STANDLEY TREES AND SHRUBS OF MEXICO. 37 



Segments closely tomentose beneath, rarely glabrate with age 4. D. bifida. 



Segments not tomentose beneath. 



Pinnae 2.5 to 3.2 cm. broad ; segments narrowly oblong ; veins 12 to 15 

 pairs, flbrillose with rusty scales ; leaf tissues glabrous. 



5. D. underwoodiana. 

 Piannae 3 to 5.5 cm. broad; segments linear; veins 20 to 28 pairs, these 

 and the leaf tis.sues sparsely pilose with whitish stellate hairs. 



6. D. palmata. 



1. Dicranopteris bancroftii (Hook.) Underw. Bull. Torrey Club 34:252. 1907. 

 Gleichenia bancroftii Hook. Sp. Fil. 1 : 5. 1844. 



Mertensia bancroftii Kunze, Linnaea 18: 307. 1844. 



Gleichenia brunei Christ, Bull. Herb. Boiss. II. 5: 13. 1905. 



Dicrmiopteris brunei Underw. Bull. Torrey Club 34: 253. 1907. 



Mountains of Veracruz and Chiapas, southward to the Andes of South 

 America; also in the Lesser Antilles and Jamaica (the type locality), mainly 

 at 1,000 to 1,800 meters elevation. 



Primary pinnae 1 to 3 pairs, oblong, 1 to 1.5 meters long, 30 to 50 cm. broad, 

 bipinnate; pinnules very numerous; segments narrowly linear, 1.5 to 2.2 cm. 

 long, herbaceous, glabrous or nearly so, glaucous beneath ; sori 3 to 5-sporan- 

 giate. 



2. Dicranopteris flexuosa (Schrad.) Underw. Bull. Torrey Club 34: 254. 1907. 

 Mertensia flexuosa Schrad. Gott. Anz. Ges. Wiss. 1824: 863. 1824. 

 Mertensia rigida Kunze, Linnaea 9: 16. 1834. 



Gleichenia flexuosa Mett. Ann. Lugd. Bat. 1: 50. 1863. 



Gleichenia rigida Bomm. & Christ. Bull. Soc. Bot. Belg. 35': 174. 1896. Not 

 G. rigida J. Smith, 1841. 



Mountains of Veracruz, at about 1,300 meters altitude. Guatemala to Brazil ; 

 widely distributed in the West Indies, mainly at low elevations; near Mobile. 

 Alabama ; type from Brazil. 



Leaf axis 2 to"4 mm. in diameter ; primary branches several pairs, repeatedly 

 dichotomous, never developing a secondary axis, the internodes unequal, naked ; 

 pinnae glabrous ; segments glaucous beneath, linear, letuse, narrowly connected 

 at the dilatate base, revolute. 



3. Dicranopteris pectinata (Willd.) Underw. Bull. Torrey Club 34: 260. 1907. 

 Merteiisia pectinata Willd. Svensk. Vet. Akad. Handl. II. 25: 168. 1804. 

 Gleichenia nitida Presl, Rel. Haenk. 1: 70. 1825. 



Mertensia elata Desv. Mem. Soc. Linn. Paris 6: 201. 1827. 



Mertensia nitida Presl, Tent. Pter. 51. 1836. 



Mountains of Veracruz. General throughout tropical America, the type from 

 near Caracas, Venezuela. 



Leaf axis 3 to 6 mm. in diameter ; primary branches several pairs, stipulate, 

 repeatedly and unequally dichotomous, a false flexuous secondary axis formed 

 by the alternate production of the unequal secondary branches, the included 

 bud of each dichotomy always abortive ; segments oblong to linear-oblong, 

 pruinose beneath, glabrous, or the costa and veins .sparsely rusty-paleaceous. 



A variable species. 



4. Dicranopteris bifida (Willd.) Maxon, N. Amer. Fl. 16: 60. 1909. 

 Mertensia bifida Willd. Svensk. Vet. Akad. Handl. II. 25: 168. 1804. 

 Gleichenia bifida Spreng. Syst. Veg. 4: 27. 1827. 



Mertensia fulva Desv. Mem. Soc. Linn. Paris 6: 201. 1827. 



Dicranopteris fulva Underw. Bull. Torrey Club 34: 255. 1907. 



Mountains of Veracruz. Common and generally distributed throughout the 



