STANDLEY ALLIONIACEAE OF MEXICO. 387 



Anthocarp 7 to 14 mm. long, the glands in a single row. 

 Staminate inflorescence with 10 flowers or fewer; pe- 

 duncles 2 or more together 3 . P.fasciculata. 



Staminate inflorescence with numerous flowers, the pe- 

 duncles solitary. 

 Staminate flowers in compact corymbs 10 to 

 22 mm. in diameter, dark red. 

 Leaves broadly rounded or obtuse, orbicular 

 or obovate, usually densely pubescent 

 on both surfaces ; spines mostly curved.. 4. P.capitata. 

 Leaves acute or acutish, oblanceolate, mostly 



glabrous ; spines straight 5 . P. fiavescens . 



Staminate flowers in loose, open corymbs 25 to 60 

 mm. broad; flowers yellowish green. 

 Leaves not oblanceolate, 25 to 85 mm. long. . . 6. P. aculeata. 

 Leaves oblanceolate, 110 to 150 mm. long 7. P. grandifolia. 



1. Pisonia donnellsmithii Heimerl in herb. 



Branches stout, yellowish, unarmed, glabrous or the youngest sparingly pubescent) 

 densely leafy; leaf blades bright green, thin, elliptic to oblanceolate, 30 to 55 mm. 

 long, 12 to 28 mm. wide, acutish or acute, cuneate at the base, glabrous except on 

 the principal veins, there tomentulose, on tomentulose petioles 4 to 8 mm. long; 

 staminate flowers subumbellate, the heads 2 cm. broad or less, the flowers on short 

 viscid-puberulent pedicels 1 mm. long or less; peduncles 22 to 30 mm. long; perianth 

 5 mm. long, very narrowly campanulate, minutely puberulent without, 5-lobed at 

 the mouth, the lobes obtuse; pistillate flowers and fruit not seen. 



Type in the TJ. S. National Herbarium, no. 1810, collected at Los Verdes, Depart- 

 ment of Amatitlan, Guatemala, at an altitude of 1,050 meters, October, 1893, by 

 Heyde & Lux (no. 6301). 



The species was given this name by Doctor Heimerl in the National Herbarium 

 and has been used by him in correspondence but, apparently, has never been pub- 

 lished. The plant can not well be compared with any other species of the genus, its 

 dense inflorescence and peculiar perianth setting it off from all the rest. Possibly, 

 when the fruit and pistillate flowers are known it will be found that it does not belong 

 in the genus Pisonia. The specimens were distributed as Pisonia macranthocarpa, 

 it being believed that they represented the staminate inflorescence of that plant. 

 The mere form of the leaves should make such a view untenable and besides this the 

 writer has seen reliable staminate material of P . macranthocarpa elsewhere, showing 

 it to be far different from these specimens. 



2. Pisonia macranthocarpa J. D. Smith, Bot. Gaz. 20: 293. 1895. 

 Pisonia aculeata macranthocarpa J , D. Smith, Bot. Gaz. 16: 198. 1891. 

 Pisonia aculeata pedicellaris Griseb.; Heimerl, Bot. Jahrb. Engler 21: 633. 1896. 

 Pisonia pedicellaris Griseb.; Heimerl, Jahresb. Oberrealsch. Funfhaus 23: repr. 32. 



1897. 

 Type locality, "Escuintla," Guatemala. 



Specimens examined: 



Nicaragua: 1853-56, C. Wright. 



Costa Rica: Environs de Nicoya, December, 1900, Tonduz 13783; paturages de 



Nuestro Amo, llanos de Turrucares, January, 1902, Pittier 1522, alt. 700 meters. 

 Guatemala: Escuintla, Depart. Escuintla, alt. 330 meters, April, 1890, J. D. 



Smith 2091, type; same locality, alt. 330 meters, February, 1892, J. D. Smith 



1230; Aguascalientes, Depart. Santa Rosa, January 24, 1908, Kellerman 7077; 



Paso de Lelha, Valley of Copan, alt. 550 meters, January, 1907, Pittier 1819; 



vicinity of Zacapa, Depart. Zacapa, alt. 200 to 400 meters, 1906-7, Pittier 



1734a. 

 84645°— vol 13, pt 11—11 2 



