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| Cycas ammonitia Agoo, Madulid & Linis, in Agoo, Madulid et Linis, 2026. |
Abstract
Cycas ammonitia Agoo, Madulid & Linis (Cycadaceae, Section Cycas, Subsection Rumphiae K.D.Hill) is described from Mansalay, Oriental Mindoro, Philippines. The species grows in seasonally dry semi-deciduous forests on steep ridges over calcareous soils derived from Jurassic ammonite-rich deposits of the Mansalay Formation. Morphologically, Cycas ammonitia resembles Cycas edentata de Laub. and Cycas nitida K.D.Hill & A.Lindstr. in having smooth sclerotesta and a spongy endotesta in the seeds. However, it is distinguished by its very short microsporophyll and megasporophyll apical spines and its unique inland habitat on ammonite-bearing rocks, unlike the coastal or littoral distribution of its relatives. A key to the Philippine species of Cycas subsection Rumphiae is provided.
Keywords: Cycas ammonitia, Cycadaceae, new species, Mindoro Island, Philippines, Subsection Rumphiae
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| Cycas ammonitia Agoo, Madulid & Linis, sp. nov. A. Habit. B. Bark. C. Leaf. D. Part of a leaf showing petioles. E. Cross-section of a leaflet. F. Microsporangiate strobilus. G. Microsporophylls. H. Megasporophylls. I. Terminal lamina of megasporophylls. J. Seeds (en = endotesta; ga = gametophyte; sa = sarcotesta; sc = sclerotesta). A – E and H–J from Agoo and N Rag-op 26-008 (PNH, DLSUH), F– G from Agoo and N Rag-op 26-009 (PNH, DLSUH). Scale bar: A = 1 m., B = 2 cm., C = 1 m., D = 10 cm., E = 1 cm., F = 30 cm., G = 3 cm., H = 20 cm., I = 5 cm., J = 3 cm. |
Cycas ammonitia Agoo, Madulid & Linis, sp. nov.
Diagnosis: Similar to Cycas edentata and C. nitida in having smooth sclerotesta and a spongy endotesta of the seeds; but differ significantly by its very short microsporophyll apical spine (0.1–0.5 cm long) and megasporophyll apical spine (0.5–0.7 cm long) vs microsporophyll apical spine at least 0.9 cm long and megasporophyll apical spine 1.5–4 cm long in Cycas edentata and Cycas nitida and its unique habitat in a semi-deciduous forest near creeks over ammonite-bearing deposits.
Etymology: The specific epithet ammonitia refers to the ammonite fossil deposits found within the Mansalay Formation that are dated as Middle to Late Jurassic (Aurelio et al. 2012; Andal et al. 1968). The unique calcareous geological substrate, to which this species is restricted, highlights the intimate link between the plant’s edaphic niche and its speciation.
Esperanza Maribel G. Agoo, Domingo A. Madulid and Virgilio Cutibar Linis. 2026. Cycas ammonitia (Cycadaceae), A New Species from the Ammonite-rich semi-deciduous forests in Mindoro Island, Philippines. Telopea. 30; 187–194. DOI: doi.org/10.7751/telopea22599 [2026-09-08]
