220) CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Piper citrifolium. HIGUILLO AMARGO. 
Collected at Atola Teja, between Bayamon and Toa Baja (No. 240). Very 
similar in general appearance to the form identified as P. aduneum, but agreeing 
with the present species in having the leaves smooth on both sides. 
Piper macrophyllum. 
Family Piperaceae; a shrub 12 to 20 feet (4 to 6 meters) high on rocky hills; 
known from Adjuntas. (Grisebach.) 
Piper marginatum. 
Known from Aguadilla. 
Piper peltatum. See Heckeria peltata. 
Piper umbellatum. See Heckeria umbellata. 
Piptadenia peregrina. CoJOBANA. 
Also known as Cojobilla. Family Mimosaceae; a tree 5 meters high; older 
growth covered with spines; found at Bayamon. (Stahl, 3: 144-152.) See note 
under Acacia angustiloba. 
Piptocarpha triflora. 
A composite shrub, known from Sierra de las Piedras. 
Piquete. See Bidens lencantha and Cosmos caudatus, 
Piriqueta cistoides. See Piriqueta villosa, 
Piriqueta ovala. See Piriqueta ovata. 
Piriqueta ovata. PIRIQUETA OVALA. 
Family Turneraceae. (Stahl, 4: 159.) 
Piriqueta villosa. PIRIQUETA, 
An herbaceous erect annual, 40 to 50 centimeters high, in dry sandy soil. 
(Stahl, 4: 157.) 
Pisonia aculeata. EscamBRon. 
Also called ‘‘ utia de gato,” or ‘‘ cat’s claw.”’ A spiny shrub belonging to the 
family Nyctaginaceae; reported from near Manati. 
Pisonia obtusata. MaAJAGuA QUEMONA. 
Also called *‘ palo de corcho.”’ An indigenous shrub. 
Pisonia subcordata. Pao BoBo, 
An indigenous tree reaching a height of 20 meters. According to Urban two 
forms, albida and gigantophylla, have been found in Porto Rico; reported from 
Barranquitas. (Urban, Add. 3: 318.) 
Pistia stratiotes. WATER-LETTUCE. 
Family Araceae; a floating, stemless, stoloniferous herb, known from near 
Manati. 
Pitajaya. See Cereus triangularis. 
Pitangueira. See Hugenia biflora. 
Pithecolobium filicifolium. CoJopana. 
Family Mimosaceae; a forest tree 10 meters high; leaves finely divided; spine- 
less. (Stahl, 3: 137.) 
Pithecolobium saman. SaMAn. 
Some writers state that the name *algarrobo”’ is applied to this species. A 
large, spreading tree, 15 to 20 meters high, planted for shade in yards and public 
grounds. The trunk is inclined to be short and thick, while the branches are 
horizontal and extremely long. According to Stahl the wood is not very hard, 
with the heart of a handsome red color, On account of its lack of durability it is 
very little used. The flowers appear in spring and summer, and all the growing 
parts are slightly hairy. (Stahl, 3: 154.) 
