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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 10 



4. Ovary and fruit conspicuously stipitate; pericarp thick, ligneous or baccate, 

 deeply and coarsely longitudinally ribbed; peduncles 1 cm or less long, con- 

 spicuously bracteate. 3. Lorostemon. 

 4. Ovary and fruit sessile; pericarp not ligneous, at maturity thin and chartaceous, 

 smooth, not at all longitudinally ribbed; peduncles much exceeding 1 cm in 

 length, essentially ebracteate. 4. Thijsanostemon. 

 1. Stamens aggregated in 5 phalanges, but the filaments connate throughout forming ;i 

 tube, only the anthers free; anther-groups erect, or at length rotate or reflexed; 

 style elongated, slender, cylindric, the 5 branches prominent and rotate in anthesis; 

 fruit ovate, 1 or 2 seed maturing; flower buds spherical, petals scarlet, not expand- 

 ing at anthesis. 5. Symphonia. 



1. Platonia Martius, Nov. Gen. et Sp. 3 : 168, tab. 289. 1829. 



Platonia insignis .Mart. Nov. Gen. et Sp. 3 : 168, tab. 289. 1829. 



P. grandiflora PI. & Tr. Ann. Sci. Nat. IV. 14: 297. 1860. 



P. insignis Mart. var. formosa K. E. Schultes, Bot. Mus. Leafl. 17: 18. 1955. 



Type. Para, Brasil, Martins 2569 (holotvpe M, photo NY; isotvpe M, photo 

 NY). 



Distribution. A large tree with yellow latex and handsome pink flowers, widely 

 distributed in the Guianas, the middle and lower Amazon Basin, and the lower 

 Rio Negro. The ripe yellow pericarp of the fruit is edible. 



P. grandiflora PI. & Tr. (I.e.), based on a specimen (specimens?) in herb. Mus. 

 Paris marked "Bresil, " bearing- the hied, designation "Symphonia grandiflora 

 Choisy, " was distinguished chiefly because of presumed quantitative difference 

 of size of flowers and flower parts. 



The var. formosa was described as having the petal margins strongly involute. 

 The type has not been available to me. 



This fine forest tree is quite variable in the size and form of its leaves, and 

 in the size of its flowers. A review of the materials at Harvard, the U. S. National 

 Herbarium and at New r York does not lend evidence of any specific or varietal 

 segregation. 



2. Moronobea Aublet, Hist. PI. Guiane Fr. 2 : 789. 1775. 

 Type species. M. coccinea Aubl. 



In America, Moronobea is the largest genus of the Moronoboideae, and is 

 confined to the Guianas and the basins of the Amazon, Negro and Orinoco Rivers. 

 Its several species, especially M. coccinea and M. riparia, provide a copious yellow 

 latex, as do Symphonia and Platonia, that is employed by Indians and local 

 people as a caulking for river boats, an adhesive in instrument fabrication, and a 

 pitch for torch lighting (see Schultes, Bot, Mus. Leafl. 17 : 12-24. 1955) . 



Engler and following him, Vesque, the last two students to consider the genus 

 in its entirety, gave much taxonomic w 7 eight to the number of anthers per 

 phalange. Both of these authors considered the anther number to be sufficiently 

 constant to form the basis of key separation and indeed species delimitation. 

 From the considerably more material that is now available, and especially from 

 the examination of the flowers of many trees by me in the field, it has become 

 clear that the number of anthers per phalange is variable, even in flowers of the 

 same tree, and accordingly has little diagnostic value. The form of anthers and 

 their orientation is of much greater usefulness for specific delimitation. 



