Mr D. Don on the Affinit'us of' Lipostoma, Sfc. 169 



2. L. sericeum, pilis adpressis, foliis ovatis acutis. 

 Hab. in Brasilia. Sella. {v. s. sp. in Herb. Lamb.) 

 Planta tota pilis adpressis vestita, subsericea. Radix tibrosa, annua. CaulU 

 seniipedalis, divisus. Rami teretes, patuli. Folia opposita, petiolata, ovata, 

 acuta, membranacea, basi parum attenuata, pinnate nervosa, costa media sub- 

 tiis prominula nervisque alternis oppositisve subarcuatis instructa, sesqui- v. 

 bipoU'caria ; juniora subsericea. Petioli semicylindrici, vix unciales, basi an- 

 nulo connati. StipulcB setaceae, petiolo duplo breviores. Capitula duplo mi- 

 nora, pedunculata. Pedtmculi capillares, folio longiores, sericeo-pilosi. Ca- 

 lycis denies setaceae. Corolla paul6 minor, pilosa, calyce duplci longior. Cap- 

 sitltB operculum liberum, nee calycis limbo connatum. Semina triquetra, atro. 

 fusca, elevato-punctata. 



I was led to investigate this genus, from remarking the strik- 

 ing resemblance of Lipostoma capitatttm to Pomax umbellata, 

 and the result has proved that there really exists a very consi- 

 derable degree of affinity between these two plants, and that 

 they form, as it were, the links connecting the Rubiacea to the 

 Opercular ina, which Mr Brown is disposed to keep united ; 

 and, indeed, I cannot see by what characters the Opercularina 

 can well be separated, unless as a section only, as Mr Brown 

 has already suggested : for their habit is entirely Rubiaceous ; 

 and we frequently find in Spermacoce the same variation in tiie 

 number of stamina and in the divisions of the corolla; and a 

 somewhat similar involucrum may be observed in Canephora. 

 The anomalous structure of their fruit is derived from the early 

 rupture and confluence of the ovaria and calyces, which consti- 

 tute the operculum. The seeds in Opercularia and Pomax are 

 attached to the base of the receptacle, and not suspended from 

 the top, as Gaertner has stated. From observing the various 

 degrees of confluence in the fruit of certain Rubiaceee, such, for 

 example, as Morinda and Sarcocephalus, and even in some spe- 

 cies of Spermacoce, the singularity of the fruit in Opercularia 

 and Pomax is very much lessened ; and we are led to anticipate 

 a similar state of the ovaria, rather than to regard it as a re- 

 markable anomaly. 



DEUTZIA, Thunb. 

 Stjst. Linn. DECANDRIA TETRAGYNIA. 

 Ord. Nat. PHILADELPHEyE, nobis. 

 Calyx campanulatus, 5-dentatus : dentibus ovatis, acutis, erectis. Petala S, 

 laciniis calycinis altcrna, scssilia, oblonga, ohtusa, pube stellata tomentosa. 



