Almeda: Systematics of the Genus Monochaetum () 51

Almeda 729 (BM, CR, DUKE, F, GH, MO, MSC, NY, US, USF); 18.2 km beyond El Empalme, Almeda 107U (CAS, DUKE, FSU, LL, MICH, US, WIS); ca. 19-20kmNWof Cerro Asuncion on C. R. #2 on Cor- dillera de Talamanca, Almeda 9 Flowers 2099 (DUKE, F, K, P, W); 10.6 mi beyond El Empalme on Cor- dillera de Talamanca, Almeda 9 Wilbur 1607 (DUKE); ca. 16 km SE of El Empalme, Almeda 9 Wilbur 16)4 (KM, BR, DUKE, F, G, GH, MEXU, MO, US); Panamerican Hwy between Km 18-20 from El Em- palme to Villa Mills, Cruz 28 (F); near Rio Colon between San Isidro and Colon on Cordillera de Tala- manca, Spellman et al. 525 (MO, SIU); above San Isidro de General, Sauer 5155 (LA); cut-over montane forest at Km 75 ca. 21 km NW of Villa Mills on Panamerican Hwy, Wilbur 9 Stone 8784 (DUKE). Putative hybrids between Monochaetum talamancense and M. amabile. —COSTA RICA. Cartago-San Jose border: 19.1 km NW of Cerro Asuncion on Cordillera de Talamanca, Almeda 500 (DUKE, 2 ); 8.1 mi beyond El Empalme on Cordillera de Talamanca, Almeda 9 Wilbur 1486 (DUKE); 10.6 mi beyond El Em- palme on Talamanca mts, Almeda 9 Wilbur 1606 (DUKE, 4 plants). 6. Monochaetum neglectum Almeda, sp. nov. (Fig. IS) Suffrutex diffusus ad 1 -5 mm altus; rami dense strigosi et 2-3 m longi, trichomatibus omnino ebarbellatis vel barbellatis et 0.5-2.5 mm longis. Foliorum lamina elliptica vel elliptico-lanceolata, (1.2-)1.9-5.0(-6.2) cm longa et (5-)8-18(-20) mm lata, plerumque (3-)5(-7)-plinervata, pari exteriore inconspicuo. Inflorescentiae terminales et axillares, dichasiales, bracteis ellipticis vel ovatis, (3-)7-14(-21) mm longis et 2-8 mm latis. Cal- ycislobilanceolati, 4-5.5(-6) mm longi et (2-)2.5-S mm lati, persistentes. Petala rosea, obovata, 1.0-1.4 cm longa et (7-)9-10.5 mm lata. Staminum maiorum filamenta 8-10 mm longa, thecis 5-7(-8) mm longis, appendicibus dorsalibus 3-5 mm longis. Staminum minorum filamenta 7-9.5 mm longa, thecis 4.5-5.5 mm longis, appendicibus dorsalibus 2-4.5 mm longis. (maturum) urceolatum, 5-6(-7) mm longum «4-6.5 mm latum, hirsutum, trichomatibus ebarbellatis plerumque glandulosis. Semina 0.5 mm longa, atrobrunnea, nitida, cochleata. Diffuse, sprawling, or trailing subshrubs to 1.5 m tall, branches 2-3 m long, terete with young shoots held at an angle of 65-90°; internodes (especially of young shoots) copiously appressed, strigose, or substrigose; trichomes glossy, white to pinkish, ebarbellate or minutely barbellate distally, 0.5-2.5 mm long. Nodal tri- chomes spreading, l(-1.5)mmlong, otherwise similar to internodal trichomes. Older stems woody, the bark not markedly exfoliating. Principal leaves membranaceous, entire, often anisophyllous; upper surface stri- gose in four to six well-defined, longitudinal belts of uniform width between the impressed primary nerves for at least the basal half of the blade, the outermost strigose belts confluent with adjacent ones distally (only four strigose belts present in smaller leaves); lower surface appressed-strigose on the elevated primaries and spreading, pilosulous, or glabrous between; blades narrow to broadly elliptic, elliptic-ovate, or elliptic-lan- ceolate, (1.2-)1.9-5.0(-6.2) cm long, (5-)8-18(-20) mm wide, acute apically, broadly acute to obtuse or rounded basally, prevailingly (3-)5(-7)-plinerved, the margins entire; petioles slender, 2-8 mm long, 1 mm wide, strigose. Inflorescence terminal on lateral branches, commonly a simple, three-flowered dichasium, or twice- to thrice-compounded, often reduced to solitary or paired flowers by abortion of lateral floral buds. Floral bracts reduced in size, elliptic to elliptic-ovate, acute apically, acute or obtuse to rounded basally, strigose in four longitudinal belts above, or pubescence absent basally but restricted to the upper two thirds, strigose on the three elevated primaries below and pilosulous between them, (3-)7-14(-21) mm long, 2-8 mm wide; petioles 0.5-S mm long. Floral pedicels 6-10(-12) mm long, strigose. Hypanthium (at anthesis) campanulate to suburceolate, moderately covered with widely to antrorsely spreading, smooth (often gland-tipped) trichomes, or the eglandular trichomes minutely barbellate apically; trichomes at the torus of the hypanthium (those along and between the base of the sepals) 2-2.5 mm long and commonly twice the length of those on the hypanthium proper. Hypanthium (at maturity) urceolate to suburceolate, 5-6(-7) mm long, 4-6.5 mm across at broadest point, eight longitudinal, vascular ribs often prominent on drying. Sepals broadly spreading to reflexed, lance-triangular, acute, ciliate, essentially glabrous without or with a few trichomes along the basal half, 4-5.5(-6) mm long, (2-)2.5-3 mm wide at the base, persistent. Petals pink, drying to shades of lavender or deep purple, obovate, mucronulate, remotely emarginate, or re- tuse (otherwise entire), often tipped with trichomes, 10-14 mm long, (7-)9-10.5 mm wide at the broadest point. Antepetalous staminalfilaments 5-7 mm long; anthers deep pink to pinkish-orange, 5-7(-8) mm long, 0.7-1.0 mm wide; apical pore 0.2-0.5 mm in diameter; appendages yellow, falcate to clavate, distally di- lated, 3-5 mm long, 0.5 mm wide. Antesepalous staminal filaments 7-9.5 mm long; anthers yellow, flushed with pink basally, 4.5-5.5 mm long, 0.5-1.0 mm wide, apical pore 0.2 mm or less in diameter; appendages yellow, linear-elliptic to linear-oblong, entire, 2-4.5 mm long, 0.2-0.5 mm wide. Ovary (at maturity) ovoid 52 University of California Publications in Botany Almeda: Systematics ofth to obovoid, setose apically. Style 6-8 mm 1( cochleate; n= 18. Type. — COSTA RICA. Cartago Province: i 2480-2500 m, December 24, 1973, Aimed MICH, MO, NY, P, UC, US). Flowering. — December to February is the Habitat and distribution.— In Costa Ric Cordillera Central, the Cordillera de Talai ama, it has been collected only in the Prov Chorro Trail linking Boquete and Cerro 1 pastureland margins, wet thickets of secon Monochaetum neglectum diffei copious, appressed cauline trichc leaves, urceolate hypanthia, reflex The considerable variation in le; attributed to shading and moistur monly have long internodes, long long). Plants of exposed, sunny sit organs. Similar variations have be from a single were grown un Relationships. —Monochaetum includes M. talamancense and M. r branching, and dark brown, lateral this association, suggesting a comm resemble M. talamancense in leaf si 3-plinerved leaves, stout, appresse long) and larger petals (15-19 mm > were determined as M. floribundu markedly from M. neglectum in th minutely foveolate seeds with prorr Sympatry. — In southern Central. tain ranges with at least six other sp< of secondary vegetation limit the an east of Volcan Bani in western Pan chophyllum grow in close proximity of these species is extremely rare at with M. cordatum, M. floribundu Costa Rica on the Cordillera de Tal of Tapanti, but only M. floribundu ence, abundance, and spatial relati scopic fashion from one locality to Evidence for intergradation betw< canicum has been detected in two ar Costa Rica, M. neglectum occurs lo canicum is common at elevations of these two species (table 6) are rarely Fig. 13. Monochaetum neglectum. A, habit, X V£; B,F, abaxial surface of floral bracts, X 3; C,C, al. 2225 possess intermediate featun abaxial surface of representative leaves, X 2; D, mature hypanthium and calyx lobes, X 3; E, seeds, X If; H, petal, X 3; I, ovary and style, X ca. 4. (A-I from Almeda 9 Flowers 2109.) gestive of hybridization. Both of thes Almeda: Systematics of the Genus Monochaetum (Melastomataceae) 53 nations in Botany toobovoid, setose apically. Style 6-8 mm long. Seeds 0.5 mm long, dark brown, smooth and shiny, tightly cochleate; n= 18. Type. — COSTA RICA. Cartago Province: 5.3 km SE of El Empalme on the Cordillera de Talamanca, elev. 2480-2500 m, December 24, 1973, Almeda St Flowers 2109 (Holotype, DUKE; isotypes, BR, F, GH, K, MICH, MO, NY, P, UC, US). Flowering. — December to February is the peak period, but sporadic flowering may occur in other months. Habitat and distribution.— In Costa Rica this species is known from the slopes of Volcan Barba in the Cordillera Central, the Cordillera de Talamanca and its northern adjoining slopes E of Tapanti. In Pan- ama, it has been collected only in the Province of Chiriqui in an area NE of Volcan Barii along the Bajo Chorro Trail linking Boquete and Cerro Punta. It occurs between 1800-2500 m at disturbed roadsides, pastureland margins, wet thickets of secondary vegetation, and boggy areas (fig. 14).

Monochaetum neglectum differs from other Central American congeners by its copious, appressed cauline trichomes, elliptic, elliptic-ovate, or elliptic-lanceolate leaves, urceolate hypanthia, reflexed calyx lobes, and pale pink corolla. The considerable variation in leaf size, petiole length, and internode length can be attributed to shading and moisture availability. Plants of wet, shaded thickets com- monly have long internodes, long petioles (to 8 mm) and larger leaves (50-62 mm long). Plants of exposed, sunny sites have markedly smaller measurements for these organs. Similar variations have been produced in greenhouse cultures when clones from a single plant were grown under variable light and watering regimes. Relationships.—Monochaetum neglectum is central in a species group which includes M. talamancense and M. trichophyllum. The sprawling habit, ± divaricate branching, and dark brown, laterally compressed seeds provide compelling criteria for this association, suggesting a common ancestral stock. Certain forms of M. neglectum resemble M. talamancense in leaf size and shape, but the latter has deeply pigmented, 3-plinerved leaves, stout, appressed hypanthial trichomes, longer sepals (6-10 mm long) and larger petals (15-19 mm x 13-15 mm). Previous collections of M. neglectum were determined as M. floribundum or M. macrantherum. The latter species differ markedly from M. neglectum in their erect habit, barbellate cauline trichomes, and minutely foveolate seeds with prominent lateral gyrations. Sympatry. —In southern , M. neglectum occurs on the same moun- tain ranges with at least six other species, but its localized populations in dense thickets of secondary vegetation limit the amount of close sympatric contact. In an area north- east of Volcan Baru in western Panama, M. cordatum, M. floribundum, and M. tri- chophyllum grow in close proximity to M. neglectum, but field studies reveal that each of these species is extremely rare at that station. Monochaetum neglectum also grows with M. cordatum, M. floribundum, M. macrantherum, and M. talamancense in Costa Rica on the Cordillera de Talamanca and its northern foothills and valleys east of Tapanti, but only M. floribundum occurs abundantly at these localities. The pres- ence, abundance, and spatial relationships of the various species change in kaleido- scopic fashion from one locality to another, varying the potential for hybridization. Evidence for intergradation between M. neglectum, M. floribundum, and M. vul- canicum has been detected in two areas. On Volcan Barba of the Cordillera Central in Costa Rica, M. neglectum occurs locally at elevations between 6100-8100 ft. M. vul- canicum is common at elevations of 7300-9500 ft. Within this narrow zone of overlap these two species (table 6) are rarely close associates, but Almeda 441 and Almeda et , F abaxial surface of floral bracts, X 3; C,G, al. 2225 possess intermediate features or a mixture of parental characters highly sug- ypanthium and calyx lobes, X 3; E, seeds, X 16; gestive of hybridization. Both of these putative hybrids have a suberect habit, subqua- neda 9 Flowers 2109.) Almeda: Systematics of the C

Character Differences Between

Monochaetum neg/ectu

Habit Trailing or sprawling subshr

Distal Terete, held at an angle of £ branchlets

Cauline Essentially smooth trichomes

Leaf shape Elliptic to elliptic-lanceolate

Hypanthial Urceolate shape

Hypanthial Spreading trichomes

s Seeds Dark brown, vernicose, some semicircular, laterally compr

If drangular distal branchlets held at an leaves, campanulate hypanthia, and se A different situation was found apprc Cordillera de Talamanca in Costa Ric; suited in the growth of several low, sh I £ 2 areas, shallowly banked streams, and fo Si thickets harbored an unusually large pc open areas harbored an equally large p microhabitats allowed establishment o 5 although its extent was limited to an ai "8 In an attempt to assess the extent of: for a number of salient morphological fe character differences between these spec: types in early generation hybrids cannoi distinguish between later generation pro would be arbitrary on the basis of preseni bo E sive introgression has not been a major Individuals in hybrid index classes 6-K (appendix 8). Some plants in these cla others equal parental values. Although swarm is unknown, the lack of consistent diacy and reduced pollen stainability sugg factors. Monochaetum floribundum differs mo: ecological preference than it does from presence of some highly fertile intermedi flow back to M. floribundum and M. n Almeda: Systematics of the Genus Monochaetum (Melastomataceae) 55

TABLE 6 Character Differences Between Monochaetum neglectum and M. vulcanicum

Monochaetum neglectum Monochaetum vulcanicum

Habit Trailing or sprawling subshrub Erect

Distal Terete, held at an angle of 65-90° Quadrangular, held at an angle of 45° branchlets or less

Cauline Essentially smooth Distinctly barbellate trichomes

Leaf shape Elliptic to elliptic-lanceolate Ovate, or obovate to ovate-elliptic

Hypanthial Urceolate Campanulate shape

Hypanthial Spreading Appressed trichomes

I Seeds Dark brown, vernicose, somewhat Orange-brown, minutely foveolate with a semicircular, laterally compressed dull luster, with prominent lateral gyrations

8> • drangular distal branchlets held at angles of 45-90°, barbellate trichomes, elliptic II leaves, campanulate hypanthia, and seeds like those of M. vulcanicum. It A different situation was found approximately 3 km southeast of El Empalme on the Cordillera de Talamanca in Costa Rica. The pattern of disturbance in that area re- il sulted in the growth of several low, shrubby thickets interspersed with open, grassy ' 8 areas, shallowly banked streams, and footpaths leading to adjacent pasturelands. The thickets harbored an unusually large population of M. neglectum and the contiguous open areas harbored an equally large population of M. floribundum. This mosaic of microhabitats allowed establishment of a hybrid swarm between the two species, although its extent was limited to an area less than half a hectare. o In an attempt to assess the extent of intergradation, this hybrid swarm was scored I for a number of salient morphological features (table 7). The mode of inheritance for 3 .0 character differences between these species is unknown, and the range of recombinant I types in early generation hybrids cannot be predicted with confidence. Any effort to Q distinguish between later generation progeny and early generation backcross progeny would be arbitrary on the basis of present information, but it seems certain that exten- sive introgression has not been a major manifestation of the hybrid zone (fig. 15). Individuals in hybrid index classes 6-17 show a considerable range in pollen viability (appendix 8). Some plants in these classes have marked reduction in fertility and others equal parental values. Although the basis of reduced fertility in this hybrid swarm is unknown, the lack of consistent correlation between morphological interme- diacy and reduced pollen stainability suggests that sterility is due to segregating genetic factors. Monochaetum floribundum differs more strikingly from M. neglectum in habit and ecological preference than it does from other species with which it hybridizes. The presence of some highly fertile intermediates implies that avenues still exist for gene flow back to M. floribundum and M. neglectum. The fact that hybridization can TABLE 7 Characters and Index Values Used in Scoring a Putative Hybrid Swarm Between Monochaetum floribundum and M. neg/ectum

Taxon and Index Value

Character floribundum (0) intermediate (1) neglectum (2}

Habit erect shrub semierect shrub sprawling or trailing subshrub

Branching angle ascendant, branchlets held at an angle intermediate, branchlets held at an 1 divaricate, branchlets held at an of 45° or less angle of 45° -65° angle of 65° -90°

Cauline pubescence retrorsely spreading antrorsely spreading closely appressed

Abaxial foliar trichomes antrorsely to widely trichomes narrowly spreading on the trichomes appressed on the primary pubescence spreading on the primary nerves primary nerves nerves

Uppermost floral bracts cordate to suborbicular, 3-5-nerved intermediate elliptic to elliptic-ovate, 3-nerved abaxially abaxially

Hypanthial pubescence appressed, barbellate trichomes appressed, distally barbellate antrorsely to widely spreading. trichomes essentially smooth (often gland- - tipped) trichomes

Sepal posture ascending spreading reflexed

Petal color white pale pink pink

Seeds orange-brown, dull and minutely dark brown, vernicose, oblong- dark brown, vernicose, tightly foveolate, oblong cochleate with cochleate with pronounced lateral cochleate and somewhat semicircular. pronounced lateral gyration gyration laterally compressed f™»— _ - -

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§CD Ico ra ICD IS

8 1 o o E a

* -5 23456 7 8 9 10 II 12 13 14 15 16 17 18 CO O HYBRID INDEX VALUE

Fig. 15. Frequency distribution of index values in a hybrid swarm between Monochaetum neglectum and M. floribundum.

ir> occur between these two divergent taxa substantiates the view that evolution within the ci genus has involved ecological and morphological differentiation without the establish- ment of strong reproductive barriers to interbreeding. .Q c 2 o Representative specimens. — COSTA RICA. Cartago Province: 11.6-20 km E of Orosi beyond Tapanti, Al- meda, Flowers 9 Wyatt 2174 (A, DUKE, F, MEXU, MICH, UC, US); 20-24 km E of Orosi, Almeda et al. 2««(DUKE, GH, MO, NY); 14-17 km E of Orosi, Luteyn 3942A (DUKE); along Hwy #224 ca. 14-17 km E > of Orosi, Luteyn 3944 (DUKE, F); 20 km beyond bridge over Rio Grande de Orosi at Tapanti, Luteyn et al. o 422#(DUKE). Cartago-SanJose border: 8 mi beyond El Empalme on Cordillera de Talamanca, Almeda & D. Wilbur 1476(KM., CAS, CR, DUKE, F, FSU, GH, LL, MICH, MO, NY, UC, US, USF, W, WIS); 4 km SE of El Empalme on Cordillera de Talamanca, Almeda 9 Flowers 2128 (CAS, DUKE, F, UC, US); S km SE of El Empalme on Cordillera de Talamanca, Almeda, Flowers 9 Wyatt 2359 (CAS, CR, DUKE, F, FSU, GH, K, LL, MEXU, MICH, MO, NY, US, W, WIS); 1-4 km S of El Empalme, Luteyn 3656 (DUKE); 2 km S of El Empalme, Wilbur 9 Luteyn 18365 (DUKE). Heredia: CR #11S, rd to Cerro Redondo de la Cruz, Almeda 448 (DUKE, GH, US); ca. 12 km N of San Rafael, rd terminus of CR #13 on slopes of Volcan Barba,

_Q Almeda 9 Wilbur 1058 (DUKE, F, GH, K, UC, US); 12 km N of San Rafael and 5 km N of Cerro Redondo a de la Cruz, Almeda 9 Wilbur 1503 (A, CAS, CR, DUKE, F, LL, MEXU, MICH, MO, US); slopes of Volcan Barba, 12 km N of San Rafael, Almeda 9 Wilbur 1505 (DUKE, US); IS km N of San Rafael, on slopes of Volcan Barba, Almeda et al. 2155 (DUKE); rd terminus of CR #114 on slopes of Volcan Barba, Almeda, Flowers 9 Wyatt 2227 (DUKE, F, US); Cerro Chompipe, N of San Rafael, Lems 6408-2502 (US); Yerba Buena, NE of San Isidro, Standley 9 Valeria 50074 (US); near Cerro Chornpipe between Rio Las Vueltas 58 University of California Publications in Botany Almeda: Systematics of the ( and Rio Nuevo, Wilbur S Luteyn 18589 (DUKE). San Jose: edge of sphagnum bog off Panamerican Hwy Monochaetum alpestre is infreque: between km 18-20 from El Empalme to Villa Mills, Cruz 28 (F - in part); La Chonta, Schnell 189 (F, US); vational distribution in relatively un< near Cantina La Lucha above Las Nubes, Schubert 9 Rogerson 641 (US). PANAMA. Chiriqui: Bajo Chorro trail linking Boquete and Cerro Punta, Almeda SI Wilbur 1596 (DUKE, LL, MO, NY, US); Bajo Mono distribution extending west to Guati trail, 7 mi N of Boquete, Wilbur Sf Luteyn 172)9 (DUKE). recent studies of the flora of Guatem Putative hybrids between Monochaetum neglectum and M. floribundum. — COSTA RICA. Cartago: ca. 5,J (Standley & Williams, 1963; William! km SE of El Empalme on Cordillera de Talamanca, Almeda 9 Flowers 2111 (DUKE, 6 plants); cut-over prior to the collections made by Brei cloud forest near La Sierra, ca. 25 km S of Cartago on Cordillera de Talamanca, Williams et al. 28032 (F, Monochaetum alpestre is notable f< NY, US). Cartago-SanJose border: ca. 1 mi beyond El Empalme on Cordillera de Talamanca, Almedai Wilbur 1478 (DUKE, 6 plants); 4 km SE of El Empalme on Interamerican Hwy, Almeda 9 Flowers till linear-oblong, straplike sepals that usi (DUKE, 5 plants); 3 km SE of El Empalme on Interamerican Hwy, Almeda, Flowers 9 Wyatt 2360 (DUKE, obovate petals fringed with barbellati 31 plants); 5 km SE of El Empalme, Wilbur 9 Luteyn 18333 (DUKE). sized by Naudin in the protologue. Putative hybrids between Monochaetum neglectum and M. vulcanicum. — COSTA RICA. Heredia: rd ter- races that coincide with geographica minus of CR #114 on Volcan Barba, ca. 2-2.5 km N on footpath toward the crater, Almeda 441 (DUKE); generally have leaves that are acute ; pastures at rd terminus of CR #114 on Volcan Barba, Almeda, Flowers 9 Wyatt 222} (DUKE). long, moderately appressed-strigose al 7. Monochaetum alpestre Naudin, Ann. Sci. Nat. II. 4:50. 1845 ulations from Chiapas have leaves tha 5-plinerved, (1.6-)2.1-3.5 cm long, i Type. — MEXICO. Oaxaca: Cordillera, elev. 8000 ft., Galeotti2930 (Holotype, PI; isotype, W!) anthers 5-6 mm long. The morpholog Erect shrub, or suffrutescent perennial mostly 1.5-S(-4.5) dm tall. Cauline internodes quadrangular, often in leaf size and an increase in anther becoming somewhat ridged or striate on drying, with a sparse covering of appressed, barbellate trichomei I Older stems woody, light brown, glabrate, the bark exfoliating. Principal leaves entire or obscurely crenu- j Monochaetum naudinianum Neum late, marginally beset with evenly spaced, minutely barbellate trichomes; dark green above, glabrous or I synonymy of M. alpestre by several au with scattered, appressed, barbellate trichomes along the distal half or two thirds of the blade; yellowish-1 1924) without comment. Gleason (19S green and punctate below on drying, with a sparse covering of barbellate trichomes along and sometimei I his synoptic treatment of the genus. 1 between the elevated primary nerves; blades elliptic, elliptic-lanceolate, or sometimes varying to ovate or was described from cultivated materia elliptic-ovate, 1.1-3.5 cm long, 4-13 mm wide, acute to acuminate apically, acute to attenuate basally, com- [ monly 3-nerved with all nerves arising from a common point at the base of the blade, or 5-plinerved with the I an unnamed area of Mexico. I have no three central nerves elevated and the marginal pair of nerves depressed and inconspicuous; petioles 0.5-) likely that a specimen was not preser mm long, 0.5 mm wide. Inflorescence terminal, a simple to once-compound dichasium, sometimes the flow logue. Monochaetum naudinianum is ers solitary or rarely arranged in a twice-compound dichasium. Floral bracts much reduced upward; lower- M. calcaratum because both share delt most bracts essentially identical to the principal leaves; uppermost bracts elliptic to ovate, glabrous, 4-11 than the hypanthium, larger floral pai (-12) mm long, 2-5(-8)mm wide, subsessile or with petioles 0.5-1.5 mm long, acute apically, acute to obttue basally. Floral pedicels covered with appressed to antrorsely spreading, barbellate trichomes, 5-8(-ll) mr» ers. Plants of the latter species have b long. Hypanthium (at anthesis) urceolate to suburceolate, deep carmine-red, with appressed to antrorselj Brussels. Herbarium specimens were p spreading, barbellate trichomes. Hypanthium (at maturity) squally campanulate to urceolate or suburceo-1 stitution. Both of the specimens examir late, 5-7 mm long, 4-5.5(-6) mm wide. Sepals (on mature hypanthia) erect or ascending, deep red basally lanceolate leaves (10-17 x 3-4 mm) th but greenish distally, linear-oblong, acute to rounded apically, sparsely strigose to glabrate without, entirt strigose to glabrate on the primary nen but fringed with barbellate trichomes, (6-)7-9(-10) mm long, l-2(-3) mm wide at the base, equalling or I exceeding the hypanthia at maturity. Petals magenta or deep pink, drying to shades of lavender or purple, shape of these cultivated plants are ren obovate, truncate to emarginate or retuse apically, otherwise entire but fringed with barbellate trichomei, pestre. It is not surprising that they w< (14-)17-20 mm long, (11-)14-18 mm wide. Antepetalous staminal filaments 6-9 mm long; anthers magenti forms of M. calcaratum occur in natui or reddish above, suffused with pale yellow on the channeled, ventral surface, 5-9 mm long, 1 mm wide; | tioned above compares in all respects I apical pore 0.5-0,8 mm in diameter; appendages pale yellow, clavate and ± terete distally, 3-4 mm long, O.i Similarity between M. calcaratum and mm wide. Antesepalous staminal filaments (7-)8-10 mm long, anthers pale yellow, but often suffused with magenta at least basally, 3-6 mm long, 1 mm wide; appendages pale yellow, linear oblong to linear-elliptic, angular sepals, essentially smooth hy 2-4 mm long, 0.5 mm wide. Ovary (at maturity) ovoid. Style 5-7 mm long. Seeds cochleate, 0.50-0.75 ran anthers ([9-]10-13[-14] mm long) of J» long, minutely foveolate, coppery brown. alpestre. Flowering.—Flowering plants have been gathered in December and from May through August. My onlj Relationships.—Gleason (1929a, 192 field experience with this species was during the month of December. The Oaxacan populations studied group with a Costa Rican endemic, Mo were in profuse flower at that time. This seemingly bimodal phenological pattern may be a reflection of inadequate collecting. Sporadic flowering may occur throughout the year. bian species, Monochaetum strigosum ( Habitat and distribution.—Exposed areas along rocky, roadside banks, disturbed sites, brushy and steep, heterogeneous and appears to be an arti wooded slopes in the wet pine or pine-oak woodlands of Oaxaca and Chiapas, Mexico, at elevations ct. two other Mexican endemics, M. cando 2400-3000 m (fig. 12). group since all share a similar suffruti