CERAMIALES: Delesseriaceae

(G)† Hypoglossum attenuatum Gardner
Dawson (1956) reported this species from the southern Marshall Islands [not listed in Tsuda & Wray (1977)]. Wynne et al. (1989) questioned Dawson’s (1954) record of this species from Viet Nam, but did not mention his 1956 record. Tsuda (1981b) included it in his checklist for Guam on the basis of an unnumbered specimen in GUAM-ML collected by L. Egerod; there are also vouchers from Maug, Rota, and Chuuk.
Hypoglossum barbatum Okamura
Hypoglossum caloglossoides Wynne & Kraft
Hypoglossum minimum Yamada
According to Wynne et al. (1989), Dawson’s specimens of H. minimum are Hypoglossum simulans; they do not comment on other records of this species in our region.
(G) Hypoglossum simulans Wynne, Price & Ballentine
[including Dawson’s specimens of H. minimum and both Dawson’s (1956) and Taylor’s (1950) specimens of Caloglossa leprieurii, according to Wynne et al. 1989.]

Habit on Udotea; arrow points to tetraporangial sorus (see photos below). Coral gardens (Agat Bay) 16 Feb 03.

4x, BF general view of thallus.

detail of tetrasporangial sorus, 20x DIC

40x, PH
Cells in phase contrast showing plastids and nuclei.

40x, DIC
Spermatangial sori. Specimen from GabGab, 16 Mar. 2003.

40x DIC
Apex, showing pattern of cell tiers including long-oblique divisions in the marginal row.

Branch growth:

40x DIC