Cryptangieae Benth.

Costa, Suzana M., Vitta, Fabio A., Thomas, William W., Muasya, A. Muthama, Morokawa, Rosemeri, Bittrich, Volker, Shepherd, George J. & Do Amaral, Maria Do Carmo E., 2021, An updated generic circumscription for Cryptangieae (Cyperaceae, Poales) based on a molecular phylogeny and a morphological character reconstruction, Phytotaxa 483 (3), pp. 211-228 : 222

Cryptangieae Benth. in J. Linn. Soc. London, Bot. 18: 366. (1881).

Monoecious or dioecious herbs, sometimes developing a caudex (a more or less lignified vertical stem covered by sheaths remains and adventitious roots). Leaves are basal and linear or less frequently reduced to sheaths. The inflorescence are spike-like, head-like or panicle-like with conspicuous paracladia (inflorescence panicle-like ramifications subtended by bracts), which can be monomorphic or dimorphic [see dimorphic paracladia at Figure 2J ]. Flowers and spikelets are unisexual: male spikelets are generally pluriflowered while female spikelets are frequently uniflowered; with spiral (rarely distic) glumes. The stamens may be yellow or pinkish, but the stigma are pinkish-red (except in some populations of Chapada Diamantina — Bahia, BR). The fruit is a nutlet with two or three sides, and usually with fimbriate/ciliate, conspicuous/inconscipuous hypogynous scales and a beak.

The morphological recognition of Cryptangieae genera after the molecular phylogeny cannot rely on a single character, but depends on the combination of two or more characters. When used in isolation or with different character weights ( Gilly 1941a, 1941b, 1942, 1951; Koyama & Maguire 1965; Koyama 2003, 2004; Vitta 2005 —PhD thesis) they led to an artificial circumscription of the genera.

We are working on an ancestral area analysis, but it is worth to mention that Cephalocarpus , Exochogyne and Didymiandrum mostly occur in the Amazon region. Cryptangium is spread in C & S America and Lagenocarpus shows widespread species, a group of species from only Amazon areas and another group restricted to the campos rupestres.

Krenakia species are mostly restricted to the campos rupestres. Two intriguing cases are Krenakia venezuelensis , from the Guiana Shield, and K. cubense , that occurs only in Cuba, and may be investigated in the future. These are two cases of disjunction in the distribution of Krenakia . Both also present unique morphological character states within the genus: K. cubense is probably dioecious and K. venezuelensis has densely lanose leaf sheaths and stamens connate by the fillet. Unfortunately, there is no DNA sequence available or other evidence of these species to support their position in the genus without doubt.

Figures

FIGURE 2. Cryptangieae general morphology.A. Cephalocarpus confertus (habit), B-C. Cephalocarpus montanus habit (B) and caudex in cross section (C); D-E. Krenakia minarum habit (D) and detail of leaves reduced to sheaths (E); F-G. Exochogyne amazonica with mature male (F) and female (G) spikelets; H. Cryptangium verticillatum male spikelets; I. Krenakia sp. spikelets. J. Lagenocarpus rigidus inflorescence (female spikelets apical and in rigid peduncles and male spikelets basal and in flexible peduncles); K. Cephalocarpus confertus inflorescence detail (male and female spikelets at the same cluster); L. Cephalocarpus montanus uniflowered spikelets with immature nutlets.