244 MERRILL. 
CONVOLVULACEAE. 
iPOMOEA Linn. 
IPOMOEA REPTANS (Linn.) Poir. in Lam. EncycL Suppl. 3 (1814) 460. 
Convolvulus reptans Linn. Sp. PI. (1753) 158, pro parte. 
This species is very common and widely distributed in the Philippines, 
but there is some doubt as to its proper specific name. The question is 
one of an interpretation of types only. Hallier f." states that the specimen 
of Convolvulus reptans in the Linnean Herbarium is Merremia caespitosa 
Hallier f. Dr. C. B. Robinson has kindly verified this for me, and confirms 
Hallier's opinion; he also writes that the species is listed by Linnaeus in a 
manuscript catalogue of his herbarium (1755), as being then in his 
possession, so that there is every reason to believe that the specimen was 
in Linnaeus* hands when he wrote the ^'Species Plantarum." However, he 
assumed that a certain plate in Rheede's "Hortus Malabaricus" was the 
same as the specimen in his herbarium, and in his descriptions cites the 
reference to Rheede first. Now Ballel Rheede Hort. Malabar. 1 1 : 107, t. 52 
is unquestionably the plant usually known as Iponiea reptans Poir. (/. 
aquatica Forsk.), and this reference has been accepted by all botanists up 
to the present date as typifying the Linnean species. The sole question is, 
whether the specimen in the Linnean herbarium is the type of his Con- 
volvuhis reptans, or is the species typified by the reference to Rheede* work. 
The case seems to be very nearly balanced, but if an arbitrary rule be 
followed and the first reference to a plate be taken as typifying the species, 
then the reference to Rheede typifies the species; but on the other hand the 
specimen in the Linnean herbarium may be interpreted as the type, for 
Linnaeus undoubtedly possessed the specimen at the time the "Species 
Plantarum" was written. If the reference to Rheede be taken as the type, 
then no change pf name is necessary, but if the specimen in the Linnean 
herbarium be taken as the type, then two changes are necessary, first the 
adoption of the binomial Ipomea aquatica Forsk., to designate the species 
now commonly known as 7. reptans Poir., and secondly the transfer to 
Convolvulus reptans Linn, to Merremia, as the oldest specific name of 
Merremia caespitosa Hallier f. In order to avoid any change of name, the 
reference to Rheede has been accepted by me as typifying Ipomea reptan9 
(Linn.) Poir. (7. aquatica Forsk.). 
MERREMIA Dennst. 
MERREMIA HIRTA (L.) comb. nov. 
Convolvulus hirtus L. Sp. PL (1753) 159; Hallier f. Meded.s' Rijks 
Herb. (1910) 21. 
Convolvulus caespitosus Roxb. Hort. Beng. (1814) 14, nomen, Fl. Ind. 
2 (1824) 70. 
Ipomoea linifolia Blume Bijdr. (1825) 721. 
Skinneria caespitosa Choisy Conv. Or. (1825) 105, t. 6, DC. Prodr. 9 
(1845) 435. 
Merremia caespitosa Hallier f. in Engl. Bot. Jahrb. 16 (1893) 552. 
Ipomoea philippinensis Choisy I. cc. 93, 367. 
This widely distributed and variable species is common in the Philippines, 
what is assumed to be the earliest valid specific name being here adopted. 
u 
Meded.'s Rijks Herbarium (1910) 21. 
