lateral flowers .................................... C. dimorpha

- Plants dioecious, isomorphic inflorescences with shape of capitulum, male inflorescences shorter than the female, foliaceous bracts absent ....................................................................................................................................................................... C. coyucae

4. Inflorescences spiciform with 3–7 flowers, bracts deciduous............................................................................................. C. hintonii

- Inflorescences capituliform with 4–10 flowers, bracts persistent......................................................................................................5

5. Foliaceous bracts present, style contorted or convolute.....................................................................................................................6

- Foliaceous bracts absent, style straight or sigmoid............................................................................................................................7

6. Yellow-brown-colored stem, inflorescence 10–25 mm long, hexamerous flowers, rarely pentamerous, style contorted................... ..................................................................................................................................................................................... C. loniceroides

- Grey-colored stem, inflorescence 8–15 mm long, hexamerous flowers, style convolute............................................ C. microphylla

7. Leaves obovate to orbicular, apex mucronulate to rounded, sometimes retuse ..................................................................... C. kuijtii

- Leaves lanceolate or ovate, apex acute, sometimes apiculate or acuminate......................................................................................8

8. Leaf size 1.5 x 0.7 cm or smaller, base acute, petals short pubescent................................................................................... C. stricta

- Leaf size 2–2.8 x 1–1.8 cm, base rounded to obtuse, petals glabrous............................................................................ C. molotensis

9. Epicortical roots absent, inflorescences dichasium, raceme, capitulum, occasionally flowers in dyads or triads...........................10

- Epicortical roots present, inflorescences in spike, rarely in raceme.................................................................................................15

10. Inflorescences with 2–4 flowers, each flower in a floral cupule......................................................................................................11

- Inflorescences with 3–14 flowers, flowers never in floral cupules..................................................................................................12

11. Leaves linear-lanceolate to falcate, venation hyphodromous, unisexual flowers ............................................................. C. cupulata

- Leaves lanceolate to ovate, venation pinnate, bisexual flowers........................................................................................... C. biflora

12. Inflorescences dimorphic, the primary in the young growth with shape of dichasium, the secondary in the last year growth with shape of spike, tetramerous flowers ................................................................................................................................. C. oligantha

- Inflorescences isomorphic, hexamerous flowers..............................................................................................................................13

13. Stems quadrangular and sulcate, inflorescences capituliform, sessile flowers ............................................................... C. andrieuxii

- Stems cylindrical, inflorescences with shape of raceme, pedicellate flowers..................................................................................14

14. Phyllotaxis alternate, rarely decussate, determinate inflorescence with 7–9 flowers, pedicel 4–7 mm long ............... C. pedicellata

- Phyllotaxis decussate rarely alternate, indeterminate inflorescence with 10–14 flowers, pedicel 0.5–2 mm long ........ C. racemosa

15. Foliaceous bracts present, the male inflorescence in spike with 4–7 flowers, the female inflorescence in raceme with 3–6 flowers ....................................................................................................................................................................................... C. diversifolia

- Foliaceous bracts absent, inflorescences only in spikes with 3–14 flowers.....................................................................................16

16. Phyllotaxis alternate, inflorescences with leaves in the base of inflorescence.................................................................................17

- Phyllotaxis decussate to alternate, inflorescences without leaves in the base of inflorescence.......................................................19

17. Leaves ensiform, inflorescence with a whorl of leaves in the base of inflorescence.......................................................... C. gracilis Leaves lanceolate, oblanceolate or obovate, inflorescences with one or two leaves in the base of inflorescence...........................18

18. Female inflorescence less than 1 cm long, with 6 flowers per inflorescence, hexamerous flowers .................................... C. glauca

- Female inflorescence up to 3 cm long, with 5–8 flowers, pentamerous or hexamerous flowers............................. C. tehuacanensis

19. Petiole winged, leaves without nerves at the base, flowers arranged perpendicularly to the inflorescence axis........... C. mcvaughii

- Petiole not winged, leaves with multiple nerves at the base, flowers arranged opposite to alternate to the inflorescence axis......20

20. Spikes always determinate, floccose trichomes present in the adaxial surface of the petals, fruit 10 mm long or more .................... .......................................................................................................................................................................................... C. grahamii

- Spikes generally indeterminate, sometimes determinate, floccose trichomes absent in the adaxial surface of the petals, fruit up to 5 mm long........................................................................................................................................................................... C. pringlei

Figures

FIGURE 1. Cladocolea molotensis. A) Habit, B) Female inflorescence, C) Pistillate flower, D) Staminate flower. (A and D based on L. Lozada 2616; B and C based on R. de Santiago y L. Lozada 1288; drawn by Teresa Jiménez).

FIGURE 2. Distribution map of C. molotensis and C. loniceroides in Guerrero, considering physiographic region.